’ ■■ \ ■ :-;-s ••'s ;; - s •'< . ; : -- ■ ■ • A';. V :\Z-XJ ['Cl-lU ;J -‘Ci; 'a - ; : ;r A : "r\ ’ fv I * * « J ]\ ’’ f. r~ ;'a “ f> * f*** V./ , Lj/ 1. Ks I L V V I \ k . **J '• X . . w —i’ « ... \ I W lU.. I'vJ L \ ' rf ■ > ■ ',J ■- C^C7'. “0 r.; ■— L ...; MAYO AERO MEDICAL UNIT • ** STUDIES IN AVIATION MEDICINE Carried out with the assistance of the NATIONAL RESEARCH COUNCIL, DIVISION OF MEDICAL SCIENCES acting for the COMMITTEE ON uEDICAL RESEARCH of the OFFICE OF SCIENTIFIC RESEARCH AND DEVELOPMENT COMMITTEE ON AVIATION MEDICINE With the cooperation of the • \ UNITED STATES ARMY AIR FORCES, MATERIEL COMMAND, WRIGHT FIELD. Responsible Investigators: Walter M, Boothby, E. J# Baldes and C, F, Code aided by many associates# In Six Volumes These reports, originally in "restricted” classification, have been declassified and all are now "open,” VOLUME kt SERIAL REPORTS TO AAF MATERIEL COMMAND, SERIES A, NOS. 1 to lm Mayo Clinic and Mayo Foundation for Medical Education and Research, University of Minnesota Rochester, Minnesota 19UO - 19U5 COMMITTEE ON WAR MEDICINE, MAYO ASSOCIATES representing the MAYO CLINIC AND MAYO FOUNDATION FOR MEDICAL EDUCATION AND RESEARCH Dr, Balfour, Dr, C,W, Mayo*, Dr, R,D, Mussey, Dr. A,R, Barnes and Mr. H,J, Karwic STAFF OF THE MAYO AERO MEDICAL UNIT Responsible Investigators High Altitude Laboratory; Walter M, Boothby, Chairman. Member of the Subcommittee on Oxygen and Anoxia of the Committee on Aviation Medicine, National Research Council. Acceleration LaboratoryE.J. Baldes, Vice Chairman. Member of the Subcommittee on Acceleration of the Committee on Aviation Medicine, National Research Council. C,F. Code, Secretary* Member of the Subcommittee on Decompression Sickness of the Committee on Aviation Medicine, National Research Council. Investigators Staff of the Mayo Clinic and Mayo Foundation: (Full time) E,J. Baldes, J.B, Bateman, W,M. A.H, Bulbulian, C,F. Code. H,F, Helmholz, Jr,, E#H, Lambert, W,R, Lovelace, II and E*H, Wood, (Part time) J,D. Akerman,*** J, Berkson, H,B, Burchell, P,L, Cusick, H.E, Essex, C.A, Hallenbeck, W.W, Heyerdale, H,C. Hinshaw, J, Piccard,-'*■** M. Power, C, Sheard, J,H, Tillisch, M,N, Walsh and M.M.D, Williams, Fellows of the Mayo Foundation; R, Bratt, B,P, Cunningham, W#H, Bearing, E.TT, Erickson, N, Erickson, J,H, Flinn, J.K, Keeley, J, Pratt, F,J, Robinson, R.F, Rushmer, G,F, Schmidt, H.C, Shands, H,A, Smedal, A,R, Sweeney, A. Uihlein, H, Wilder, Jr,, J. Wilson and K,G. Wilson, Officer assigned by the Air Transport Command of the Army Air Forces: K,R, Bailey, pilot* Officers assigned by Air Surgeon’s Office: 0,0, Benson, Jr,, J,W, Brown, J,H, Bundy, D# Coats, E, Eagle, M,F, Green, J.R, Halbouty, H.B, Harding, J.P. Marbarger, M,M, Guest, O.C. Olson, C,M, Osborne, H, Parrack, N, Rakieten, J,A, Resch, H,A. Robinson, H,E, Savely, C,B, Taylor, L. Toth and J.W, Wilson, Officers assigned by the Navy: W, Davidson and D,W, Gressley, Officers sent by other governments: J.R. Delucchi, Argentina, and R,T, Prieto, Mexico. Other investigators: M, Burcham, C.J, Clark, M,A, Crispin, R,E . Jones, G, Knowlton, H, Lamport, C.A, Lindbergh, C ,A, Maaske, G,L, Maison, A, Reed and R,E. Sturm, Technicians High Altitude Laboratory: Henrietta Cranston, Lucille Cronin, Ruth Knutson, Eleanor Larson and Rita Schmelzer; Margaret Jackson (from Wright Field), Acceleration Laboratory: L, Coffey, H, Engstrom, H, Haglund and A, Porter; Ruth Bingham, Velma Chapman, Marjorie Clark, Wanda Hampel and Marguerite Koelsch. Secretaries Evelyn Cassidy, Esther Fyrand, Marian Jenkins and Ethel Leitzen. Before going into military service. The major reports of the Acceleration Laboratory will be published shortly in the monograph entitled "Tie Effects of Acceleration and Their Amelioration,” edited by the Subcommittee on Acceleration of the Committee on Aviation Medicine of the National Research Council, From the Department of Aeronautical Engineering, University of Minnesota, CONTENTS Reports to Army Air Forces Materiel Command. Serial Report Series A, No. 1# Observations, experiences and recommendations related to balling out at high altitudes* By W. Mc Boothby, K, Gc Wilson, 0, A, Lindbergh and C, J, Clark, 3 October 19U2. Serial Report Series A. No. la. Report on positive pressure breathing (a) constant pressure and (b) pulsating pressure (chest compression up to h cm. Hg for short periods 3 to h times during expiration) by Boothby and Lindbergh. By W, Me Boothby, 3 October 19U2. Serial Report Series A, No. 2. Indoctrination of 21 crews of the 30?th Bombardment Group. By W. M, Boothby, 30 October 19U2. Serial Report Series A, No. 3* Conservation of o;xygen affected by the use of economizer bag, and with and without the use of the automix. By C. B. Taylor, J. P. Marbarger, B. P. Cunningham, F. J. Robinson, A. R. Sweeney, K. G, Wilson and W* M, Boothby, 20 November 19U2. Serial Report Series A, No. U. ihe development of a positive pressure jacket for use during positive pressure breathing. By C, B. Taylor and J. P. Marbarger, 1 February 19^3. Serial Report Series A, No. Ua. The effect of positive pressure breathing on the arterial blood pressure, venous blood pressure and the cerebro-spinal fluid pressure in the dog. By J. P, Marbarger and C, B, Taylor, 9 February 19U3. Serial Report Series A, No. Ub. The effect of positive pressure breathing on the appearance of the retinal vessels and on the intraocular pressure in man. By C, B, Taylor and J. P. Marbarger, 17 February 19h3* Serial Report Series A, No. U b-2. Further studies on the effect of positive pressure breathing on the appearance of the retinal vessels in man. A supplement to Serial Report, Series A, No. i*b. By C. B. Taylor and J. P. Marbarger, 23 April 19U3« Serial Report Series A, No. Uc. The effect of breathing against 30-35 mm. Hg on the cardiac output. By E. W, Erickson, J. P. Marbarger and C. B. Taylor, 2U February 19U3* Serial Report Series A, No. Ud. Progress on arterial puncture studies at altitude breathing against positive pressure in the positive pressure jacket. By C# B. Taylor and J. P. Marbarger, 3 March 19U3# Serial Report Series A, No. Ue. Arterial b}.«od studies at altitudes up to $0,000 feet, breathing under positive pressure in the positive pressure jacket. By M. H# Power, C. B. Taylor and J. P. Marbarger, 11 March 19^3* Serial Report Series A, No. Uf. Progress on positive pressure jacket work. By C. B, Taylor and J. P* Marbarger, 20 March 19U3* 2- Serial Report Series A, No, Ug, The effect of breathing under positive pressure using the positive pressure rebreather bag. By E, W. Erickson, C, B, Taylor and J, P, Marbarger, 30 March 19U3« Serial Report Series A, No, l*h, Report of Liaison Officers, 1st Lt. C, B. Taylor, M.C., and 2nd Lt, J, P, Marbarger, AAF, attached to the Mayo Aero Medical Unit for activities from April 19 to May 5, 19U3. By C, Bo Taylor and Jc P, Marbarger, S May 19U3* Serial Report Series A, No, i*j, Arterial blood studies at altitudes of UU,000 and U6,000 feet, breathing under positive pressure with the Wright Field positive pressure mask and regulator developed by Major A, P, Gagge, A,C,, and his group. By M, H. Power, C. B. Taylor and J, P, Marbarger, May 19U3* Serial Report Series A, No, Uk. (l) Some preliminary observations on the partition •f the total respiratory volume during positive pressure breathing with and without the counter-support of a pressure jacket, (2) Some preliminary observations on the effect of pressure breathing on the oxygen saturation of arterial blood. By C, B* Taylor, M, H, Power, and J, P, Marbarger, May 19i*3* Serial Report Series A, No. h 1, Partial pressures of oxygen and carbon dioxide of blood sanples taken at simulated altitudes up to £0,000 feet, breathing under positive pressure in the positive pressure jacket. By M, H, Power, C, B* Taylor and J, P, Marbarger, 30 May 19U3« Serial Report Series A, No, Urn, A comparison of per cent saturation of arterial blood by chemical determination, to per cent saturation of arterial blood as determined by the oximeter. By F, J, Robinson, C, B, Taylor, M, H, Power and J. P, Marbarger, June 19U3. MAYO AERO MM CAL UNIT MEMORANDUM REPORT to ARMY AIR FORCES MATERIEL CTTTUh. Under Contract Mo, W535ac-25829 SUBJECT* Observations., Experiences and Recommendations Related to Bailing Out at High Altitudes; SERIAL REPORT- Series A, Ho* 1 DATE: October 3, 1942 A* Purposes I* To determine the need for emergency bail out equipment* 2* To determine the effect of removing the regular oxygen mask and using various types of jump bottle mouthpieces during emergency parachute jumps from' 35>a000 feet or more* 3* To discover a more satisfactory method of transfer from main oxygen supply to emergency cxygen equipment and reduce the mental and physical efforts of such a transfer to a minimum. 4. To design equipment which will permit aviators to jump from altitudes of at least 40*000 feet, even after intensive exercise and a period of interrupted flow of oxygen, without loss of consciousness. 5* To study the effects of breathing only air at 40,000 feet* B, Factual Data 1, The details of the simulated parachute jump tests are given in the appendix. a* Ten of "these were carried out hy Charles A* Lindbergh who in the past has made four emergency parachute jumps from pianos and a number of practice jumps from various altitudes between 350 feet and 14,000 feet* b* Two simulated jumps were carried out in the pressure chamber by John Hadden and one simulated jump each by William Pongratz and by Kenneth Hoorn of the Willow Run Bomber Plant* I c. Dr* Walter M» Boothby, Dr, Kenneth G* Wilson and Miss Ruth Knutson of the Mayo Aero Medical Unit, Dr* Charles J* Clark, flight surgeon of Willow Run Bomber Plant and Captain P* M* Thomas of Wright Field were the principal observers of the tests* d» Miss Lucille Cronin* Mrs* Ralph Cranston and Miss Rita Schmelzer were the technical aids inside the chamber and took caro of the emergencies that occurred* 2 eu Motion pictures were taken of No, *s 11, 12, 15 and 14 of tho simulated parachute jumps in tho low pressure chamber, Tho camera was placed outside tho chamber and the pictures taken through a glass port-hole. C* Development of High Altitude Emergency Oxygon Equipment As a result of simulated parachute jumps carried out in the altitude chamber, it is shown that if the jump bottle is connected to tho regular oxygen mo.sk and if a b.voak connection is placed in tho planefs oxygon lino, in tho manner to bo described., the pilot of a pursuit plane, making an emergency jump at foot and pulling his parachute rip cord immediately, will automatically obtain a sufficient supply of oxygon without any thought or action on his part* If a delayed opening descent is to bo made with this equipment., or if it is necessary for the jumper to move some distance through the piano before reaching tho point from which ho loaves, it is only neces- sary for him to pull the jump bottle, release which is attached to his flying suit or parachute harness* D* Description of High Altitude Emergency Oxygen Equipment lo Mask* The mask should be of the demand typo with a reservoir rebreathing bag around tho corrugated tubing with free intercommunicating openings, as described in Special Report No. 1 from the Mayo Aero Medical Unit to the Committee on Medical Research, O.S.R.D. 2. Harness-, Tho harness attached to tho helmet for the regular oxygen mask should bo constructed so that tho mask will stay on under all conditions encountered in leaving a plane for an emergency jump, (it is suggested that tests bo made in the wind tunnol.) 3. Jump Bottle and Valve, Tho jump bottlo con be placed either on the flying suit or the parachute harness; tho valve is connected by a cable to the parachute pull ring in such a manner that it is opened by pulling tho rip cord out a few inches farther than the distance required to release tho parachute, Tho jump bottle valve can also bo opened independently of the parachute, (New jump bottlo valve must bo designed*) 4, Break Connection, A break connection is located in the plane*s oxygen lino at the jumper*s side so that when he loaves his station the jerk on the connection automatically severs tho oscygen line; his own end being firmly attached to his flying suit. 5, Emergency Mouthpiece, A connection which can serve as an emergency mouthpiece is located about 8 inches below tho lower end of tho reservoir bag and just below a strong hook typo of fastener (see picture) so that in case tho mask is blown away, the mouthpiece will remain and can be inserted into the mouth. Distal to this connection, tho tube from the jump bottlo is inserted in the corrugated tube. This corrugated tube, loading back to the break connection, should bo about 2 feet in length and 1 inch standard minimum internal diameter. This gives a volume of about 450 c,c, which acts like a reservoir rebreathing bag as originally pointed out by Dautrobondo, As shown in tho drawing, this tube is protected by a pockot-liko flap on the flyer*s suit. 3 B. Tc/ohnic Suggested for Use of this Equipment I* Pursuit planes and plans where the Jumper leaves directly fra* his stations Jumper simply leaves plane and pulls parachute rip cord. In the case of a delayed opening Jump, he pulls the Jump bottle release at the time of leaving his plane or immediately thereafter. 2. Bombers and pianos where the Jumper must move some distance through the plane before reaching the station from which ho Jumpst Jumper simply pulls Jump bottle release before leaving his station* Nothing else is required until ho pulls his para- chute rip cord for either an immediate opening or a delayed opening descent. (However, if delay is encountered in leaving plane, it is doubtful that the Jump bottle will furnish suf- ficient oxygon for subsequent descent*) 3. In case tho jumper's mask should be blown off during the jump, an emergency mouthpiece is incorporated in the Dautpobando tube, bolov/ a point whore tho tube is clomped to tho flying suit* The oxygen tube from tho jump bottle is attached in such a manner that full advantage is taken of the Dautrebando tube effect whether tho regular oxygon mask or tho emergency mouthpiece is used* 4, An additional advantage of this equipment is that it provides an emergency oxygen system, immediately available, which can be used while the plane descends to a safe elevation in case the main oxygon system fails during flight. It is only necessary to pull the Jump bottle release to insure an adequate oxygon supply for throe or four minutes* (Obviously this loaves insufficient reserve for bailing out.) F* Conclusions 1* The tests carried on in the altitude chamber demonstrate conclu- sively that emergency bail*out oxygen equipment is essential for parachute descents from high altitude if unconsciousness accompanied by convulsions is to be avoided# 2* The tests indicate that emergency bail out oxygen equipment is desirable for all altitudes above 2( ,000 feet* 3* The tests indicate that the present now issue Jump bottle will bo adequate as a source of oxygen supply providing a quick opening valve mechanism is installed and properly designed equipment used in connection therewith. 4, The tests demonstrate conclusively that parachute Jumps from 40,000 feet con bo carried out without loss of consciousness when a regular oxygon mask with reservoir rebreathing bag is maintained in place and con- nected to a standard oxygen Jump bottle during descent. The tests show that this can be done oven after 30 seconds of heavy exercise before leaving a plane, and 10 seconds without flow of oxygen before Jump bottle valve is opened. It is extremely important, however, that the mask be retained, and that it be so firmly attached to the aviator* s head that it will not be blown off during the jump* Changing from the regular mask to a jump mask or pipestem causes loss of time in clearing the plane, requires added exertion, increases th© mental hazard, interferes with proper breathing, adds to the possibility of mechanical failure of equip-* ment, and markedly increases the danger of anoxia. 5. The tests show that in so far as it is possible, the aviator should make preparations for bailing out whilo his mask is connected to the plane*s oxygen line, and that it is advisable for him to utilize the plane*s oxygen- supply until the last possible moment before resorting to his jump bottle. The jump bottle oxygen flow, when connected to a properly designed will support considerable activity for two or three minutes at high altitudet but it i® doubtful that sufficient oxygen will remain to avoid a state of unconsciousness during a subsequent descent. 6, The tests indicate that* a. The ordinary jump bottle mouth mask or pipestem mouthpiece is inadequate to prevent unconsciousness accompanied by convulsions during an emergency parachute jump from the region of 40,000 feet if exertion is required prior to the jump. b. The ordinary jump bottle mouth mask or pipestem mouthpiece is frequently inadequate in the region of 35,000 feet if exertion is required prior to the jump or if there is delay in clearing the plane after the jump bottle has been turned on. c. That any procedure which involves the removal of the regular oxygen mask from the jumper’s face will be of doubtful success at altitudes above 35,000 feet. d. That the regular oxygen mask is preferable to mouth mask or pipestem equipment for jumping from any altitude where oxygon is needed during the descent. o. That until new equipment can be obtained for service use, and where jump mask or pipestem equipment must be used, it is advisable for the jumper to make all possible preparations for his jump before changing from his plane oxygen line and regular mask to his jump mask or mouthpiece. If a hatch is to bo opened, or if there are disconnections to be made, these items should be attended to, if possible, before the regular oxygen mask is taken off or disconnected from the plan’es oxygon line. 7. The tests show that when a separate jump mask or mouthpiece must bo used, a Dautrobonde or robreathing tube in connection therewith adds materially to the efficient use of the available oxygen, end also reduces the tendency to cough and swallow which is caused by a rapid flow of oxygon directly into, the mouth. 5 8. The tests show that: a. At least four normal breaths or three deep breaths of air can be taken by an aviator in normal conditions, at U0,000 feet, without the loss of consciousness. b, There is a delay period of approximately 20 seconds after the oxygen mask has been replaced, after breathing air, before the maximum effect of anoxia is felt. This is due to the time required for the oxygen to enter the lungs, oxygenate the blood, and reach the brain. Therefore, the aviator must realize that under similar conditions at high altitudes, even after he begins breathing oxygen again, he will be worse before he is better. c* Attention is called to the fact that, with the aviator breathing essen- tially pure oxygen, the partial pressure of the oxygen in the alveolar air at feet is about 100 ram., or practically normal, but at U0,000 feet the pressure is reduced to about SS mm* or to nearly one- half and at U2,000 feet the pressure is about US mm. or less than one- half the normal amount* Therefore, around U0,000 feet, if the oxygen is suddenly stopped, the aviator will have only approximately one-half his normal reserve supply of oxygen in his lungs (also less in his blood) and therefore will become unconscious more rapidly than at 35>,000 feet. 9* Equipment has been designed which will permit the aviator to bail out and, with a single motion, release his parachute and turn on his emergency oxygen supply. It is also possible to turn on the emergency oxygen supply prior to bailing out if a delayed opening descent is to be made or if, as in the case of bomber crews, it is necessary to cover some distance before reaching the point of exit from the plane. G. Recommendations 1, That an oxygen jump bottle with proper accessory apparatus, as here described, be a part of the personal issue equipment to all aviators going to high altitudes. 2. That flying personnel be instructed to remain on the plane’s oxygen line as long as possible before transferring to oxygen jump bottle at high altitudes. 3* That actual use of the oxygen bail out equipment in a low pressure chamber should be a part of the indoctrination program for all high altitude aviators, especially before going overseas. Prepared by Walter M, Boothby and Kenneth G, Wilson Mayo Aero Medical Unit Distribution: 20 copies to Commanding General Wright Field; 10 copies to Air Surgeon, Office, Chief of Air Forces, Washington, D, C, and Charles Aa Lindbergh & Charles J. Clark Ford Yifillow Run Bomber Plant Approved by Walter M» Boothby, D« Chairman, Mayo Aero Medical tlnit Rochester, Minnesota APPENDIX SIMULATED PARACHUTE JUMP NO. 1 September 24, 1942 M.A*M*U* Flight No, 9 Subject* Charles A. Lindbergh - Jump frcm 40,000 foot Personal Report* After 30 minutes of denitrogenization, entered large pressure chamber and ascended to 40,000 feet in 7 minutes, using nasal standard BLB mask with larger than standard rebreather bag and constant flow of oxygen. Remained at 40,000 feet or above for 1 hour and 9 minutes, includ- ing one ascent to 42,000 feet for approximately 5 minutes. Walked about and exercised mildly for larger portion of period. Bogan to notice increasing effect of altitude after about 45 minutes, possibly brought on to some degree by the ascent to 42,000 feet. At end of 1 hour, 9 minutes, removed face mask and inserted jump mask (mouthpiece in center of oro-nasal mask and 8-inch length of 3/4-inch corrugated tubing for rebreathing) in mouth* Then turned on jump valve and started exercise approximating that required to open a jammed hatch, using only oxygen flow from jump bottle* Intended to continue exercise for 1 minute, but noticed serious lack of oxygen almost immediately. Shut off re- breathing tube (Dautrebande) with one hand, to determine if oxygen flow frcm jump bottle was sufficient. An attempt to inhale demonstrated flow to be small fraction of that required to avoid inhalation of air. Attempted to continue exercise, inhaling part oxygen and part air, but realized that state of unconsciousness would soon be reached. Gave signal for descent at end of 40 seconds and sat down* Remember nothing more until consciousness returned at 25,000 feet, approximately 1 minute later* Constant flow oxygon mask had been applied during period of unconsciousness* Became alert quickly after regaining consciousness and noticed no later ill effects such as headache, ear trouble, etc* Abstract of Observers* Notes* Just before subject signalled descent it was observed that ho was very cyanotic and rapidly losing consciousness* Almost simultaneously with his signalling to descent. Miss Cronin walked across the chamber, jerked the jump mask with insufficient oxygon flow from his mouth and covered nose and mouth with an emergency mask having largo oxygen flow from chamber oxygon lino. The subject was entirely unconscious; extensive convulsive jerks of face, nock, arm and log muscles wore observed. The sub- ject gasped and after 30 seconds inhaled rather deeply and in 15 to 20 seconds more regained consciousness* No symptoms of bonds at any tine. Rat© of Flow of Jump Bottle M.A.M.V. bottle Liters Tin© STPD During 1st min* IWI 1 II1 ■■■ 3*2 ” 2nd nin* 2*7 " 3rd min* 2*3 Oral Temporaturo of Subject Time Elevation Tomp, 10,05 Ground 99©2 10,25 40,000 99,6 10,44 40,000 99*4 10,54 42,000 9904 11,06 40,000 99c4 11,24 40,000 98,6 SIMULATED PXRACHtJTB JUMP NO. 2 Soptamber-26* 1942 M.A.M.U. Flight No* 13 Subject* Charles A. Lindbergh * Jump from 40*000 feet Personal Reports After 30 minutes of donitrogenization* entered largo pressure chamber and ascended to 40*000 foot in 10 minutes? using chin bag mask and constant flow of oxygen. Remained at 4O,CO0 feet for 7 minutes,* walking about and exorcising mildly. Shut off main oxygen line to maks and -burned on jump bottle lino to mask. (Both lines wore attached to mask through a T tube and same mask was used for both ascent and jump.,) Went through 30 seconds of exercise approximating that re- quired to open a jammed hatch? then sat down during descent of chamber. Found oxygen supply to be sufficient at all times. Abstract of Observers1 Notes: Subject had only slight degree of cyanosis and was in good condition throughout descent, 7foaring mask with reservoir bag makes a tremendous difference in the appearance of the subject and makes a parachute jump at high altitude safe as far as anoxia is concerned. Rato of Flov; of Jump Bottlo (Oxygen bottle from Flight Dopt#J Willow Run Bombor Plant) Time During 1st min* Liters STPD 3*5 ii 2nd min. 3,0 it 3rd min* 2e6 n 4th min® 2.2 SIMULATES PABJLCHUTE JUMP NO. 3 Soptomber 25, 1942 M.A.M.U. Flight No* 13 Subject* Charles A* Lindbergh - Jump from 35,000 feet Personal Report* Remained on oxygen mask for about 20 minutes while waiting for new oxygen emergency bottle to be brought in through lock at about 4,000 feet* This new bottle was the recent issue type and had a higher rate of oxygen flow and was outfitted with standard type wood mouthpiece; an emergency T connection to chamber oxygen line was added for safety* Then ascended to 35,000 feet in 5 minutes, using same chin bag masrc as on previous ascent and constant flow oxygen. Remained at 35,000 feot for 30 seconds* Then turned on jump bottle, removed mask and inserted wood morsApiece between teeth, keeping lips closed around mouthpiece* Went through 30 seconds of exercise approximating that re- quire* to epen a jammed hatch, using only oxygon flow from jump bottle; then sat down and began descent at rate of 3,000 feot per minute, de- creasing descent rate after first minute. Flew from bottle too high for comfortable breathing so decreased it by partially closing jump bottle valvea Drying effect of high oxygen flow in mouth and throat caused tendency to cough. Removed mouthpiece at 26,000 feet and con- tinued to ground level without oxygen* Abstract of Observers* Notes* At first the rate of flow was obviously excessive. However, the subject descended without serious difficulty0 It must be remembered that at 35,000 feet the subject starts with nearly normal oxygen in the lungs, and therefore has nearly twice as much reserve in his alveoli than if ho were at 40,000 feet. Rato of Flow of Jump Bottle Issue boitlo Time Liters STPD During 1st min. 6.3 n 2nd min* 5,3 n 3rd min. 4.4 >i 4th min. 3,8 if 5th min. 3,2 n 6th min. 2,6 SIMULATED PARACHUTE JUMP NO, 4 September 1942 MJUM-U, Eligtvt No- 14 Subject* Charles A, Lindbergh - Jump from 40,000 feet Personal Reports After 30 minutes of denitrogonization, entered large pressure chamber and ascended to 40,000 feet in 7 minutes, using chin bag mask and constant flow of oxygon. Remained at 40,000 feet for 10 minutes.-, exorcising mildly during part of time. Turned on jump bottle, removed mask* inserted standard typo wood mouthpiece between teothp and carried on 30 seconds of heavy exorcise on jump bottle flow alone, then sat down* Noticed serious lack of oxygen within few seconds. Turned on additional oxygen from chamber oxygen line (which was con- nected to jump bottle mouthpiece through a T tube) to avoid becoming unconscious, Flow of oxygon from standard type of jump bottle wood mouth- piece is odd and dry, and causes tendency to cough and swallow. Abstract of Observers* Notes; Subject rapidly became cyanotic and was obviously very near unconsciousness Just before he turned on chamber oxygon-, For several breaths after the oxygon was turned on, subject became worse and almost passed out but after about 20 seconds ho started to improve rapidly. Delayed action of ©aygon was due to time needed to fill lungs with oxygon and for the oxygenated blood to get to the hoado Rate of Flow of Jump Bottle (Standard issue battle*} Liters Time STPD During 1st min. 6,3 n 2nd min. 5.3 n 3rd min. 4.4 jump no* 5 Soytoabor 26* 1942 M.A.M.U* Plight No* 14 Subject: Charles A. Lindbergh - Jump from 35,000 feet. Note*. This jump made on same flight in chamber as previous jump* Personal Report: After descending to altitude of 25*000 foot, rested and roascondod to 35,0©0 foot in 5 minutes, using A-8-B oxygon mask and constant flow oxygon* Remained at 35,000 foot for 8 minutes, exorcising mildly at intervals. Turned on jump bottlo valve, romovod oxygen mask, placed pipostom type wood mouthpiece between tooth, and carried on 30 seconds of heavy exorcise on jump bottle flow alone* then sat down» Felt need of additional oxygon for some seconds but was able to retain consciousness and continue descent without turning on chamber oxygen valve, (A T tube., connected to the chamber oxygen line had boon placed in the jump bottlo lino for emergency use.) Removed jump bottlo mouthpiece at 23,000 foot and found no difficulty in continuing descent without oxygen. Abstract of Observers1 Notes: Subject became cyanotic and it was suggested that the additional oxygon from the chamber lino bo turned on; however, it was decided to wait a few seconds longer. Then as ho started to improve it was recognized that ho would not become unconscious* However, it was a very close shave* Rato of Flow of Jump Bottlo (Oxygon bottlo from Flight Dopi,* Willow Run Bomber Plant) Tlmo Liters STPD During 1st min. 3.5 » 2nd min* 3.0 it 3rd min. 2,6 n 4th min. 2,2 SUHJUJED- PARACHUTE jump no* 6 September 269 1942 M.A*M*U* Flight No* 14 Subject* William Hadden - Jumps from 35,000 feet Report made by Dr. C, J, Clark* Subject entered chamber after 30 minutes nitrogen desaturation program. Oxygen supply through constant flew* chin bag mask, rate of flow 42,000 feet, active, ascended to 40,*000 feet in 7 minutes. Remained at 40«000 feet for 11 minutos6 it 7th min. 2,3 it 8th min. 1,6 11 9th min. 1*6 it 10th min. 1.4 SIMULATED PARACHUTE JUMP NO, 11 September 28, 1942 M#A#M*U# Flight No0 18 Subjects Charles A# Lindbergh - Jump from 40,000 feet# Personal Report* After 30 minutes of denitrogenization, entered largo pressure chamber and ascended to 40,000 foot in 7 minutes, using Bulbulian demand typo mask with robroathor bag*, Doutrobando tube, and jump bottle tubo attached noar tip of Dautrobando tube# Used constant flow of oxygon for ascent# Remained at 40 ?000 feet for 10 minutesc Then carried on 30 seconds of exercise, lifting steel cylinder (simu- lating effort required to open jammed hatch and jump out of plane — amounting to 486 foot pounds in 30 seconds*) Then broke connection attaching mask to chamber oxygon lino* (Hero, chamber started descend- ing at parachute rate.) Remained without ary flow of oxygon to mask for 10 seconds (simulating time required to pull parachute rip cord)* Then pulled parachute rip cord, thereby opening jump bottle valve and starting flow of oxygon from jump bottle to mask* Chamber continued to descend at parachute rate to 20,000 foot# Then reconnected oxygon mask to chamber oxygon line to prepare for next ascent. Noticed no serious lack of oxygon at any time# Abstract of Observers* Notes* During jump subject had perfect color and the bag on the mask did not fully collapse so that he would bo getting practically 100 per cent oxygon. Condition excellent* SIMULATED PARACHUTE JUMP NO* 12 September 28, 1942 M.A*M.U* Flight No. 19 Subject* Charles A, Lindbergh - Jump from 35,000 feet. Personal Report* Remained on oxygon mask at ground level for several minutes after Flight No* 11 until oxygen bottle was refilled. Then ascended to 35,000 foot in 5.5 minutes, using same mask ns on previous ascent and constant flow of oxygon. Remained at foot for 5*5 minutes* Then carried on exorcise for 30 seconds, lifting stool cylinder — 459 foot pounds in 30 seconds0 Thon broke connection attach- ing mask to chamber oxygon line and removed face mask© Chamber started descending at parachute rate. Had intended to remain without oxygon for 15 seconds, but error in timing increased this period to 35 seconds, Thon pulled parachute rip cord which should have opened jump bottle valve, but valve was excessively tight and did not open. Failed to notice this and attempted to obtain oxygon through emergency mouthpiece* Soon realized that unconsciousness was approaching and hold chamber emergency mask to face. (Mask with high oxygon flow was kept at hand for such an emergency.) Signaled for chamber to bo dropped rapidly. Reached the verge of uncon- sciousness, thon, as oxygon entered circulation, senses returned rapidly to approximately normal condition. Dropped chamber to 20,000 feet? and held at that altitude for 10 minutes in preparation for another attempt. Abstract of Observers1 Notes* This illustrates precautions needed to prevent serious accident when confusion or mistake in experi- mental procedure develops* SIMULATED PARACHUTE JUMP NO* 13 September 28, 1942 M*A«M*U# Flight No, 19 Subject* Charles A. Lindbergh - Jump from feet. Personal Report* After 10 minutes breathing oxygen at 20,000 feet, reascended to 35,000 feet in 2,5 minutes, using same mask as on first asoent and constant flow of oxygen. Remained at feet for 6,5 minutes. (Condition not as good as on Jumps No, 11 and 12.) Then carried on exercise for 30 seconds, lifting steel cylinder, (432 foot lbs, in 23 seconds,) Then broke connection, attaching mask to chamber oxygon line, and removed face mask® Chamber started descending at para- chute rate. Remained without oxygen for 15 seconds. Then pulled para- chute rip cord, thereby opening jump bottle valve. Detached emergency mouthpiece from fitting and began breathing oxygen from jump bottle. Found that in addition to its increased oxygen efficiency, the Dautrebonde tube greatly reduced the tendency to cough and swallow which was caused by the regular pipestem typo mouthpiece. Noticed lack of oxygen at 32*000 feet, but was able to continue descent at parachute rate and condition soon began to improve. Removed mouthpiece at 25,000 feet and discontinued breathing oxygen until 15r000 foot level was reached. Then went back on oxygon to avoid "hangover.” Abstract of Observers* Report* Color was very poor throughout the jump. Apparently the fatigue of previous jumps made it much harder for subject to carry on® Rate of Flow of Jump Eottle (issue bottle) Tim© Liters STPD During 1st min. 603 it 2nd min. 5,3 it 3rd min. 4.4 it 4th min. 3,8 ti 5th min. 3,2 n 6th min. 2C6 «t 7th min. 2,3 n 8th min. 1*6 n 9th min. 106 n 10th min. 1«4 it 11th min. 1*2 H 12th min* loO If 13th min® 0C81 11 14th min. 0*70 SIMULATED PARACHUTE JIMP NO. 14 September 29* 1942 M.A.M.U. Flight No* 20 Subject* Charles A. Lindbergh - Jump frcm 35,000 feet® Personal Reports After 30 minutes of donitrogenization, entered largo pressure chamber and ascended to 35,000 feet in 5 minutes, using Bulbulion demand typo mask with rebreather bag, Dautrebande tube, and jump bottle tube attached near tip of Dautrebande tube. Used constant flow of oxygen for ascent. Remained at 35,000 feet for 10 minutos0 Then carried on 30 seconds of exercise, on chamber oxygon line, lifting steel cylinder (459 foot pounds work in 30 seconds). Then broke connec- tion attaching mask to chamber oxygon lino and removed mask from face (to simulate mask being blown away during jumpju Chamber started descend- ing at parachute rate. Remained without oxygen.for 20 seconds. Then pulled parachute rip cord, thereby opening jump bottle valve. Detached emergency mouthpiece from fitting and began breathing oxygen from jump bottle. Chamber continued to descend at parachute rate. Removed mouth- piece at 25,000 foot and discontinued breathing oxygon entirely until 15,000 foot level was reached. Then wont back bn oxygon to avoid ”hang- ovor.” adequate oxygon reserve throughout entire jump. Abstract of Observers» Notes* The set up used in this experiment was made with the finally perfected apparatus and had a larger Dautrebande tube for robreathing. This sot up is very much better than previous ones both for oxygon efficiency and for ease and safety in use. Rato of Flovi of Jump Bottle (issue bottle) Timo Liters STPD During 1st min* 6,3 n 2nd min* 5«3 n 3rd min. 4*4 it 4th min. 3*8 n 6th min. 3e2 SPECIAL EXPERIMENT No* 1 September 27, 1942 M*A*M*U. Flight No, 16 Subject* Charles A, Lindbergh - Alveolar Airs at 35,000 and 40,000 feet. Abstract of Observers* Report* Subject was donitrogonized for 30 minutes and then* 1* Ascended in chamber to 35#000 foot in 7 minutes# wearing A-8-B mask with oxygen flow set at 35tO000 foot ond after about 6 minutes at sitting rost gavo first alveolar air© 2* Oxygon flow was increased to 35,000 feet active and subject exorcised and gave second alveolar air© 3p Chamber was raised to 40,000 foet in <2 minutes# and after 5 minutes third alveolar air sample taken with oxygen flow at 40#000 foot inactive* 4* Oxygon flow increased to 40,000 feet active and subject oxorcisod and gavo fourth alveolar air# ALVEOLAR AIR Elevation Subject 0j> Flow set at CO 2 % mm. °2 % » mm. 35,000 Inactive 35,000 inactive 24c69 33 72c67 96 35,000 Active, doing about 2,000 ft, lb, work in the minute, end- ing about minute before the alveolar air* 35,000 active 24© 25 32 70,29 93 40,000 Inactive 40,000 inactive 23052 32 63,66 60 40,000 Active, doing about 1,000 ft, lb, work in next to last half minute before alveo- lar air© 40,000 Motive 33,23 31 65,41 61 It is to bo noted that the oxygon pressure in all four alveolar airs was exactly at the theoretically perfect level# SPECIAL EXPERIMENT NO, 2 September 27, 1942 M.A.M.U, Flight No, 16 Subject* Charles A# Lindborgh •» Effect of breathing air at 40,000 feet. Personal Report* After 30 minutes of donitrogonization, entered large pressure chamber and ascended to 40,000 foot in 18 minutes, using A-8-B oxygon mask and constant flow of oxygen. Alveolar air samples wore taken at 35,000 and 40,000 feet, (See Special Experiment No© l) W, Je Hadden carried on simulated parachute jump (See Jump No® 9) from 40,000 feet during which the chamber dropped to 30,000 foot, Reascondod to 40,000 foot. 1* Removed mask and took 1 normal broath of air in chamber, then roplacod mask; noticed no effect© 2* Two minutos later, romovod mask and took 2 normal broaths; noticed slight effect, starting several seconds after re- placing oxygon mask* 3* Two minutos later romovod mask and took 3 normal broaths; noticed definite effect starting several seconds after replacing oxygon mask and increasing for several seconds thereafter® 4* Throe minutes later removed mask and took 4 normal broaths; noticed strong effect, starting several seconds after re- placing oxygon mask and increasing for several seconds there- after* 5* Three minutos later, romovod mask and took 1 deep broath of air in chamber; noticed slight effect, starting several seconds after replacing oxygen mask© 6* Three minutos later, removed mask and took 3 deep broaths; noticed doffinife? effect starting several seconds after replacing oxygon mask and increasing for several seconds thereafter* 7* Throe minutes later, removed mask and took 3 dopp breaths; noticed strong effect starting several seconds after replacing oxygon mask and increasing for several seconds thereafter© The fact that the subject continued to got worse after putting the oxygon mask back on, in every instance, is important for the eviator to remember. If for ary reason the aviator!s oxygen is cut off at high altitude, ho will progressively and rapidly become anoxic; he will con- tinue to got worse and may become unconscious for a few seconds before ho starts to improve, oven after the oxygen is again started, because, as wo discussed with Dr, Boothby, it takes some time to rebuild the oxygon pressure in the alveolar air "nd for the rooxygonatod blood to got to the central nervous system. The lag seems to be about 15 to 20 seconds© PRESSURE CHANGES IN BLB CHIN TYPE MASK AT REST AND AT W0RK(1200 ft.lbs./min.) AT VARIOUS SIMULATED ALTITUDES. IN THE mv PRESSURE WAmvn Pressure in cm. of water RESTING WORKING FLOW - 0.8 L/min. - 15,000 Inactive FL0W - 1,6 L/min. - 15,000 Active ALTITUDE - 15,000 feet Umjo A*ro-W«dioal Unit Booifcby, Fllan and Bra it M»y 15, 1942 Pressure in cm. of water RESTING WORKING FLOW- 1.1 L/min. - 20,000 Inactive FLCW - 2,1 L/min - 20,000 Active ALTITUDE - 20,000 feet Mayo A«ro-UedioiX Halt Soathfcy, Fllnn and Brait May 19. 1942 RESTING WORKING FLCW - 1,4 L/min - 25,000 Inactive FLOW - 2,9 I/min - 25,000 Active ALTITUDE • 25,000 feet Pressure in cm. of vmter FLOW -1.8 I/min - 30,000 Inactive RESTING FLOW -3.6 I/min • 30,000 Active WORKING ALTITUDE - 30,000 feet Mayo Aero-Medloal Unit Boothby, Fllnn and Bratt May 15, 1942 Pressure in cm. of v:ater RESTING WORKING FLOW - 2.2 L/min - 35,000 Inactive FLOW - 4.4 L/min - 35,000 Active ALTITUDE - 35,000 feet Pressure in cm, of water FLOW - 2,5 L/min - 40,000 Inactive RESTING FLOW - 5,0 L/min - 40,000 Active WORKING- ALTITUDE • 40,000 feet MAYO AERO—MEDICA1 UNIT ROCHESTER, MINN u © ■p 03 * v< 0 1 © u a V) w O It cm RESTING WORKING( 1200 ft. Ibs/min. ALTITUDE - 15000 Feet Pressure in om* of water RESTING RESTING (AUTOMATIC REGULATOR TURNED OFF) WORKING ( 1200 ft. lbs/ min) JUNE 3, 1942 ALTITUDE - 25000 Feet BLB DEMAND ARMY AUTOMATIC REGULATOR TYPE A-12 SERIAL 127 ARO EQUIPMENT CORPORATION XY- 2 * MAYO AERO-MEDICAL UNIT ROCHESTER MINN. Pressure in cm, of water WORKING ( 1200 ft lbs/ min) RESTING ALTITUDE - 30000 Peet Pressure in cm of water RESTING ALTITUDE « 33000 Ptet WORKING 1200 ft* lb«/ win) JUNE 9, 104f J58MAND ARMY AUTOMATIC REGULATOR TYPE A-12 SERIAL X27 ARO EQUIPMENT CORPORATION b MAYO AERO - MEDICAL UNIT ROCHESTER, MINN RESTING WORKING (1200 ft lbs/ min) ALTITUDE - 40000 Feet JUNE 3, 1942 BLB DEMAND ARMY AUTOMATIC REGULATOR TYPE A-12 SERIAL 127 ARO EQUIPMENT CORPORATION XV- 2 c MAYO AERO MEDICAL UNIT MEMORANDUM REPORT tc ARMY AIR FORCES MATERIEL COMMAND Under Contract No, W535ao-28529 SUBJECTS Report on positive pressure breathing (a) constant pressure and (b) pulsating pressure (chest compression up to 4 cm* Hg for short periods 3 to 4 times during expiration) by Boothby and Lindbergh* SERIAL REPORT* Series A, No. la DATE* October 3, 1942 A. Purposes. 1. To determine the effect of positive pressure breathing on ability to go to high altitudes* 2* To determine whether or not a pulsating or rhythmic type of pulsat- ing breathing has an added advantage* B. Factual Data. The details of the experiments conducted on producing pulsating breath- ing on Col, C, A. Lindbergh are given in the appendix© a, Experiment No* 1, October 1* 1942, in the individual low pressure chamber. An altitude of 36,000 to.42,000 was maintained for 3 hours and 27 minutes using new typo pulsating pressure breathing (short compressions of chest against increasing manometer to 4 cm, Hg), b* Experiment No* 2, October 2, 1942, in the large low pressure chamber* An altitude of 30,000 feet was maintained for 2 hours and 27 minutes and 40,000 feet for 43 minutes. Alveolar airs were obtained at 30.000 feet and 40,000 feet, o* Experiment No, 3 in the large low pressure chamber. An altitude of 40.000 to 45,000 feet was maintained for 16 minutes and stayed at 45.000 feet for 6 minutess C. Conclusions* Positive pressure breathing experiments were conducted on Col, C, A, Lindbergh, Some were done with constant pressure apparatus consisting of a weighted spirometer. Those on Col, Lindbergh were carried out by stopping up one sponge rubber disc on constant flow mask and producing pulsating type of flow by closing and opening the other sponge rubber disc with hand0 The latter seemed to gain some improvement in general condition at altitudes above 40,000 feet and Col, Lindbergh thought it could be of some help for short time in an emergency* Prepared by Walter M, Boothby, M,D* Chairman Mayo Aero Medical Unit EXPERIMENT NO# 1 October 1, 1942, Mayo Aero Medical Unit Qjd man chamber Controlled either inside by subject or outside by observer* Subject: Col# C# A* Lindbergh wearing nasal BLB with 2 sponge rubber discs# Time Elova- 0£ flow Body temperature Remarks tion no ex- ercise after exercise llc09 Ground 98.5 98.3 lie 24 40,000 55 aot. 11*26 40,000 35 act. 98.4 11*35 40,000 35 act. Color good 11*40 n it 98.5 11.41 n i» 25 minutes above 30,000 ft, and 17 minutes at 40,000 ft. 11.50 n n 98.3 Color good 12.00 39,000 n Chamber dropping although valves all closed (pump too warm) 12,05 38,400 n 98.4 At 40,000 ft, for 41 minutes 12.08 38,000 it 12,10 37,-500 it 98.6 12.12 37,000 Chamber still dropping 12.15 37,500 30,000; act. Chamber all right now 12.20 37,500 30,000 98.5 12.24 37,000 30,000 37,000 to 40,000 ft, for 1 hour. 12-26 36,800 30,000 Pressure dropping again 12.30 36,400 38,000 act. 98,5 12.35 36,800 38,000 Climbing again slowly. Water cooler was half empty, Ice cubes put in water also. 12.36 37,600 40,000 act. Pressure all right now. 12.38 38,000 40,000 act. 12.40 38,500 40,000 act. 98.5 1.10 40,000 41., 000 act. 98.2 1c 20 40,000 41,000 act. 98.1 1.24 40,000 it 2 hours above 36,000 ft. 1.30 40,300 ii 98,3 lc35 40,200 98.3 lo50 it ii 98,3 2.00 40,000 35,000 act. 98.7 Col, Lindbergh has been trying a new kind of breathing. He has held each breath and compressed chest 2 or 3 times intermittently in attempt to produce a positive 03 pressure in lungs* He feels this might be helpful to a lone aviator who felt he was not getting enough 0? at high altitudes (40*000 or above). 2.07 40,000 35^000 act. 2*09 42,000 it Will try positive pressure breathing. 2,16 40,000 Says he could notice an improvement 5ft the way he felt and would like to try it at 44*000 ft. Will try this in large chamber only. 2.20 ii ii 98.8 Experiment No* 1 (continued) Time Eleva*' 02 flow Body temperature Remarks tion no ex- ercise after exercise 2*24 40,000 35,000 net* 3 hours above 36,000 ft. Still using positive pressure breathing. Color entirely normal and feels good. Checking pressure exerted with each compression on mercury manometer inside. Is using 4 cm, mercury pressure with each corn- pressure and is doing 3 compressions with each inspiration* 2*07 ir n 98.8 Col* Lindbergh says he definitely feels much better today at 40*000 ft, after being here over 3 hours than he did the other day after 1 hour and 10 minutes at 40*000 ft® 2,43 n n 98,9 2,44 it »i Pulse 96 2,45 n n Check on pulse 96 2*5C ti ti 98,9 3 hours and 25 minutes above 36*000 ft. 2.51 Start down 2,52 Ground — Down from 40,000 ft* to ground in 1 minute and 30 seconds. October 2, 1942, Mayo Aero Medical Unit Large low pressure chamber Flight No* 21 Subject; Col* C* A. Lindbergh Wearing nasal BLB constant flow,, Decompressed for 31 minutes,, Observer* Henrietta Cranston Wearing nasal BLB constant flow* Decompressed for 2o minutes0 Observer; Rita Sohmelzer Wearing A*8~BC Decompressed for 20 minuses? Air l * 34 4 » ft 61*16 0 4# ft 67 4 0 Grad© II cyanosis. Now breathing naturally 3.42 it « 0 «0 • c e • 4 4 4 o H.C. thinks C*A0L,is starting to 3*46 n n •> 4 « O 0 4 4 0 4 O 0 4 get better Respirations 12/min. 3.48 n it 3C48 n n *04 ft ft 4 4 4 4 ft rt 4 now Gr. I Hands over both sponge rubber disk 3.50 it n 0 0 4 O ft 4 0 0 4 « O ft Color seems better -also marked 3,51 n n 4 ♦ . V> ft ft ft 4 4 o 0 4 change in colrr almtncrnal Now breathing through 2 sponge 3.62 n n C ft rubber disks(releasing pressure) Becoming more cyanotic 3*52 M n 0 4 ft ft 4 ft ft 0 ft 4 C 6 1 pulsation per breath 3*53 II n 0 0 4 e 4 4 COO 0 4 ft Definitely worse 3*54 n ti ft 0 4 ft 4 4 0 ft 4 0 ft 4 Lips and nails blue 3.56 n n OO. 0 4 e 0 4 4 c 0 *> Lindbergh doing something dif :e rent Experiment No. 2 (continued) Tim© Elevation Og flow co2$ mm. 0g% mm, Remarks 3,58 Start down From 40*000 - free fall to ground In min. and 12 sec. He tried to create a slight Negative pressure but it did not work 43 min, 40*000 ft. October 3, 1942, Mayo Aero Medioal Unit Flight No. 22 Subjecti Lucille Cronin Wearing A-8-B mask and positive pressure apparatus (consisting of a weighted spirometer) Observer* C.A. Lindbergh Wearing the chin bag type mask, constant flow. Mask has 2 sponge rubber disks but one of them was re- placed with a cork. To try pulsating breathing and observe L.Cronin on clinical positive pressure apporatr Observer* Rita Sohmelzer Wearing A-8-B mask, in airilock. EXPERIMENT NO. 3 Time Elevation Remarks 10*55 Start up Lucille Cronin on positive pressure apparatus. 10,58 14,500 ft. Oxygen flow beyond reading on flow meter. Dead space in mask expanding so have to out a hole in the mask. 11.05 25,000 ft. StiU easy to breathe. 11,10 40,000 ft. Feels all right. 11.15 42,000 ft. Subject does not look comfortable. 11.17 42,000 ft. Subject does not notice much difference between 40,000 and 42,000 ft, as on other runs. U,2l 44,000 ft. Color just as good as when at ground. Mask very uncomfortable-. 11,23 45,000 ft. Not as comfortable as at 42,000 ft, but feels all right. 11,24 40,000 ft. 11,26 45,000 ft. Subject feels as good at 43,000 ft, as at 40,000 ft, with regular mask. Feels better at 45,000 ft, than first time at 45,000 ft. 11,28 45,000 ft. Lindbergh holding other port on mask - good reaction. 11.29 45,000 ft. Lindbergh looks better. Subject is pulsating port with thumb. Better without pulsation. 11.29 45,000 ft. Subject Lucille Cronin color all right. MAYO AERO MEDICAL UNIT MEMORANDUM REPORT to ARMY AIR FORCES MATERIEL COMMAND Under Contract No. W5>3£ac-25829 SUBJECT: Indoctrination of 21 crews of the Bombardment Group SERIAL REPORT: Series A, No. 2. DATE: October 30, 19U2 A . Purposes: Through arrangements made by General Olds and Colonel Matheny and with the help of Colonel Benson of the Aero Medical Research Laboratory, Wright Field* the Mayo Aero Medical Unit carried out an indoctrination of 203 men of the 307th Bombardment Grcup in the use of oxygen and in the general physiology of high altitude flying including the methods of decreasing the danger from bends 3e Factual Data: 1, 21 crews 203 officers and men Uii crew flights 23 men incapacitated by bends - - = 11$ 20 flights jeopardized by bends - s U6$ 2h flights not jeopardized by bends= 5>U$ 24 The officers and enlisted men came in units of one complete crew from the Souix Oity Air Base to Rochester for instruction in the low pressure chamber. Forty- four brew flights were made which gave a total of 380 man flights to 35jOOO feet or over. Four crews made 3 flights each, 16 crews made 2 flights and 1 crew made 1 flight4 Sixteen of these flights lasted 3 hours. Hi flights hours, 3 flights 2 hours, 7 'flights If hours and U flights 1 hour. 3# Twenty-three men were incapacitated by the bends and had to be taken down in the air-lock. This is a comparatively small number, only 11$. The details are given in the summarized individual flight reports attached herewith. A new point, however, which has not been brought out before is the distribution throughout the crews of these men who were incapacitated by bends. It was found that out of the hh crew flights the mission in 20, or U6$, of the flights was seriously jeopardized by at least one man becoming incapacitated. This left only 2h, oir 5>U$, the flights in which there was no serious interference with the missions from individuals becoming incapacitated from the bends. lu Time was not available for testing the men with and without denitrogenation. However, in several instances we were able to show the individual men who had the bends that they had less difficulty if they were denitrogenized. This part of the data, however, is too meagre to refer to in direct numbers or to attempt to work out in percentages. 2 5# At lectures and during the indoctrination runs emphasis was placed on the practical management of their oxygen equipment and the necessity of each aviator watching his "life-line’1 and oxygen supply* Also each individual member of the crew was instructed in the procedures to be carried out if another member of the crew should have difficulty* It was pointed out that at 35,000 feet, if the subject was working, there is hardly more than 35 seconds before the subject becomes uncon- scious if the oxygen supply fails and a lesser time at U0,000 feet. With the aviator inactive, it vrould take nearly twice as long for the subject to become un- conscious o 6. One flight was taken to UU,300 feet, U to iiij.,000, 6 to h3,000, U to U2,*000, 1 to Ul,500, 17 to U0,000, 1 to 39,000, 1 to 38,000 and 9 to 35,000 feet. The experience of gring to high elevations is valuable as it gives the aviator confidence in his equipment if he is adequately trained in its care and usej he realized that his ceiling so far as anoxia is concerned is definitely above U0,000 feet. 7. Method of bailing out was illustrated by movies. 8. The above indoctrination course was rendered possible by the enthusiastic cooperation of the staff of the Mayo Aero Medical Unit consisting of Drs. Wilson, Robinson, Cunningham, Code and Wood, Mr. Bratt, Miss Knutson, MKas Cronin, Mrs, Cranston, Mrs. Larson, Miss Campion and Miss We inhold. Prepared by: Walter M, Boothby, M,D. Chairman, Mayo Aero Medical Unit Rochester, Minnesota MAMU FLIGHT NO. 23 Monday, October 5, 19h2, from 2:12 P. M» to £;08 P, M. (2°56») Squadron 370, Crew 1, Flight A 1# Pilot Capt* L. F, Krebs Decompression None Mask A^B 2. Co-Pilot 1st Lt. J. Nowell None A-8-B 3. Bombardier 2nd Lt* J* D. Newman None A-8-B h. Tail Gunner Sgt* E. F. Gartland None A-8-B 5. Radio Operator S/Sgt. A. S. Hatfield None A-8-B 6. Engineer Sgt. M. E. Hatfield None A-8-B 7. Asst. Engineer S/Sgt* R. N, Furtwangler None A-8-B 8. Asst. Open. Off* 2nd Lt. K. M. Kidder None A-8-B 9. Extra Pvt. M. Casoria None A-8-B Condensed Log of Flight Duration Elevations IlrSc Min# Highest Elevation U0,000 ft# 52 30,000 - feet 1 27 35,000 - 39,000 feet 6 feet Total, 2 hr. 25 over 30,000 feet Results Bombardier, Newman Ul min. 35,000 - U0,000 feet Developed pain right ankle (35,000). h2 " 35,000 - i;0,000 " Pain better. 58 11 35,000 - U0,000 « Pain very bad. 1 hr. 1 n 35,000 - h0,000 M Pain so severe he entered air lock and was taken to ground. Nose bleed in air lock. 9. Asst. Oper. Off., Kidder 53 min# i%,660 feet Slight pain in knees but not incapacitating. Navigator - Had cold so did not take the flight. The other seven men had no symptoms. Summary: Bombardier incapacitated in 55 minutes at 35*000 feet and to this extent jeopardizing the object of the mission. MAMU FLIGHT NO* 2U Monday, October 5, 19U2, from 705 to 9*12 (l037*) Squadron 370, Crew 1, Flight A Decompression Mask 1. Pilot Capt. L. F. Krebs 21 min. exercycle Drinker 2. Co-Pilot 1st Lt. J. Nowell 22 min« 3 mi./hr. A-8-B 3. Bombardier 2nd Lt. J. D. Newman 27 rain0 3 mi./hr. A-8-B U. Tail Gunner Sgt. E, F. Gartland 1U min. ball A-8-B 5>. Radio Operator S/Sgt. A. S. Hatfield None A-8-B 6• Engineer Sgt. M. E, Hatfield 1$ min. 3 mi./hr. A-8-B ?• Asst. Engineer S/Sgt. R. N. Furtwangler None A-8-B 8. Asst. Oper. Off. 2nd Lt. K. M. Kidder 19 min. 3 mi./hr. Drinker 9. Extra Pvt. M. Casoria None A-8-B Duration Hrse Min. Elevations Highest elevation UU,000 feet. 17 30,000 - 3U,000 feet U6 35,000 - 39,000 feet 2 i*0,000 - Ul,000 feet 3 over U2,000 feet l 8 over 30,000 feet Condensed Log of Flight Results 1. Pilot, Krebs 3U min* 35,000 feet Slight pain at knee* h9 min* 35,000 feet Pain gone* 2* Co-Pilot, Nowell U2,000 feet Choky feeling. 3* Bombardier, Newman 20 min. 25,000 feet Nose bleed. Pain at knee 2h min, 35,000 feet Pain at knee worse* 26 rain* 35,000 feet Went down in air lock* 6* Engineer, A, S. Hatfield i±2,000 feet Pain over right eye. The other five men had no symptoms. Summary: Bombardier in this flight was forced down by pain in a shorter time than yesterday in spite of decompression* MAMU FLIGHT NO. 25 Tuesday, October 6,' from 9:25 to 11:29 AM (2°5’) Squadron 370, Crew 1, Flight A 1. Pilot Capt. L, F, Krebs Decompression l£ min. 3 mi./hr. Mask T&b 2. Co-Pilot 1st Lt. J, Nowell None A-8-B 3. Bombardier 2nd Lt. J. D. Newman 30 min. 3 mi./hr. A-8-B h. Tail Gunner Sgt* E. F, Gartland None A-8-B 5. Radio Operator S/Sgt, A, S. Hatfield None A-8-B 6. Engineer Sgt. M. E. Hatfield None A-8-B 7* Asst. Engineer S/Sgt, R. N. Furtwangler None A-8-B 8. Asst, Oper, Off. 2nd Lt. K. M, Kidder None A-8-B 9« Extra Pvt. M. Casoria None A-8-B Condensed Log of Flight Duration Llevations Highest elevation 38,000 feet Ilrsc Idn* u 30,000 - 3h,000 feet . U3 35,000 - 38,000 feet 1*8 Over 30,000 feet Results 7* Asst. Engineer, Furtwangler 3U min. 36,000 feet Pain in right foot. 9• Extra, Casoria 19 min. 35,000 feet Pain in left arm. 30,000 n Better. 5 n 38,000 M Slight pain left elbow. 18 ” 38,000 11 Pain in elbow and fingers left hand. The other seven men had no symptoms. 3* Bombardier, Newman, who had to come down in both previous runs not affected this time, probably because decompression was more efficiently carried out. Summary: No interference with mission from bends. Tuesday, Squadron 371, Crew 1 October 6, 19U2, from 1:50 , Flight A p.m. to ln£3 p*m. (3°3') 1» Pilot Capt. E, T. Lippincott t)e compress ion None Mask A^B 2. Pilot Capt. C, J, Lamothe None A-8-B Rebr. 3. Co-Pilot 2nd Lt, S, E, Schreiber None Demand Rebr. Navigator Capt. C. G. Benes None B* Demand 5. Tail Gunner Sgt. P. C. Williams None A-8-B 6. Tail Gunner Sgt. D. Carpenter None A-8-B ?• Radio Operator Sgt. J* G, Pope None A-8-B 8, Engineer Sgt. H. W, Dumas None A-8-B 9, Asst* Engineer Sgt. R. E. Jamason None A-8-B MAMU FLIGHT NO* 26 Duration Condensed Log of Flight Hrso Min. Elevations Highest elevation U0,000 feet — T 30,000 - 3U,000 feet 2 19 35,000 - 39,000 feet 7 U0,000 feet t-3- 000 feet 9 ” 20-30,000 33 " 35-39,000 Pain in left knee (39,000). 12 n Pain better and no further trouble, even at kU,000 feet, 7, Engineer, Pumas lo min, 35-12,000 Pain in left arm gr. II at U2,000 Came down 35,000 No better B ,r 30,000 Somewhat betterj dizzy, M n 25,000 Very dizzy 35 min, after beginning flight came down in air-lock. The other six men had no symptoms. Summary: Mission interfered iffith by incapacity of Engineer ii&vflJ FLIGHT NO. 28 Wednesday, October 7, 19h2, from 9:51 a.m. to 12:56 p.m. (3°5*) Squadron 371, Crew 1, Flight A Decompression Mask 1. Pilot Capt« E, T. Lippincott None a-8-b 2, Pilot Capt. C. J. Lamothe None Be Demand Rebr. 3» Co-Pilot 2nd Lt. S, E* Schreiber None A-8-B lu Tail Gunner Sgt. D. Carpenter None A-8-B Tail Gunner Sgte P. C. Williams None A-8-B 6. Engineer Sgt, H. W. Dumas None ?«, Asst. Engineer Sgto R. E, Jamason 30 min* 3 mi./hr* A-8-B Duration Elevations Highest elevation 35*000 feet. HrSo Min. 36 30,000 - 3U,000 feet 2 6 35,000 - 39,000 feet CM ~=t CM over 36,000 feet * Condensed Log of Flight Results lo Pilot, Lippincott U8 rain. 35,000 feet Pain in shoulder, wrist, left leg and foot* $9 11 35,000 11 Pain about the same* 1 hr* 30 11 35,000 ” Took 8 breaths with mask off to test effect of anoxia* Took mask off again for 10 quick breaths after a few minutes* Felt severe kick* 1 n 32 11 35,000 w Pains worse, probably result of the anoxia due to testing* Came down in air-lock* 2* Pilot, Lamothe 1 hr. S6 min* 35,000 feet Pain left leg, kneb and ankle; uncomfortable* 2 n U ” 35,000 n Pains better relieved by a temporary lowering of altitude*. Tail Gunner, Williams 2 hr. 2 min. 35,000 feet Pain in right arm bad. 6. Engineer, Dumas 2 hr* 35,000 feet • Very uncomfortable, restless. 2 n 3 min* 35,000 n Chest sore; hard to breathe* Mqy be getting chokes* 2 ” 7 w 35,000 11 Started down in air-lock as he was coughing badly. The other three men had no symptoms. Summary: Mission seriously handicapped by Engineer becoming incapacitated from chokes. A pilot was incapacitated, due in part to voluntarily removing mask to see effect of breathing air; the resulting anoxia aggravated the previously mild degree of bends so that he too was incapacitated. MAMU FLIGHT NO. 29 Wednesday, October 7, 19U2, from 1:5>0 to l*;52 p,m, (3°2!) Squadron 372, Crew 2, Flight A D ecompression Mask 1, First Pilot 2nd Lt. S. M. Foster None 2. Pilot 2nd Lt. J. L. Jacobs None A-8-B 3. Pilot 1st Lt. G. F. Mozette None A-8-B U* Navigator 2nd Lt. C. H. Roeman None A-8-B 5# Bombardier 2nd Lt. J. W. Nicholson None A-8-B 6. Radio Operator (Gunner) S/Sgt. E. E. Hoover None A-8-B 7. Radio Operator (Gunner) T/Sgt, W. W, Richardson None A-8-B 8, Eng. Gunner T/Sgt. J. F, Holsey None A-8-B 9* Asst. Eng* Gunner Sgt. R. L. Barratt None A-8-B 10. Armorer (Gunner) S/Sgt. L. A. Schichner None A-8-B Condensed Log of Flight Duration Elevations Highest elevation 35,000 feet Hrs. Min* 26 30,000 - 3U,000 feet 1 58 35,000 feet 'i 2ir over 30,000 feet Results lc First Pilot, Foster 30.000 feet When reaching 30,000 gas pains, so dropped to 25,000 feet. 9 min. 35,000 ,f Pain in left shoulder. 13 ” 35,000 n Pain in left shoulder gone. 3. Pilot, Mozette min, 35,000 feet Severe gas pains. 57 n 35,000 n Less gas pains, U. Navigator, Roeman 1 min, 35,000 u Pain left wrist very severe. Went down air-lock - 35 min, after going up - exercycle 27 min, and went in main chamber again. No further troubles. 7. Radio Operator, Richardson 2 min. 3?,000 feet Gas pains, 30.000 •• Gas pains relieved by temporary decrease in elevation. The other six men had no symptoms. Summary: Navigator incapacitated from bends, thereby interfered seriously with mission; however, after descent in air-lock he denitrogenized and returned to 35,000 feet without further trouble. MAMU FLIGHT NO, 30 Wednesday, October 7, 19U2, from 7ih2 to 9:12 p*m. (l^O1) Squadron 372, Grew 2, Flight A 1. First Pilot 2nd Lt« S* M.Foster 11 min. 3-hi ra/hr. A~o-B 2. Pilot 2nd Lt. J. L. Jacobs 15 min. 3-Ui ra/hr. A-8-B 3. Pilot 1st Lt. G. F, Mozette None B*Deraand Rebr. h. Navigator 2nd Lt. C. H. Rocraan None A-8-B 5. Bombardier 2nd Lt. J* W* Nicholson None Drinker 6. Radio Operator (Gunner) S/Sgt. E. E* Hoover None A-8-B 7 * Radio Operator (Gunner) T/Sgt, W. W* Richardson 23z niin. m/hr. B.Demand 8o Eng* Gunner T/Sgt. J. F, Holsey None A-8-B 9c Asst, Eng. Gunner Sgt* R. L, Barratt 17 min. 3-1*2 ra/hr. Drinker \ .0, Armorer (Gunner) S/Sgt. L. A. Schichner None B.Demand Rebr* Duration Hrs. Min. Elevations Highest elevation iiU,000 feet lU 30,000 - 3U,000 feet 28 35,000 - 39,000 feet 9 U0,000 - Ul,000 feet li U2,000 feet and over I 3 over 30,000 feet Condensed Log of Plight Results 3© Pilot, Mozette 10 min. 35,000 feet Gas pains very bad* 27 ,f 35,000 feet Went in air-lock and came down to 35,000 while main chamber went to 1*2,000, At 30,000 main chamber coming down and level with air-lock - door to chamber open and air-lock and main chamber came down together* The other nine men had no symptoms• Summary; Pilot’s gas pains severe and mission would have been interfered with if it had been necessary to go above 35,000 feet. MA.MU FLIGHT NO. 31 Thursday, October 8, 19U2, from 9:18 a.m. to 12:16 p.m. (2°58j) Squadron 372, Crew 2, Flight a Decompression Mask lo Pilot 2nd Lt. S. Mv Foster None Drinker 2. Pilot 2nd Lt. J. L. Jacobs 11 min, £ miP/hr« Demand Refer, 3, Pilot 1st Lt. G. F, Mozette 20 min0 9 mi,/hr. A-8-B U. Navigator 2nd Lt. C, H. Roeman None B, Demand 9, Bombardier 2nd Lt, J. W, Nicholson None A-8-B 6, Radio Operator S/Sgt. E, E, Hoover None Demand Refer, 7* Radio Operator T/Sgt, W, W. Richardson 8. Eng. Gunner T/Sgt, J. F. Holsey None Drinker 9* Ass, Eng. Gunner Sgt. R, L. Barratt 13 min. exercycle A-8-B 10, Armorer (Gunner) S/Sgt, L, A, Schichner None Duration Elevations Highest elevation U0,000 feet Hrs. Min* 6 30,000 - 3U,000 feet 2 23 35,000 - 39,000 « 6 U0,000 feet 2 "IT" over 30,000 feet Condensed Log of Flight Results Iu Navigator, Roeinan 2 hr. 30 rain. 35,000 feet Pain left knee. 7. Radio Operator, Richardson - Did not go up on this run. 8. Eng. Gunner, Holsey 35,000 feet Dizzy when arrived at 35,000 feet. Emergency oxygen mask turned on followed by improvement. The other seven men had no symptoms. Summary: No interference with mission by bends. MAMU FLIGHT NO. 32 Thursday, October, 8, 191*2, from 1:1*2 p*m. to 1*:53 p*m, (3°11 •) Squadron U2U, Crew 9 1. Pilot 1st Lt0 D. D, Deuchare Decompression None Mask 3ms 2, Pilot 1st Lt. C. A, Friend None A-8-B 3. Pilot 1st Lto R, W, Rowe None A-8-B h. Navigator 1st Lto C. R. Wade None Bb Demand Rebr. S. Bombardier 1st Lt« P. C. Crane None A-8-B 6. Tail Gunner Cplo Fe Magri None A-8-B 7. Gunner 8gt* N. A. Ward None A-8-B 8. Radio Operator S/Sgt. E, J. Beaupre None A-8-B 9o Engineer S/Sgt. F, ki Woods None Drinker .0, Engineer S/Sgt* K. C• McCarthy None A-8-B Condensed Log of Flight Duration Elevations Highest elevation U2,000 feet Hrs# Min# 16 30.000 - 3k,000 feet 1 2 35.000 - 39,000 feet 2 Ii0,000 - Ul.000 feet 1 20 over 30,000 feet Results 1* Pilot, Deucharo 32 min* 35?000 feet Pain both knees; flow up, exercise, no better. U3 M 35,000 " No better. 30.000 n Went down; no better., 1 hr. 12 " 35,000* « Still has bends (35,000). 1 hr, ii6 " 35,000* " Bends better (35,000), 30.000 n Bends gone. 6* Tail Gunner, Magri 2u min. 35,000 feet Cramps stomach while sitting; better standing. 10. Engineer, McCarthy 35.000 feet Pain calf, ankle and foot of left leg; exercised. 1 hr. U min. 35,000+ ” Bends better. 30.000 H Coming down bends gone* The other seven men had no symptoms. Summary: Pilot, Tail Gunner and Engineer had severe but not incapacitating bends. MAMU FLIGHT NO. 33 Friday, October 9, 19ii2, from 8:R9 a.m. to 11: U6 a.m. (2°57!) Squadron h2h» Crew 9 Decompression Mask 1* Pilot 1st Lt. D. D. Deuchare 2. Pilot 1st Lt. C. Ao Friend 3. Pilot 1st Lt* R, V/. Rowe U« Navigator 1st Lt* C. R. Wade None A-8-B 5. Bombardier 1st Lt. P. C. Orane None B. Demand Rebr. 6, Tail Gunner Cpl. J* F. Magri 2h min. 3 mi./hr. A-8-B 7. Gunner Sgt. N. i*. Ward None A-8-B 8, Radio Operator S/Sgti E* J, Beaupre None Drinker 9. Engineer p/Sgt. F, a. Woods 29 min. 3 mi*/hr* A-8-B 10. Engineer B/Sgt. K, C. McCarthy 17 min. exercycle A-8-B Condensed Log of Flight Duration Elevations Highest elevation U3,000 feet Hrs• Min. 15 30,000 - 3U,000 feet 1 32 35,000 - 39,000 " 1 1-0,000 - Ul,000 " 2 U2,000 - Ul.000 " . i Ho over 30,000 feet Results 1» Pilot, Deuchare - Refused to go up - claustrophobia. 2. Pilot, Friend - Did not go up - had a cold. 3. Pilot, Rowe - Did not go up - had a cold Summary: None of the men had symptoms. Mission successful. mm FLIGHT NO. 3k Friday, October 9, 19l*2, from 1;2£ io Us28 pAm. (3°6!) Squadron 370t Crew 7, Flight C Decompression Mask 1. Pilot 1st Lt, U, J, Newman None 2* Co-Pilot 2nd Lt. R. J. Kissel None A-8-B 3. Navigator 2nd Lt. J, A, Newton None U. Bombardier 2nd Lt. W, L, Shirey None Drinker Tail Gunner Sgt. A. T, Kiester None 6. Radio Operator S/Sgt. H, R. Wolf None A-0-B 7* Asst, Radio Opr, S/Sgt. F, J. Deflo None A-8-B 8, Engineer Sgt. J. L. Knisley None A-8-B 9* Asst, Engineer S/Sgt, G, W, Gathers None Drinker 10.. Asst. Oper, Off, 2nd Lt. Kidder 30 min, 3 m/hr. A-8-B il. Flight Surgeon Capt, M, C . Spoeneman None B, Demand Rebr. Duration Elevations Highest elevation 1*0,000 feet Hrs. Min. 1 20 30,000 - 31,000 feet 1 10 35,000 - 39,000 feet 9 1*0,000 feet 2 39 over 30,000 feet Condensed Log of Flight Results 2* Co-Pilot, Kissel 23 min* 35-1*0,000 feet Pain right shoulder; chest pain* 2? ” 35-1*0,000 n Pain right shoulder severe (1*0,000) 28 11 35-1*0,000 b Came down in air-lock* Exercised 30 min* on exercycle. Went up in air-lock to main chamber again* 3 11 35,000 M Pain left shoulder. 7 11 35,000 M Pain better 8 ft 3£,000 n Pain left elbow* 3* Navigator, Newton 1*5 mih* 35-1*0,000 feet Pain left knee; exercised (35,000). 1 hr* 30-1*0,000 ” Pain left knee no better (30,000). 1 hr. 20 11 30-1*0,000 « Pain left knee very bad, exercising (35,000). 1 hr. 21 " 30,000 " Some relief* I*. Bombardier, Shirey £*5 min* 35-1*0,000 feet Pain left forearm (35,000) 56 n 30-1*0,000 tt Pain left forearm better (30,000). 1 hr. 19 " 30-1*0,000 " Bends left am (35,000). The other eight men had no symptoms. Summary; Co-Pilot incapacitated from bends and this would have interfered with mission. Navigator and Bombardier also severe but not incapacitating bends. MAMU FLIGHT NO. 35 Friday, October 9, 191*2, from l*:i*6 p.m. to 6:3U p*m. (l°U8f) Squadron 371, Crew 2, Flight A Decompression Mask 1* Pilot Lt* J* R. Irby None Demand Rebr, 2. Co-Pilot Lt * L, M. Esmond None B* Straight Demaid 3* Navigator Lt* M, E, Smith None A-8-B U* Bombardier Lt. R* I. Priester None a-8-B 5>* Rear Gunner Sgt* T* Ai Hopper None A-9-B 6* Radio Operator Sgt* Ri W, Drew None Drinker 7. Asst* Radio Opr* Sgt. H. R* Leffew None A-e-B 8* Engineer Sgt. D. J. Howell None A-8-B 9* Asst* Engineer Sgt* L* F. Duster None ii-8-B 10* Asst* Operations Off* Lt, R* W. Holland None B* Demand Rebr* Duration Condensed Log of Flight Htsj Uin* Elevations Highest elevation UOjOOO feet 9. 30,000 - 3U,000 feet 1 9- s 35,000 - 39,000 » 3 U0,000 feet 1 21 over 30,000 feet Results 2. Co-Pilot, Egmond 35.000 feet Did not look good* 53 min* 35,000 n Coughing; may be chokes but says he is all right* 1 hr# 1 " 35-UO,000 feet When reached dropped immediately to let subject out in air-lock* At lii,000 pain cleared up. U* Bombardier, Priester 1 hr. 35,000+ feet Pain below knee (U0,000), 30.000 ” Came down, better* 1 hr, 8 min* 35“U0,000 feet Knee worse, , 25,000 feet Pain gone, 6* Radio Operator, Drew , 1 hr* 8 rain* 35-U0,000 feet Pain at knee; went down immediately (U0,000). 1 hr* 10 n 35-U0,000 M Pain better. 25.000 *• Pain gone. . 8* Engineer, Howell 35.000 " Unconscious - oxygen must have been turned off accidentally. Dropped emergency mask on; all right* Did not know he passed out. 9. Asst, Engineer, Duster . 1 hr. 7 min* feet Pain in right ankle (U0,000). 1 M 10 » : 35-1*0,000 u Better 25.000 11 Pain gone The other five men had no symptoms. Summary: Co-Pilot incapacitated by chokes and thus seriously jeopardized mission. MAMU FLIGHT NO. 36 Saturday, October 10'7T9lI5^^rom^7TlI5-to 10:27 a.m. (2 JUl1) Squadron 370, Crew 7, Flight C 1. Pilot 1st Lt. U. J. Newman Decompress ion None Mask B. Demand Rebr. 2. Co-Pilot 2nd Lt. R. J. Kisael 30 min. exercycle A-8-B 3. Navigator 2nd Lt. J. A# Newton 21 min. 3 m./hr. A-8-B h. Bombardier 2nd Lt. W. L, Shirey — Tail Gunner Sgt. A. T. Klester None Drinker 6. Radio Operator S/ggt. H. R, Wolf None B. Demand Rebr. 7. Asst. Radio Opr. S/Sgt. F, J, Deflo None B. Demand Rebr. 8, Engineer Sgt. J. L. Knisley None A-8-B 9* Asst. Engineer S/Sgt. G, W. Gathers None A-0-B 10, Flight Surgeon Capt. M, C, Spoeneman 21 min. 3 m./hr. A-8-B Condensed Lo g of Flight Duration Elevations Highest elevation U0,000 feet Hrs* Min* 2 30,000 - 3l*,000 feet 2 6 - 39,000 »» 2 UP,000 feet 2 10 over 30,000 feet Results 1* Pilot Newman 10,000 feet On way down twitching leg above knee. Put mask on, no change. Oxygen did not help, 2. Co-Pilot, Kissel 1 hr, 16 min. 35-1*0,000 feet Chest pressure (1*0,000), 1 11 21 n 35-1*0,000 11 Still chest pressure (35,000). 1 11 50 M 35,000 feet Slight chest pressure (35,000). 8, Engineer, Knialcy 1 hr* 9 min, 35,000 feet Slight pain right knee, exercised, 1 u 16 11 35-1*0,000 feet Pain worse (1*0,000). 1 « 20 " 35-1*0,000 » Pain better (35,000), 1 ” 28 " 35-1*0,000 « Knee all right (35,000), 1 ,! 3U 11 35-1*0,000 11 No pain in knee (35,000), lu Bodbardicr, Did not make flight because of ears. The ether six men had no gyuptpi.g» Summary: Mission cerrect and satisfactory. MAMU FLIGHT NO, 37 Saturday* October 10, 19U2, from 10:37 a.ra. to 1:11 p.m. (2°3Uf) Squadron 371, Crew 2, Flight A Decompression Mask 1. Pilot Lt. J, R, Irby None A^BTb 2, Co-Pilot Lt, L. M. Esmond 3* Navigator Lt* M. E, Smith None Demand Rebr. U. Bombardier Lt. R. I. Priester 29 min. 3 mi./hr. A-Q-B Rear Gunner Sgt, T. A. Hopper None Drinker 6> Radio Operator Sgt. R. W, Drew 29 rain, 3 mi*/hr* A-8-B 7. Asst. Radio Opr. Sgt. H, R. Leffew None B, Demand 80 Engineer Sgt. D, J, Howell None Drinker 9o Asst. Engineer Sgt, L. F. Duster .0. Asst. Opr, Off, Lt. R, W. Holland None A-8-B Condensed Log of Flight Duration Elevations Highest elevation U3,000 feet Hrs. Min, h 30,000 - 3U,000 feet 1 56 35,000 - 39,000 " 1 U0,000 - Ul,000 " 1 U23000 and over 2 2 oyer 30,000 feet Results 6. Radio Operator, Drew 1 hr. 31 min, 35,000 feet Pain left knee 1 hr. 35 n 35,000 11 Pain left knee better 1 11 ill " 35,000 H Pain left knee again. 1 11 U8 11 35,000 11 Still pain left knee, no worse. 1 ” 5U " 35-U3,000 feet Gr. 3 pain knee at i;3,000 feet. 30.000 feet Goming down, knee better. 9. Asst. Engineer, Duster - Did not go up. Cold and bad ear, 10. Asst. Opr. Officer, Holland 1 hr. 57 min. 35-140,000 feet Pain shoulder (U3,000). 30.000 '» Better.* The other six men had no symptoms. Summary: Mission carried out successfully. MAMU FLIGHT NO, 36 Saturday, October 10, 191*2, from 1*;00 to 5s 13 p.m, (l°13’) Squadron 372, Crew 3, Flight A Decompression Mask 1. Pilot 2nd Lt. J • H. Storer None B. Demand Refer. 2. Co-Pilot 2nd Lt. F . G. Craven None B. Demand Refer. 3. S/Sgt. B# Gianoli None Drinker h. Bombardier 2nd Lt. N . A. Nelson None A-8-B Tail Gunner S/Sgt. R. 0. Scherer None A-8-B 6. Top Turret Gunner S/Sgt. c. I. Knutson None A-8-B 7* Radio Gunner E. J. Bloom None B. Demand Refer. 8U Radio Operator S/Sgt. D. S, Orlando None Condensed Log of Flight Duration Elevations Highest elevation U0,000 feet Hrs • lKn9 17 30,000 - 3U,000 feet 20 35,000 - 39,000 feet ■ 1 U0,000 feet “3B over 30,060 feet 2, Co-Pilot, Craven 29 min* 25-35,000 feet Feels funny; cannot describe, 30 11 35,000 feet Color bad. Emergency oxygen on, 32 w 35,000 ,f Color bad even with emergency oxygen. Has a painful tooth, 39 ” 35-1*0,000 feet Pain left leg, hip; painful tooth (1*0,000). 1*1 " 30-1*0,000 " Color bad (30,000). 27,000 feet Color better* Feels better, 3. Gianoli 9 min, 35,000 feet Pain left knee, exercised, 11 " 35,000 « Pain worse ll* M 35,000 11 Pain bad; dizzy; color bad; sleepy, 15 11 35,000 ,r Passed out a second. Put in air-lock and down 21* min. after starting up* 1*, Bombardier, Nelson 39 min, 35-1*0,000 feet Pain right foot (1*0,000). 8* Radio Operator, Orlando 21* min, 35,000 feet Itching right leg* 38 11 35-1*0,000 feet Pain left shoulder (1*0,000). Results The other four men had no symptoms. Summary: S/Sgt. Gianoli incapacitated from bends in 15 minutes; although a short mission, it would have been handicapped. MAMU FLIGHT NO. 39 Saturday, October 10, 19U2, from 3:22 p.m. to 6:39 p.m. (1°1T») Squadron h2h» Crew 8, Flight C Decompression irtask 1. Co-Pilot 2nd Lt, H, R, Vanderslice None 2c Navigator 2nd Lt, W, M, Carroll None B, Demand Rebr, 3, Bombardier 2nd Lt. D, A, DeClerique None Drinker lu Tail Gunner Sgt, J, W, Sargent S, Radio Operator Sgt, R, 0, Smith None A-8-B 6v Radio Gunner Sgt, L* C, Averitt None A-8-B 7o Engineer Gunner S/Sgt. W. H. Adams None A-8-B 8-, Engineer Gunner S/Sgt, R, N, Lund Duration Elevations Highest Elevation U3,000 feet Hrs. Min* 2 30,000 - 3U,000 feet 5h 35,000 - 39,000 *» 1 U0,000 - la,000 « 1 U2,000 - and over 5« over 30,000 feet Condensed Log of Flight 1. C»-Pilot, Vanderslice 55> min* 33-U3>000 feeV Slight pain knee (U0,000). 3. Bombardier, DeClerique 35 min. 35-U3,000 feet Pain knee (U3,000). 36,000 feet Pain gone. Iu Tail Gunner, Sargent - Did not go up because of cold. 8. Engineer Gunner, Lund - Did not go up because of cold. The other four men had no symptoms. Results Summary: No interference with mission* MAMU FLIGHT NO* UP Sunday, October 11, 19U2, from 7:ii3 to 10:32 a.mu (2°U9f) Squadron 372, Crew 3, Flight A 1. Pilot 2nd Lt, J. H. Storer Decompression None Mask 2. Co-Pilot 2nd Lt, F, G, Craven 30 min* 3 m/hr0 A-8-B 3. S/Sgt, Bo Gianoli 30 min, 3 m/hr* A-8-B U. Bombardier 2nd Lt. N. A* Nelson 30 min, 3 m/hr. Bo Demand Rebr* Tail Gunner S/Sgt, R. 0, Scherer None P, Demand Rebr« 6. Top Turret Gunner S/Sgt, C. L Knutson 7. Radio Gunner E* Jo Bloom None A-8-B 8. Radio Operator S/Sgt* D. So Orlando 30 min, exercycle A-8-B Duration Elevations Highest elevation 35,000 feet Hrs. Min* 29i 30,000 - 3h,000 feet 2 2 35,000 feet 2 32 over 30,000 feet Condensed Log of Flight Results 1. Pilot, Storer 1 hr, hi min* 30-35,000 feet Pain knee, exercised, somewhat better (30,000). 1" 56 11 30-35,000 " Pain worse (35,000). 2 " 12 " 30-35,000 « Pain gone (30,000). 3# Gianoli 1 hr. 26 min. 35,000 feet Pain chest. Wants to cough (35,000). 30-35,000 feet Came down; feels better (30,000). 1 hr. 56 !1 30-35>000 11 Pain right and left knee (35,000). 2 « 2 " 30-35,000 " Pain about the sane (35,000). 2 » 12 " 30-35,000 " Pain gone (30,000). iu Bombardier, Nelson U5 min* 35,000 feet Did not feel so good. Turned flow up. 1 hr* 15 M 35,000 ” Feels and looks sleepy. 6, Top Turret Gunner, Knutson Did not go up because of cold and bad ear. The other four men had no symptoms. Summary; No interference with mission* MAMU FLIGHT NO, Ul Sunday, October 11, 19U2, from a.m. to 1:19 p.m. (2°3U1) Squadron U2U» Crew 8, Flight C Decompression Mask ly Co-Pilot 2nd Lt. H. R. Vanderslice None 2~ Navigator 2nd Lt. J. M. Carroll None B, Demand Rebr. 3 • Bombardier 2nd Lt. D. A. DeClerique None A-8-B if, Tail Gunner Sgt. J, W« Sargent S, Radio Operator Sgt,. R. 0. Smith None Demand, A-8-B 6, Radio Gunner Sgt- L* 0. averitt None A-8-B 7o Engineer Gunner S/Sgt> W. Ho Adams None Drinker 3 c» Engineer Gunner S/Sgt. R. N0 Lund Condensed Log of Flight Duration Hr s«. Min* Elevations Highest Elevation 35>000 feet 22 30,000 - 3U,000 feet 1 19 35?, 000 feet 1 hi over 30,000 feet Results 1. Co-Pilot Vanderslice 39 min, 35.-COO feet $>ain knee bad, 51 ,f 35,000 n Pain knee bad; started down. 30.000 M Pain better# 1 hr. 35 M 30,000+ n Pain right knee getting bad (35,000). 1 ” 38 " 30,000+ n Started down, better. 2. Navigator, Carroll 1 hr. 1? min© 30,000+ feet Pain right ankle (35,000). U. bid not go up because of a cold. 5. Radio Operator, Smith 31.000 feet On way up unconscious. Emergency mask on. Looked bad. Came down in air-lock. Put on A-8-B and went up again. No further trouble0 6. Radio Gunner, Averitt 29 min, 35,000 feet Pain right knee, exercised. 30 n 35,000 11 Pain right knee, very bad. 32 11 35,000 M Came down in air~lock. 7. Engineer Gunner, Adams 2 min. 35,000 11 Felt funny. Turned on emergency oxygen, better 1 hr. 30 ” 35,000 " Pain in left knee* 8. Did not go up because of a cold. The other man had no symptoms. Summary; Demand mask or regulator did not function properly and this interfered with mission but not from bends. MAMU FLIGHT NO. U2 Sunday, October 11, 19h2, from 1:1*0 p,m. to U:19 p.m. (2°39!) Squadron 371, Crew 3, Flight A 1 Jecompression Mask 1. Pilot 2nd Lt. J, H, McCloskey None 2, Navigator 2nd Lt. H. A. Thorn None B, Demand 3. Bombardier 2nd Lt, H. S, Smithson None B, Demand U. Station Gunner D, Pc Apple None A-8-B Gunner Sgt e T. J, Dewberry None A-8-B 6, Gunner Ne C, Scott If one B<* Demand ?, Radio Gunner Sgt, S, I. Walker None A-8-B 6. Radio Gunner Sgt, L, E, Anderson None A-8-B Engineer Gunner Sgt, Dean J, Howell None A-8-B 10a Flight Surgeon Capt, N • R, Groth None B. Demand ilc Asst, Open, Off. 2nd Lt, K. M, Kidder None A-8-B Duration Highest elevation U0,000 feet Hrs. Min# Elevations 3 30,000 - 3U,000 feet 2 5 - 39,000 " 2 U0,000 feet 2 11 over 30,000 feet Condensed Log of Flight Results 2. Navigator, Thorn 13 rain. 35,000 feet Light headed. On constant flow. Ih “ 35,000 11 Pain right shoulder. 17 11 35,000 « Better. lu Station Gunner, Apple 10 rain. 35,000 feet Pain right shoulder. 29 ” 35,000 feet Pain right shoulder gone; itching skin, 6, Gunner, Scott 57 min. 35,000 feet Pain right elbow. 1 hr. 6 ,f 35,000 feet Somewhat better. The other eight men had no symptoms. Summary: No interference with mission. HAMU FLIGHT NO. 1+3 Sunday, October 11, 19U2, from U:5>1 to 7sli8 p4ra. (2°57’) Squadron 370> Crew 8, Flight C. 1. Pilot S, T, Gregory Decompression None Mask B, Demand 2, Pilot H, C. John None Drinker 3* Navigator 2nd Lt* D. E, Parker None A-8-B lu Bombardier 2nd Lta H. A, Sterhel None B, Demand 5 Currier Sgt.-. Ac T. Chuchzek None A-8-B 6, Itadio Gunner G/Sgt. W, E, Morgan None A-8-B 7Ft, Gunner S/Sgt, G, F, Parker None A-8-B 8- Engineer Sgt, W(, G. Hardin None B; Demand Duration Elevations Highest elevation U0,000 feet. HrSc Min. 20 30,000 - feet 1 11 35,000 - 39,000 »• 2 UOjOOO feet 1 33 over 30,000 feet Condensed Log of Flight Results 5. Gunner, Chuchzek 13 min. 35,000 feet Gas pains - stood up. 15 11 35,000 ” Gas pains better. 26 w 35,000 11 Gas pains worse - went down to 30,000 relieved. U5 11 30,000 - 35,000 Brought down in air lock - toilet - went back up - no more gas pains. The other seven men had no symptoms. Summary: No interference with mission. MAMU FLIGHT NO. 1*1* Monday, October 12, 19l*2, from 7-U6 a.m. to 10:2l* a.m. (2°38f) Squadron 371, Crew 3» Flight A Decompression Mask 1. Pilot 2nd Lt, J. R. McCloskey None B. Demand 2. Navigator 2nd Lt. H. A. Thorn 19 min. exercycle A-8-B 3, Bombardier 2nd Lt. H. S, Smithson None A-8-B U* Station Gunner D. P. Apple 32 min. 3 mi./hr. Drinker Gunner Sgt. T. J. Dewberry None A-8-B 6 c Gunner N. c. Scott 19 min. 3 mi./hr» A-8-B 7. Radio Gunner Sgt. S. I. Walker 8* Radio Gunner Sgt. L. E. Anderson None Bo Demand 9. Engineer Gunner Sgt. D. J. Howell None B. Demand 10, Flight Surgeon Capt. N . R . Groth None A-8-B Condensed Log of Flight Duration Elevations Highest elevation 1*2,000 feet. Hrs a Min* 6 30,000 - 31,000 feet 1 39 3S,000 - 39,000 « 6 !i0,000 - Ul,000 " 1 Si over 30,000 feet Results 5. Gunner, Dewberry 1*2,000 feet Color bad* Light headed. 1*0,000 11 Feels better. 7* Radio Gunner, Walker - did not go up. 9. Engineer Gunner, Howell 1*5 min. 35,000 feet Pain left knee; exercised, turned up constant flow. 51 min. 35*000 ” Pain left knee bad 51* M 35*000 11 Pain a little better. 1 hr. 10 11 35*000 fl Went in air-lock to ground. Incapacitated. The other seven men had no symptoms. Suimnary: Engineer Gunner incapacitated and thus interfered with mission* MAMU FLIGHT NO, U5 Monday, October 12,from 10:35 to 1:35 p.m. (3°) Squadron 370, Crew 8, Flight C Decompression Mask 1. Pilot S, T. Gregory 23 min., 3 m/hr* I=B=B 2* Pilot H. C. John None Drinker 3* Navigator 2nd Lt• D. E, Parker None U* Bombardier 2nd Lt* H. A* Sterhel Gunner Sgt. A, T. Chuchzek 22 min* 3 m*/hr* A-8-B 60 Radio Gunner S/Sgt* W. E* Morgan None s-8-b 7o R. Gunner S/Sgt* G* F* Parker None 8* Engineer Sgt* W* G. Hardin None A-8-B Condensed Log of Flight Duration Elevations Highest elevation U0,000 feet* Hrs* Min. * U6 30,000 - 3U,000 feet 1 19 30,000 - 39,000 « 3 1;0,000 feet 2 8 over 30,000 feet Results ii, Bombardier, Sterhel Did not go up - had a cold, 8, Engineer, Hardin I4.8 min* 35,000 feet Pain right wrist, gr, 1* $3 " 35,000 ” Pain right arm, gr, 1, The other six men had no symptoms. Summary: No interference with mission* MAMU FLIGHT NO. U6 Monday, October 12, 19l*2, from 1:1*6 pem* to 1*:10 p.m. (2°32’) Squadron I*2i*, Crew 2. Flight A 1. Pilot 2nd Lt. V/, R, Hitchcock Decompression None Mask Bo Demand Rebr. 2. Co-Pilot 2nd Lt. Ho J, Ladd None B« Demand 3. Navigator 2nd Lt a E0 J. Bauman None Drinker lie Bombardier 2nd Lt. W. D. Hughes None Demand Gunner Cpl. J. W. Wycoff None B. Demand Rebr» 6* Radio Operator Cple Bo E. Byrd None A-8-B Asst, Radio Opr. S/Sgt. L. J. Chialostii None A-8-3 8a Engineer S/Sgta D. K, Long None A-8-B 9« Asst. Engineer Sgtc J. J. Kiback None A-8-B .0. Operations Off. Lt, R0 S. Boydston 30 rain, exercycle A-8-B Condensed Log of Flight Duration Elevations Highest elevation U3,000 feet Hrs o Min. 17 30,000 - 31,000 feet 1 18 35,000 - 39,000 « 7 U0,000 - hi,ooo « 1 U2.000 feet and over "I w over 30,000 feet Results In Pilot, Hitchcock 1 hr# 22 min# 35,000 - 1*3,000 feet Slightly dizzy at 1*3*000 feet© 1 hr# 22 min© 35,000 - 1*3,000 feet Coming down dizziness gone (1*0,000)# L*# Bombardier, Hughes# 1 hr# 15 min# 35,000 - 1*0,000 feet Cramp pain right leg© 1 n 29 ” 35,000 - 1*3,000 “ Cramp gone. The other eight men had no symptoms# Summary: No interference with mission© MAMU FLIGHT NO. U7 Monday, October 12, from Us36 to 6:5l p.m* (2°l5’) Squadron 372, Crew U, Flight B Decompression Mask 1. Pilot Capte D. B. Billings None Demand 2. Pilot 1st Lt. E« E. Elliott None Drinker 3» Navigator Lt. L. T* Monogue None Drinker U* Bombardier Lt. R. F, Wadlin None Demand Radio Operator & Gunner S/Sgt. V. E. Anderson None A-8-B 6, Engineer Gunner S/Sgto Ec Hatt None A-8-B ?• Engineer Gunner S/Sgto V, p„ Hopkins None ji-8-B 8c Tail Gunner (Station) Pvt. R. R. Mosier None A-8-B 9* 2nd Oper. Gunner S/Sgt. B. E. Conner None A-8-B Condensed Log of Flight Duration Elevations Highest elevation U3,000 feet Hrs« Min„ 38 30,000 - 3U,000 feet 1 1*9 35,000 - 39,000 » 3 U0,000 - la,000 " 2 U2,000 and up 2 32 over 30,000 feet Results 2S Pilot, Elliott 1 hr. 1 min0 30-11-3,000 feet At U2,000 pain in knee, 1 n 3 ” 30-U3,000 feet At 33,000 pain gone, 3« Navigator, Monogue 11 min© 3!?,000 feet Pain in left knee -exercised, 20 11 35,000 11 Turned up emergency ©2* 35 ” 35,000 n Pain both knees, U, Bombardier, Wadlin 21 min0 35,000 feet Sweating, 31 n 35,000 11 Emergency 0g on and in air-lock. The other six men had no symptoms. Summary: Bombardier incapacitated but not from bends; cause unknown* MAMU FLIGHT NO, U8 Tuesday, October 13* 19U2, from 7:ii3 a,m, to 10:28 a.ra, (2dU5f) Squadron U2U« Crew 2, Flight A 1. Pilot 2nd Lt„ W, R, Hitchcock Decompression None Mask 2, Co-Pilot 2nd Lt, H0 J, Ladd Nona A-8-B 3. Navigator 2nd Lt, E. J, Bauman None A-8-B h. Bombardier 2nd Lt, W, D. Hughes None A-8-B 5. Gunner Cple J, W. Wycoff None Demand Rebr® 6, Radio Operator Cpl, B, E, Byrd None A-8-B 7 > Asst, Radio Opr, S/Sgto L, J. Chialostii None Drinker 8. Engineer S/Sgt* D« K, Long None Demand 9u Asst, Engineer Sgt, J, J, Kiback None Demand Duration Elevations Highest elevation 35>000 feet Hrs* Min# 11 30,000 - 3U,000 feet 1 53 35»000 feet 2 k over 30,000 feet Condensed Log of Flight Results 4-- Bombardier, Hughes U9 min, 35,000 feet Slight pain knee and hip. 5U 11 35,000 m Pain worse. 55 ” 35,000 n Pain very severe knee and chest. Chokes; dizzy. Went out a few seconds. Did not know it. Went down in air-lock. Weak after coming down;, ?e Asst. Radio Opr*, Chialostii 36 min. 35,000 feet Emergency oxygen on. 1 hr, 30 11 35,000 fl Emergency oxygen off, 1 11 h6 ,f 35,000 ,f Did not feel good; coughing. 2 ” 1 11 35,000 n Went down in air-lock. 9m Asst. Engineer, Kiback 1 hr. 19 min, 35,000 feet Emergency oxygen on. The other six men had no symptoms. Summary: Both Bombardier and Assistant Radio Operator completely incapacitated. This would seriously interfere with mission. MAMU FLIGHT NO, 1*9 Tuesday, October 13, from 10:39 a.m. to 1;08 p.m* (2°29!) Squadron 372, Crew U, Flight B Decompression Mask 1. Pilot Capt* D. B. Billings 18 min* 3 m./hr. 5THIB 2. Pilot 1st Lt. E. E. Elliott 29 min. 3 m./hr. A-8-B 3* Navigator Lt. L. T, Monogue 26 min. 3 m./hr. A-8-B U. Bombardier Lt. R, F. Wadiin None A-8-B 5* Radio Operator & Gunner S/Sgt. V. E. Anderson None Drinker 6a Engineer Gunner S/Sgt« E« Hatt None A-8-B 7* Engineer Gunner S/Sgt«, V. P. Hopkins None Drinker 8. Tail Gunner (Station) Pvt. R. R. Mosier None a-6-B 9* 2nd Oper. Gunner S/Sgt, B. E. Conner None B Rebr. Condensed Log of Flight Duration Elevations Highest elevation feet Hrs. Min* 8 30,000 - 3U,000 feet 1 9 35,000 - 39,000 feet 9 140,000 - la,000 feet JL. a U2,000 feet and up 1 27 over 30,000 feet Results 2a Pilot, Elliott No symptoms, but came late - -went up in air-lock (23 rain* late). 7* Engineer Gunner, Hopkins 1 hr. 12 min, 35-01,000 feet Pain left wrist (U2.000), 1 ” 1U « 35-UU,000 « Pain better (35,000). 1 11 19 ,f 35-UU,000 ” Pain right knee - exercising (35,000). 1 " 25 11 35-04,000 11 Pain right knee better - feels stiff (35,000). 25.000 feet Knee all right, 9* 2nd Oper, Gunner, Conner 20.000 feet Discharge from ear. 20 min, 35,000 H Ear feels better, 1 hr, 3 11 feet Drainage from ear stopped Examination after run - by Cunningham - ruptured ear drum - possibly raptured on way up. The other seven men had no symptoms. Summary: No interference with mission. MAMU FLIGHT NO. 50 Tuesday, October 13, from 1:1*6' p.m* to 3:23 p.m. (1°351) Squadron 371, Crew 5, Flight B Decompression Masks 1* Pilot 2nd Lto G. E. Hoefler None So Demand 2. Co-Pilot 2nd Lt, N, G, Guiberson None Bo Demand Hebr. 3* Navigator 2nd Lt* a. B. Sheaffer None a-8-B iu Bombardier 2nd Lt* 0, A. Severson Engineer S/Sgt, P, J. Hilgart None A-8-B 6, S/Sgt, 0* K. Iverson None Bo Demand 7. S/Sgt• ¥, E. Sellers None A-8-B 8* S/Sgt. P. Spitaels None A-8-B 9. B, Bailey None A-6-B Condensed Log of Flight Duration Elevations Highest elevation 35>000 feet Hr. Min. 13 30,000 - 3U,000 feet 37 35,000 feet ~w over 30,000 feet *-2o Co~Pilot, Guiberson lU mine 35,000 feet Slight pain left elbow* 17 ” 35,000 n Pain severe* 30.000 ” Came down, much better* 2U M 30,000+ 11 Bad pain left arm* UU ” 30,000+ M Came down in air-lock. U* Bombardier, Severson - Did not make this flight* ?» Sellers 3 rain* 35,000 feet Pain right shoulder and arm* 33 “ 35,000 « Pain left knee. 8* Spitaels 7 rain. 35,000 feet Pain shoulder, arm also numb; slight cyanosis* 9 u 35,000 *’ Came down in air-lock, 9a Bailey 3 min, 35,000 feet Pain left shoulder and arm* 30.000 •’ Coming down - sinus headache. Better, Quite severe higher up* The other four men had no symptoms* Results Summary; No interference with mission. * Bends both shoulders; transient left temporal hemianopsia* Erythema about the area of pain due to bends insertion of deltoids. Hemianopsia last one-half hour. Disappeared suddenly* Weakness in convergence. Diplopia when attempted to look at objects nearer than 5 inches. Diplopia lasted longer than hemianopsia* Erythema associated with increased warmth of skin. LA1.JJ FLIGHT NO. 5l Wednesday, October lU, 19U2, from U:32 p.m0 to 6z2k p.m. (l°52') Squadron 370, Crew Flight B Decompression Mask 1« Pilot 1st Lt. D. E. Macdonald None Drinker 2. Co-Pilot 1st Lt. S, B. Bledsoe None Drinker 3. Navigator 1st Lt« J. R, Wood None Demand Rebr. L. Bombardier 1st Lt. H. A. Nasburg None A-8-B 5 * Engineer Gunner S/Sgt« V, Kiviat None A-8-B 60 Asst. Eng. Gunner S/Sgt, R. Flohr None Drinker 7. J. R. Scritchfield None 8. Sgt. J. G, Jaffe None Demand Rebr. 9* Sgt. Ea G. Heggenbothan, Jr. None Demand 10. Flight Surgeon Major Murray None Demand Duration Elevations Highest elevation U3,000 feet. Hrs. Min. 36 30,000 - 3U,000 feet 27 3$,000 - 39,000 »« h UQ,000 - ljl}000 " 1 Ij2,000+ " l 6 over 30,000 feet Condensed Log of Flight Results 1* Pilot, Macdonald 23 min* 30*000 feet Slight pain in wrist. 33 11 30,000 - 35,000 Pain wrist worse (35*000). 38,000 feet 36 30,000 - 38,000 Emergency mask on and down in air-lock (38,000). 3o Navigator, Wood 37 min* 30,000 - 143*000 Slight pain wrist, old fracture (35*000). SU » 30,000 - U3,000 Leg feels asleep (35*000). The other eight men had no symptoms* Summary: Pilot had incapacitating bends thus interfering seriously with mission. MAMU FLIGHT N0„ 52 Wednesday, October lU, from 7:U3 a.m. to 10:29 a.m. (2°U6!) Squadron 371, Crew Flight 5 Decompression Mask lo Pilot 2nd Lt. Go E, Hoefler None ct-b 2. Co-Pilot 2nd Lt.. No G, Guiberson 27 min0 3 mi,/hr. A-3-B 3«. Navigator 2nd Lt, A, Sheaffer None Demand Rebr, iu Bombardier 2nd Lt, 0, Severson Engineer S/Sgt. P, J, Hilgart None A-8-B 6, S/Sgt, 0, K. Iverson None A-8-B 7. S/Sgt, We E, Sellers 20 min, exercycle A-3-B 8. S/Sgt, Po Spitaels 27 min, 3 mi,/hr. Drinker 9. Be Bailey Duration Elevations Highest elevation U0,000 feet* Hrs. Min» 3U 30,000-3U,000 feet 1 20 35,000-39,000 feet 1 U0,000 feet 1 56 over 30,000 feet Condensed Log of Flight 3» Navigator Sheaffer b min. 35,000 feet Felt dizzy* Constant flow on; better. 30 11 35,000 11 Pain right wrist. 39 ,! 35,000 n Pain worse; better, going away. Some rash. U6 11 30-35,000 feet Much better 50 « 30-35,000 " Pain wrist gone (30,000). 1 hr. 10 11 30-35,000 11 Went up, pain in wrist again (35,000). 1 ” 13 " 30-35,000 « Pain in wrist better (35,000). 1 23 ” 30-35,000 " Pain ankle (35,000); pain better when standing* 1" U2 « 30-35,000 ” Color bad (35,000). 1 ,f 1*5 n 30-35,000 ” Pain right knee. Looks bad (35,000). 30.000 ” Pain gone. U. Bombardier, Severson - Did not make this flight. 7. Sellers 1 hr. 31 rnin. 30-U0,000 feet Pain right knee at 1±0,000. 1 11 33 ,f 30-U0,000 11 Pain right elbow at U0,000, 1 n 39 11 30-U0,000 11 Pain elbow gone but still in knees (35,000). 1 " U8 *» 30,000 « Pains gone. 8. Spitaels 23.000 feet Color bad; emergency oxygen on. 25.000 n Color better. 35.000 11 Changed to A-8-B, No further trouble. 9o Bailey - Did not make this flight. The other four men had no symptoms. Results Summary: Navigator had severe bends but not incapacitated. MAMU FLIGHT NO, 53 Wednesday, October ll*, 191*2, from 10:55 a.m, to 1:1*5 p.ra. (2°50') Squadron 370, Crew Flight B Decompression Mask 1. Pilot 1st Lt* D. E* Macdonald 30 min* 3 mi./hr0A-t3-B 2. Co-Pilot 1st Lt. S* B* Bledsoe None A-8-B 3. Navigator 1st Lt* J* R* Wood 30 minf 3 rai*/hr.A-8-B lu Bombardier 1st Lt* K. A. Nasburg None A-3-B Engineer Gunner S/Sgtc V* Kiviat None B,Demand Rebr* .6, Asst* Eng* Gunner S/Sgt3 R, Flohr 30 rain* 3 mi./hr.A-8-B 7. S/Sgt* J* R* Scritchfield None Drinker 8. Sgt* J. G* Jaffe None B o Demand 9. Sgt* E* G* Heggeribathan, Jr* None B 9 Demand Condensed Log of Flight Duration Elevations Highest elevation 1*0,000 feet Hr* Min* 16 30,000 - 3h,000 feet 2 5 35,000 - 39,000 « 1 1+0,000 feet 2 22 over 30,000 feet Results 1© Pilot, Macdonald U2 min. 35,000 feet Pain left shoulder seems to be worse on inspiration© £7 « 35,000 " No pain. 8. Jaffe 1 hr. 2U min. 35,000 11 Blew nose. 1 11 37 ” 35-UOjOOO feet At 1*0,000 felt faint, coughing, 1 0 39 11 30,000 feet Feels better but severe chest pain. 1 « 1*2 " 30,000 " Still feels bad (30,000). 1 M U9 11 30,000 n Went down in air-lock, 9. Heggenbothan 146 min. 35,000 feet Emergency oxygen on a little. No symptoms. The other six men had no symptoms. Summary: Sergeant had severe bends and was incapacitated and mission jeopardized# Wednesday, October lli, 19U2, from It: 17 p.m, to £:U0 p.m, (l°23!) MAMU FLIGHT NO, Squadron 372, Crew Flight B 1. Pilot Lts Jo R, Boyd Decompression None Mask Demand 2. Pilot 1st Lt, P. L, Veith None A-8-B 3. Co-Pilot 1st Lt* I. M, Osborne None Demand ii. Navigator 2nd Lt, L, A, Kozov None A-8-B 5, Bombardier 2nd Lt. M. L. Cypress None A-8-B 6., Tail Gunner S/Sgt. G. Smith None A-8-B 7® Radio Operator T/Sgt, He Go Martin None A-8-B 8* Radio Operator Pvt, W, Yf, Kimbel None A-8-B 9. Engineer S/Sgt, C, H, Jones None A-8-B .0. Flight Engineer 1st Lt. R, M, Hoover None A-8-B Condensed Log of Flight Duration Elevations Highest elevation 35,000 feet Hrs, Uin. 5 30,000 - 3U,000 feet 19 35,000 feet ~2T over 30,000 feet Results 7. Radio Operator, Martin lo min. 35,000 feet Ache in thumb joint* 10* Flight Engineer, Hoover 6 min* 35,000 feet Coughing. The other eight men had no symptoms. Summary: No interference with mission* MAMU FLIGHT NOo 55 Wednesday, October lit, 19i±2, i'rom 5:50 to 6:50 p.ra. (1°) Squadron U2ii, Crew 7, Flight C * Decompression Mask 1, Pilot 1st. Lt« W, R. Harpster None Drinker 2* Pilot 2nd Lt. R. F. Miller None Drinker 3. Navigator 1st Lt, H, A. Thayer None B, Demand U* Bombardier 2nd Lt. M. G, Deer, Jr, None B.» Demand Rebr* 5. Tail Gunner Sgt. J, E. Michalak None A-8-B 6, Radio Opr. Gunner Sgt. C. J, Whalen None a-8-B 7* Engineer S/Sgt, R. C, Lundy None A-8-B 8-. Engineer ' S/Sgto G, K. Martin None A-8-B 9. Sgt. L, M, McKee None A-8-B 10o S/Sgt. J. C. Gibbons None A-8-B 3.1* Operations Off, Capte H. E, Jones, Jr, None B, Demand Duration iSlevations Highest elevation U0,000 feet Hrs. Min© 5 30,000 - 3U,000 feet 30 35,000 - 39,000 feet 1 UOjOOO feet ~~w over 30,000 feet Condensed Log of Flight Results 8. Engineer, Martin 3 rain, 35,000 feet Color not good, 11c Operations Off.. Jones 29 rain, 35-UO,000 feet Pain right arm (1*0,000), 29i 11 35-UO,000 11 Pain bad; color bad (35,000), 3h ” 30-1*0,000 fl Came down (30,000), Emergency mask on, 20,000 ,f Put demand on again. 5,000 " Coming down, looks better. The other nine men had no symptoms. Summary: No interference with mission except to lower elevation by about 5,000 feet. MAMU FLIGHT NO® 56 Thursday, October 15, 19E2, from 7:1*0 a.m. to 10:20 a.m, (2°E0‘) Squadron 372, Crew 5>, Flight B Decompression Mask 1. Pilot Lt, J. R. Boyd 2. Pilot 1st Lt, P. L. Veith None Be Demand Rebr* 3, Co-Pilot 1st Lt, I. i.u Osborne None A-8-3 U« Navigator 2nd Lt0 L. a. Kozov None Be Demand Rebr» 5. Bombardier 2nd Lt* M# L* Cypress 6, Tail Gunner S/Sgto G, Smith None A-8-B 7. Radio Operator Pvt, W* W. Kimbel None A-8-B 0. Radio Operator T/Sgt0 H. G, martin None A-8-B 9* Engineer S/Sgt,, C. Ho Jones None A-8-3 10, Flight Engineer 1st Lt, R. Hoover None A-8-B Duration Condensed Log of Flight Hrs® Min* Elevations Highest elevation 1*1,500 feet 28 30,000 - 3U,000 feet 1 31 35*000 - 39,000 feet 2 1*0,000 - 1*1,500 feet 2 1 over 30,000 feet lo Pilot, Boyd - Did not go up* 2. Pilot, Veith 1 min* 35,000 feet Pain left hand* 3* Co-Pilot, Osborne 22 min* 35,000 feet Pain right ankle, rubbing it© 58 11 35,000 11 Pain right ankle and up to knee. 1 hr© feet Pain much worse knee (1*0,000). 1 11 1 ,f 35-Ul,500 11 Pain much worse (kl,500); started down in air- lock. 25.000 feet Pain gone in air-lock. Went down at 9:07 and denitrogenized 9? 17 to 902 at k mi./hr. Went up again and no further trouble. k# Navigator, Kozov 29 min© 35,000 feet Pain right arm. 5* Bombardier, Cypress - Did not go up. 8. Radio Operator, Martin 30.000 feet Cold sweat after holding breath a bit. 27.000 n Feels better. 27 min. 35,000 ,f Pain right hand. 33 ,f 35,000 M Emergency oxygen mask on. 3k " 35,000 11 Down in air-lock. On exercycle 30 min. and went back in chamber© 17 11 35,000 ,f Bad pain in wrist. 27 11 30-35,000 feet Wrist very bad. 2i*,000 ” Pain gone* 7* Radio Operator, Kimbel 1 hr. kl min© feet Chilly all over (35,000). 10, Flight Engineer, Hoover 1 hr. 28 min© 35-El,500 feet Bends severe left leg (35,000). 1 hr. 30 11 35-kl,500 n Down ih air-lock© The other three men had no symptoms. Results Summary: Co-Pilot, Radio Operator and Flight Engineer incapacitated. Mission undoubtedly would have to be abandoned® MA.MU FLIGHT NO. 37 Thursday, October a.m. to 1:2U p.m. (2°30') Squadron U2i;» Crew 7, Flight C Decompress j.on Mask 1, Pilot 2nd Lt, R, F. killer None A-6-B 2, Navigator 1st Lt, H, A, Thayer None A-b-B 3« Bombardier 2nd Lt. M, G, Deer, Jr, None A-fi-B lu Tail Gunner Sgt» J, Michalsk None Demand .Rebr, 5. Radio Opr* Gunner G, J, YJhalen None Demand Rebr, 6. Engineer S/rgt. H, C, Lundy None 7» Engineer. S/Sgt. G* K* Martin None Drinker 8. L« M» McKee None A-6-B 9. S/Sgt* J, C. Gibbons 10* Operations Off, Capt* H. Ea Jones, Jr. 30 min, exercycle Demand & ii-8-B Duration Elevations Highest elevation U0,000 feet Hrs. Min. 35 30,000 - 3h>000 feet I 1*8 35,000 - 39,000 feet ho U0;000 feet 2 ~2T over 30,000 feet Condensed Log of Flight 1. Pilot, Miller 16 min# 33,000 feet Pain right leg just below knee* 1 hr* 9 11 23-33,000 feet Severe pain legs; very pale (30,000)* 1 hr, 13 11 23-33,000 “ Does not want to go up to U0,000 so coming down in air lock* *2* Navigator, Thayer min* 33,000 feet Coughing; chokes. 30.000 11 In air-lock; still coughing. 3* Bombardier, Deer 1 hr. lit min. 30-33,000 feet At 30,000 pain right knee* 7» Engineer, Martin 3h min* 33,000 feet Pain right knee. 28.000 ” Pain gone* 9# Gibbons - Did not go up because of cold. 10. Operations Off., Jones 16 min* 33,000 feet Changed to A-8-B mask. The other four men had no symptoms. Results Summary: Pilot could not go above 35,000 or even remain there. Navigator incapaci tated with chokes. Mission seriously interfered with. * His attack of chokes was quite severe but relieved as soon as he reached ground, without much after effect. In an actual flight ten days ago developed a similar cough at 32,000 feet. As the plane was then on the way down no serious symptoms continued and the coughing stopped when they reached 25,000 in about 30 minutes. This subject seems susceptible to mild chokes. Whether or not they would become severe chokes is not known. MAMU FLIGHT NO, 58 Thursday, October 15, 19U2, from p.m. to U;12 p.m. (2°26f) Squadron 370, Cre2 6, Flight B It Pilot 2nd Lt. B, E. Flahauen Decompression None Mask Demand 2. Co-Pilot 2nd Lt© J* H. Ralph None a-8-B 3. Bombardier 2nd Lt« k. Payton None A-8-B h. Tail Gunner Sgt. D, J, Potter None A-8-B Aerial Engineer S/Sgt0 J, W» nnderson None A-8-B 6« Radio Operator S/Sgt-, S, W* Naperkoski None Demand Rebt* 7c Aerial Engineer S/Sgta J. M© Faulkenberg None A-8-B Condensed Log of Flight Duration Hr. Min. Elevations Highest elevation 39*000 feet 37 30,000 - 3M°° feet 53 35,000 - 39,000 « 1 30 over 30,000 feet 3« Bombardier, Payton h9 nirio 35,000 - 37,000 feet Pain left wrist (37,000)* 51 “ 35,000 - 39,000 »» Pain left wrist severe (39,000)t 311.000 feet Pain better 30.000 ,f Pain gone0 6c Radio Operator, Naperkoski 13 min0 35,000 feet Emergency button on* The other five men had no symptoms. Results Summary: No interference with mission. MAMU FLIGHT NO. 59 Thursday, October 15, from hs2l4.'p.m. to 7:01 p.m# (2°27’) Squadron 371, Crew 6, Flight S Decom. ness ion Mask 1# Pilot 2nd Lt, J. H. McClendon None Demand Refer. 2. Pilot Lt. W. R. Harpster 30 mine. 3 mi./hr3 A-8-B 3. Co-Pilot 2nd Lt. C. H. Miller None Demand U, Bombardier Lt« W. Steele 5, Navigator 2nd Lt. W. J. Stickle None 6 c* Tail Gunner S/Sgt. W, Jo Pash None A-8-B 7 > Waist Gunner S/Sgt» R. W. Vaughn None A-8-B 8* Upper Gunner S/Sgt. H, D. Dillon None A-8-B 9o Radio Operator S/Sgt<. C. C* Hatton None A-8-B 10, Asst. Radio Opr* S/Sgt, R. L. Hopkins None A-8-B Condensed Log of Flight Duration Elevations Highest elevation U2,000 feet Hr. Min. 7 30,000 - 3U,000 feet l uu 35,000 - 39,000 »» 2 U0,000 - Ul.000 « 1 53 over 30,000 feet Results 1# Pilot, McClendon 3U mini 35,000 feet Pain right shoulder slight (35,000)# 3U n 35,000 11 Emergency oxygen on# 38 n feet Pain worse (U2,000). iiU u 35-1*2,000 w Pain about the same (35,000). 1 hr. 2h 11 35-U2,000 11 Pain shoulder gone (35,000)# ii. Bombardier, Steele - Did not go up because of cold# 5# Navigator, Stickle 37 min# 35~U0,000 feet Had elbow resting on knee# Knee felt tingling when took elbow off# Got worse gradually (U0,000). 50 ,f fl Pain knee very bad (35,000). Started down in air lock# The other seven men had no symptoms# Summary: Pilot had severe bends but stuck it out for one and a half hours,- Navigator incapacitated in 50 minutes. Mission seriously handicapped. MAMU FLIGHT NO. 60 Friday, October 16, 19U2, from 709 a,m, to 10*.C9 a,m, (2°30•) Squadron 370, Crew 6, Flight B Decompr* 5ss ion Mask 1. Pilot 2nd Lt, B« E# Flahauen None 2. Co-Pilot 2nd It® J* H* Ralph 28 min* 3 miw/hr3 Demand Rebr, 3. Bombardier 2nd Lt, m* Payton 28 min* 3 mio/hr* Drinker U* Tail Gunner Sgt* D, J. Potter 20 min0 exercycle A-8-B Aerial Engineer S/Ggt* J* W* Anderson None Demand 60 Radio Operator S/Sgt. S, W. Naperkoski None A-8-B ?• Aerial Engineer S/Sgt. J. a. Faulkenberg None Demand Rebr« Condensed Log of Flight Duration Elevations Highest elevation U0,000 feet Hrs • Min. h 30,000 - 3U,000 feet 1 58 35,000 - 39,000 « 7 U0?000 feet 2 9 over 30,000 feet Results 5># serial Engineer, Anderson 1 hr* - U0,000 feet Tremor hands The other six men had no symptoms* Summary; No interference with mission. MAMU FLIGHT NO. 6l Friday, October 16, 19U2, from 10:37 a.m, to 1:13 p.m# (2°36!) Squadron 371, Crew 6, Flight B Decompression Mask 1# Pilot 2nd Lt • J. H. McClendon None iV-5-B 2. Co-Pilot 2nd Lt , C, H. Miller None A-8-B 3. Bombardier Lt. V. Steele h. Navigator Lt. H. A. Thayer 30 min. exercycle Drinker Rebr* 5. Navigator Lt, W. J• Stickle 30 min. 3 mi./hr. A-8-B 6. Tail Gunner S/Sgt. V/, J, Pash None Drinker 7. Waist Gunner S/Sgt. R, W. Vaughn None Drinker 8. Upper Turret S/Sgt. H» D, Dillon None Drinker 9. Radio Operator S/Sgt, C. C, Hatton None Demand Rebr. 10. iksst. Radio Operator S/Sgt, R, L. Hopkins None Demand Condensed Log of Flight Duration Elevations Highest elevation 35*000 feet. Hr, Min* 20 30,000 - 3U,000 feet 1 35 35*000 feet I 5? over 30,000 feet Results 3» Bombardier, Steele - Did not go up because of cold* 6# Tail Gunner, Pash ’"’ThTmin# 35,000 feet Very cyanosed; felt sleepy# 7# Waist Gunner, Vaughn a6 min# 35,000 feet Emergency button on# 10# Asst. Radio Operator, Hopkins, 58 min# 35,000 feet Pain left knee severe# 35,000 •» Came down; much better# The other six men had no symptoms# Summary: Radio Operator severe but not incapacitating bends# Mission of about two hours not interfered with* MAMU FLIGHT NO* 62 Friday, October 16, 19h2, from U: 1U p«m*"to 505 p.m. (l021’) Squadron 372, Crew 6, Flight B 1* Navigator 1st Lt. H. Thayer Decompression None Mask A-U-B 2. Pilot 2nd Lt, L, H. Scholar None Demand Rebr. 3. Co-Pilot 2nd Lt, J, E, Stay None Drinker U. Navigator 2nd Lt, C. L. Seymour None Demand Rebr. 5. Bombardier 2nd Lt. R. P. Ortiz None Demand Rebr. 6* Radio Operator S/Sgt. H. P. Rosenberg None a-8-B 7. Tail Gunner S/Sgt. D. F. Morgan None a-8-B 8. Upper Turret Gunner S/Sgt. P. F, Jurgensmier None a-8-B 9• Bottom Turret Gunner S/Sgt. V. R, Lehman None A-8-B 10. Engineer S/Sgt, J. F. Durden None A-8-B Duration Elevations Highest elevation 35,000 feet. Hr, Min. 38 30,000 - 3U,000 feet 13 35,000 feet “TT over 30,000 feet Condensed Log of Flight Results 2. Co-Pilot. Stay 0 min. 3$,000 feet Oxygen tube off, on right away. 10 n 35,000 n Pain right shoulder, slight. ill 11 35,000 11 Pain right shoulder severe* 17 « 30-35,000 feet Pain right fingers,wrist, elbow, shoulder, (30,000). 28 n 30-35,000 n Down in air-lock. 3. Navigator, Seymour 1 Klin* 35,000 feet Slight gas pains. 26,500 ,f Better. Ill u 26,500-35,000 Gas pains severe* U7 n 26,500-35,000 Pain left wrist, elbow and shoulder* 10. Engineer, Durden 8 min* 35,000 feet Bad gas pains* 10 ,f 35,000 11 Entered air-lock* The other seven men had no symptoms* Summary: Co-Pilot and Engineer incapacitated and mission interfered with. 1» Navigator, Thayer - Stayed over to do another run* Flight 55 - No symptoms: no decompression* M 57 - Severe bends. Came down in air-lock* No decompression* ” 62 - No symptoms. MAMU FLIGHT NO. 63 Friday, October 16, 19U2 from 5**U7 p.m* to 6:U6 p.m, (59’) Squadron U2U, Crew U, Flight B 1. Pilot 1st Lt. J. R. Boyd 21 min. 3 mij/hr© Mask Bj Demand 2. Pilot 1st Lt. H. L . Milledge None a-8~B 3. Co-Pilot 2nd Lt. S. L. Burke None Drinker h. Navigator 2nd Lt. J. K> Woody None B. Demand 5. 2nd Lt. C, T. O’Neill None Drinker 6. Radio Operator S/Sgt« M. H. Smith None A-8-B 7. Radio Gunner S/Sgt. R. V/. Burchette None a-8-B 8. Waist Gunner Sgtc LI. E, Smith None A-8-B 9* Upper Turret S/Sgt, N. K. Bullard None A-8-B 10 o Extra S/Sgt« W, M. Ward None a-8-B 11. Extra Sgt» J. V. Shaughnessy None A-8-B 12. Flight Surgeon Capt, J. R. Glasscock None B. Demand *13. Navigator 1st Lt. H. A. Thayer None A-8-B Duration r '■ Elevations Highest elevation U2,000 feet 6 nin- 20 nin. 7 nin. 30.000 - 3h,000 feet 35.000 - 39,000 feet U0,000 - Ul,000 feet 33 nin. over feet Condensed Log of Flight Results 1* Pilot, Boyd 3 min* U2,000 feet Gas pains not bad* .0, Extra, Ward 15 min* 35-U2,000 feet Cyanosisj tremor (h2,000) 35-U2,000 feet Still shaky (35,000) The other 11 men had no symptoms* Summary: Short mission of 33 min* above 30,000 not interfered with* * Thayer - Flight 55, 57, 62, 63 Had trouble on flight 57 - came down in air lock* No trouble on other 3 flights* MAMU FLIGHT NO. 61* Saturday, October 17, 19U2 from 7:39 a.ra. to 10:27 a.m. (20l*8l) Squadron 372, Crew 6, Flight B 1. Pilot 2nd Lt. L* H* Scholar D e compres2ion Misk None A-b-B 2. Co-Pilot 2nd Lt. J. E. Stay 22 min. exercycle A-8-B 3. Navigator 2nd Lt. C« L. Seymour 22 min* 3 mi./hr* A-8-B U* Bombardier 2nd Lt, R. P. Grtiz None a-8-B So Radio Operator S/Sgt. H. P. Rosenberg None B ©Demand Rebr ? 6. Tail Gunner 3/Sgt* D« F. Morgan None B©Demand Rebr© 7. Upper Turret Gunner S/Sgt. P. F. Jurgensnier None Drinker 8 6 Bottom Turret Gunner S/Sgt. V, R# Lehman None B.Demand 9. Engineer S/Sgt. J. F. Durden 22 min* mi./hr.A-8-B Condensed Log of Flight Duration Elevations Highest elevation UU,300 feet* Hr. Min* £0 30,000 - 3U,000 feet 1 8 35,000 - 39,000 " 6 U0,000 - Ul,000 « 2 U2,000 feet 2 6 over 30,000 feet Results 2* Co-Pilot, Stay 1 hr* 11 min* 30,000 - 1*2,000 feet Pain right wrist (1*2,000), 3* Navigator, Seymour 3 min* 30,000 - 35,000 feet Bad gas pains (35,000). 9 M 30,000 - 35,000 ” Gas pains better (30,000). 6* Tail Gunner, Morgan 1 hr, 53 min* 3°,000 - 1*2,000 feet Little pain left knee (35,000). 2 11 1 " 30,000 - 1*2,000 « Still has pain (1*2,000). 1*0,000 feet Pain gone, 7. Upper Turret Gunner, Jurgensmier 30,000 feet- Very cyanosed; flow up, better, 52 min* 30,000 - 35,000 feet Suddenly became very cyanotic and dizzy (30,000), 1 hr, 51 11 30,000 - 1*2,000 M Pain right knee (35,000), The other five men had no symptoms* Summary: Difficulty with oxygen apparatus but no severe bends* Mission of over two hours carried out* MAMU FLIGHT NO, 6$ Saturday, October 177~I^E^^ronTlIJi37~a Demand 2. Co-Pilot 2nd Lt.'W. C. Sharkey None B. Demand 3. Navigator 2nd Lt. G. T. White None • h. Bombardier 2nd Lt. I. F. Teykl None B, Demand 5. Radio Operator S/Sgt. R, D. Copeland None A-8-B 6. Radio Opr.-Gunner S/Sgt. R. A, Fale None a-O-B 7. Tail Gunner S/Sgt. A. R. Creach None 8. Engineer S/Sgt. E, W. Ericson None Drinker 9. Asst. Engineer S/Sgt. C, J, Atkinson None A-8-B .0. Operations Off, 1st Lt, W. R, Harpster None a-8-B Condensed Log of Flight Duration Elevations Highest Elevation k0,000 feet Hr* Min. 5 30,000 - 3k,000 feet 20 3^3000 - 39,000 feet h U0,000 feet 29 over 30,000 feet Results 1, Pilot, Lundby - Did not go up, 7# Tail Gunner, Creach - Did not go up. No member of the group had symptoms. Summary; Mission carried out. MAYO AERO MEDICAL UNIT MEMORANDUM REPORT to ARMY AIR FORCES MATERIEL CENTER Under Contract No* W£35ac-25829 SUBJECT: Conservation of oxygen affected by the use of economizer bag, and with and without the use of the autoraix* SERIAL REPORT: Series A, No. 3 DATE: November 20, 19h2 An Purposes. li To demonstrate that the economy of oxygen is substantial when an economizer bag is attached to the inspiratory tube. This economy is demonstrated with the automix set for either ”on” or 11 off.” 2* To confirm the econony of oxygen effected by use of the automix. 3* To demonstrate that the air-oxygen demand regulator when constructed so as to deliver the theoretically Correct mixture, according to specification, functions perfectly both with and without the use of the economizer bag. B„ Factual data* 1. Method and apparatus. a* The economizer bag made of rubber (although other materials may be used) has a maximum volume of approximately 650 cc. when fully distended. Since it usually was not fully distended the effected volume was approximately 550 cc. The bag was attached to the corrugated tubing directly below the mask. In some instances it may be advisable to attach the economizer bag directly to the demand regulator. If this is done the optimal size of the bag should be such that its maximum volume is approximately U25 cc., thus avoiding the increased COg concentration which occurs with the use of a larger economiser bag attached to the regulator. b, In the accumulation of these data Aro Products demand regulator #U902 was used. c. During each series of observations the subject was sitting upright and remained substantially inactive. The subject wore a demand type mask (a-10 or A-lU) carefully fitted and checked at each observation by the Scholander method of gas analysis. Samples were taken from both the mask and the inspiratory tube near the demand valve mask to insure against the possibility of the slightest leakage around the mask invalidating the quantitNative results obtained in regard to the value of an economizer bag. d. At each altitude a measured amount of oxygen was used (l) without the economizer bag, automix off, (2) without the economizer bag, automix on, (3) with the economizer bag, automix off, and (U) with the economizer bag, automix on. e. The oxygen used was measured by noting the time required for the subject to inhale from a small tank sufficient oxygen to cause a drop in pressure of 100 lbs. Our apparatus, on careful calibration at qll altitudes, showed that a drop in pressure of 100 lbs. represented a volume of A. 29 liters, S.T.P.D. f. Six subjects, (Table l) of various statures were used in making a total of nine series of observations. Table 1. Sex, height and weight of subjects. Subject Sex Height in in. Weight in lbs. William Burrows M 70 157“ Rita Schmelzer F 62 lid* Eleanor Larson F 67 111 Lucille Cronin F 62 156 Alvin Sweeney M 69 165 Henrietta Cranston . : * 62 100 2c. The data obtained in these nine series of observations, expressed as average figures, is summarized in Tables 2 and 3 where the oxygen used at various altitudes is expressed in liters per minute S.T.P.D. in Table 2, and liters per minute lung volume (ambient bar., 37° C. Sat.) in Table 3* Charts I and II graphically illustrate the same data as expressed in Tables 2 and 3 respectively. Table 2, Oxygen used expressed in liters per minute, S.T.P.D, i 2 3 h in Without economizer tag With economizer bag Thousands '.Autoihix Automix Automix Automix of Feet off on off on 15,000 3.U0 1.19 2.17 .69 25,000 2.23 I06U 1.38 1.06 30,000 1.71 1.71 1.05 1.06 33,000 1.37 1,1*0 •91 .91 Table 3# Oxygen used expressed in liters per minute lung volume (ambient bar. 37° C, Sat.) 1 2 3 —c Altitude in Without economizer bag With economizer bag Thousands Automix Automix Automix Automix of Feet off on off on l5,000 7.6F~ 2M a,9i 1.56 25,000 8.20 6.03 5.08 3*88 30,000 8.27 8,27 5-09..V 5*u 33,000 7.92 8ol0 5.26 5.27 The great economy in the use of oxygen effected by the economizer bag may be seen in a comparison drawn between columns 1 and 3 (Tables 2 and 3)* This comparison shows the oxygen waste without the economizer bag, aitomix off, using as our standard of efficiency the amount of osygen used -with the economizer bag attached and automix off. In like manner a comparison may be drawn between columns 2 and U (Tables 2 and 3) to demonstrate the oxygen waste without the economizer bag* automix on* using as our standard of efficiency the amount of oxygen used with the economizer bag attached, automix om The data in Tables 2 and 3 are graphically presented in Charts 1 and 2 respectively, -where it can be seen at a glance that if an economizer bag is not used one wastes a significant amount of oxygen corresponding to between 50 and 75 per cent of the oxygen used with an economizer bag as shown in Table U. Table lu Percentage waste oxygen without the economizer bag as compared with oxygen used when the economizer bag is attached. 1 2 Altitude in Percentage Percentage Thousands with auto- with auto- of Feet mix off mix on l5,000 56 ~TT" 25,000 63 57 30,000 66 67 33,000 5i 5U Table h shows the percentage waste of oxygen runs between 5>1 and 75 per cent tjy neglecting to use an economizer bag. The percentage figures in Table U, column 1, for automix off are obtained from either Table 2 or Table 3 as follows; Col, 1 - Colo 3 . Col. 3 The percentage figures in Table h, column 2, for automix on are obtained from either Table 2 or Table 3 as follows; Colo 2 - Col, U. —Cam; Table 5. Percentage oxygen in inspired mixture coning from oxygen tank ■when using automix with and without economizer bag. Altitude in Thousands of Feet 1 2 3 Percentage oxygen needed from oxygen tank in inspired mixture (8,37° C, Sat,) to maintain a strictly normal alveolar oxygen pressure Percentage oxygen used frorr tank in inspired mixture (B.370 C.Sat.) as determined by comparison of columns 1 and 2, and columns 3 and Ij., Table 3. Without econ- omizer bag With econo- mizer bag 15,000 23.0 35.0 31.1* 25,000 5U.0 7i*.7 76.6 30,000 79.0 100.0 99. U 33,000 100,0 102.5 100 o 3 The data obtained, as expressed in Table 5, demonstrate two facts: (l) That at any altitude the proportion of air-oxygen furnished by use of the automix is practically identical whether the extra economy of an economizer bag is or is not taken advantage of; stated differently, the economizer bag does not disturb the relationship of the air-oxygen automix mechanism* (2) That the particular demand regulator (Aro Products #U902) used in those observations is seen to deliver roughly from 10 to 20 percentage points more oxygen than necessary for the achievement of the sea-level alveolar oxygen pressure; that is, there is a slight excess of oxygen* This discrepancy is on the safe side and, therefore, permissible; a discrepancy of similar amount, if it lowered the proportion of oxygen in the mixture, would not be permissible. Table 6, Percentage in inspired mixture. Altitude in Thousands of Feet 1 2 3 Allowable percentage of nitrogen in inspired mix- ture so that the partial pressure of oxygen in the alveolar will be normal Percentage nitrogen as determined by Scholander gas analysis of sample taken from tube with auto- mix on. Without economizer bag With economizer bfS 15,000 61.0 ~^6 25,000 36.6 23 2S 30,000 16,7 1 1 33,000 0,-0 0 1 Table 6 represents a slightly different method of fexpressing the same data. Column 1 represents the amount of nitrogen from the addition of air •which can be present in the mixture from the automix which when inspired will maintain a normal alveolar oxygen pressure. It may be seen in columns 2 and 3 (Table 6) that the percent of nitrogen delivered by the automix never exceeded the allowable amount and usually was between 5 and 15 percentage points lower than necessary to maintain a normal alveolar oxygen pressure. The use of the economizer bag does not disturb the proper functioning of the automix mechanism. C. Conclusions. 1. Waste in the use of oxygen without the use of an economizer bag ranges from 50 to 75 per cent; thus, the use of the economizer bag materially increases oxygen economy. 2. The economy of oxygen effected by the use of the automix is confirmed. This economy is enhanced by the use of the economizer bag. 3. The use of the economizer bag does not interfere with the functioning of the air-oxygen partition mechanism of the automix demand regulator here used and this would apply to any automix regulator in good condition. lu An important wby-product” obtained by the use of an economizer bag in conjunction with the demand system is that the recently developed demand type mask (A-10 or A-lIt) can be used with a constant flow regulator like the Pioneer if a simple adaptor is supplied. This interchangeability is of great advantage because the. Pioneer constant flow regulator is now widely distributed all over the world, 'S' and if the economizer bag is on the demand mask it allows the mask to be used no matter whether a constant flow regulator or a demand regulator is in any particular airplane* For most conditions it is best to have the economizer bag attached to the tubing just below the mask; however, under certain conditions it may be advisable to have the economizer bag attached to the regulator itself by a special T-tube* The economizer bag need not be made of rubber as some type of pliable plastic or silk-like material may be used* D * Recommendations• 1* That an economizer bag be used in conjunction with the autonix demand regulator: a. to conserve oxygen over and above the conservation produced by the autoraix mechanism, and b, to enable the utilization of the recently developed demand type masks lA-10 or A-lU) in airplanes equipped with the present issue of Pioneer constant flow regulator as well as with the demand type regulator now being issued; therefore, a'simple adaptor Should be available which would render easy interchange* Experimental work done by: 1st Lt. Charles B. Taylor 2nd Lt. John P. Mar Larger Liaison Officers from the Air Surgeon's Office In cooperation with; Dr* Bernard P. Cunningham Dr. Francis J* Robinson Dr. iklvin R. Sweeney Dr, Kenneth G, YTilson of the Mcy o Aero Medical Unit Approved by: Walter M, Boothby, M« D, Chairman, Mayo Aero Medical Unit CONSERVATION OF OXYGEN ALTITUDE IN THOUSAND FEET Chart I Mayo Aero Medical Unit Nov. 18, 19U3 Revised Dec. 19U6 LITERS OF OXYGEN USED S.T.P.D. - ?60 ram. Hg. 0°C., dry Economizer Bag on Tube - Effective Volume = 550 cc« Aro Products Demand Regulator - #U902 BAROMETRIC PRESSURE - mm. Hg. Chart XVIII - 1 W.M.Boothby and B.P.Cunninghagi CONSERVATION OF OXYGEN ALTITUDE IN THOUSAND FEET Chart II LITERS OF OXYGEN (Ambient Bar,, 37°C., LUNG CONDITIONS Mayo Aero Medical Unit Nov, 19U2 Revised Dec* 19U6 BAROMETRIC PRESSURE - MM. Hg. XVIII-2 W,M*.Boothby and B.P.Cunningham Chart I Volume of oxygen is eoqpreased. as liter* jper minute S,T,P,D, throughout Chart I, Curve I represents the volume of oxygen used without the economizer bag, autoraix off. Curve II represents the volume of oxygen used with the economizer bag attached to the tube below the mask and with automix off. Curve III represents the volume of oxygen used without the economizer bag, automix on. Curve IV represents the volume of oxygen used with the economizer bag attached to the tube below the mask, and with automix on. Chart II Chart II is an expression of the same data converted to represent oxygen in liters per minute lung volume (Ambient bar, 37° C, Sat,), Curve I shows the volume of oxygen used without the economizer bag, autoraix off. Curve II shows the volume of oxygen used with the economizer bag attached to the tube below the mask, and with automix off. Curve III shows the volume of oxygen used without the economizer bag, automix on. Curve IV shows the volume of oxygen used with the economizer bag attached to the tube below the mask, and with automix on. ALTITUDE 3£,000 FEET Aro Products demand regulator #U902 and Bulbulian #lU demand type mask were used throughout. The economizer bag, maximum volume 650 cc., average volume 550 cc,, was attached to corrugated tube just below the mask WITHOUT ECONOMIZER BAG Automix on Automix Off Ambient 37°Sat, L./Min. STFD L,Mn, From tank 02% Scholander Ambient Tube Mask 37°Sat, 09% 09% L./Min. Scholander STPD Tube Mask L./Min, 09% 09% Column No,; 1 2 3 h 5 6 7 9 No, io Date xi=C^Il2 Subiect Schmelzer 2.1*7 1.09 33 1+1+ 7.1+6 3.30 99.9 99-5 2e 11-3-1*2 Larson 2.33 1.03 32 1+5 7.19 3.18 99.1* 99 e0 3. 11-3-1+2 Cronin 2.85 1.26 1+2 1+6 6.92 3.06 99.9 99.8 h. 11-2-1*2 Cranston 1.97 .87 37 1+3 5.29 2.3U 99.8 99.5 10-30-1*2 Schmelzer 2,13 .91+ 27 1+7 7.76 3.1*3 100*0 98,8 6. 10-30-1+2 Sweeney 3.08 1.36 38 1+2 8.21 3.63 99.9 99.3 7. 10-28-1*2 Tulare 3.96 1.75 36 1+1+ 10«93 1*.83 99.0 Average: 2.68 1.19 35 1+1+ 7.68 3.1*0 99.7 99.3 WITH ECONOMIZER BaG ON CORRUGATED TUBING Automix on Automix off Ambient" 37°Sat. L./Min. STPD L./Min. From schoiander Ambient tank Tube Mask 37°Sat. ®2% 02% 0?% L./min* STPD L./Min. Scholander Tube Mask 0 2% 0n% Column No.; 10 11 12 13 ll* 15 “IT” 17 ~iT Noc Date Subject lo 11^1*3*2 Schmelzer 1.1*9 .66 28 1*3 5.27 2.33 99.9 99*2 2. 11-3-1*2 Larson lell .1*9 25 1*2 l*.3 9 1.91* 99.5 99 iO 3« 11-3-1*2 Cronin 1.72 .76 33 1*0 5.18 2.29 99.9 99,6 U. 11-2-1*2 Cranston 1.01* .1*6 28 35 3.66 1.62 99.8 99.0 5- 10-30-1*2 Schmelzer 1.90 .81* 3U 1*7 5.51* 2.1*5 99.9 99.7 6, 10-30-1*2 Sweeney 1,63 • 72 36 35 U.59 2.03 99.9 98-0 7o 10-28-1*2 Tulare 2.06 .91 36 36 5.75 2.51* 99»9 Average: 1.56 .69 31.1* 1*0 l*.91 2.17 99.8 99.1 , ABOVE DATA EXPRESSED AS PERCENTAGE WASTE OF OXYGEN Barce^tagc' waste Oo Percentage waste O2 Percentage waste Og without, econoaizor with automix off without economizer Autoniix Automix With Without bag, automix off On Off Economizer Economizer Col. 2-11 Col.7-16 Col. 16-11 Col. 7-2 Col. 7-11 No, Date Subject 11 "HT” 11 2 11 1, 11-1*-1*2 Schmelzer 66 IT 251* 202 liOO 2. 11-3-1*2 Larson 110 6U 29$ 209 $1*9 3. 11-3-1*2 Cronin 66 3h 201 1U3 303 h. 11-2-1*2 Cranston 89 U5 2$2 169 1*09 5. 10-30-U2 Schnelzer 12 ho 192 261; 308 6, IO-3O-U2 Sweeney 89 19 182 167 hOh 7« 10-28-1*2 Tulare 9 2 90 179 176 U31 Average: 75 56 222 190 1*01 ALTITUDE 25*. 000 FEET Aro Products demand regulator #1*902 and Bulbulian #ll* demand type mask were used throughout* The economizer bag, maximum volume 650 cc., average volume 550 cc., was attached to corrugated tube just below the mask WITHOUT ECONOMIZER BAG Automix on Automix off Ambieni From Scholander Ambient Scholander 37°Sat. STPD tank Tube Mask 37°Sat. STPD Tube Mask L./Min. L./Min, Of 0?% 09% L./Min. L./Min. 0?$ Column: 1 2 3 . u 5 6 ... 7- 8 No, Date Subject 1. 10-29-U2 Burrows 6.32 1.72 73 7U 8.68 2.36 99.7 99.5 2c 11-2-U2 Cranston 5.33 1.U5 76 Ih 7.02 1.91 99.5 99o2 3. 10-28-U2 Tulare 8.75 2.38 67 78 13.16 3.58 99.9 h. 10-30-U2 Sweeney U.71 1.28 5U 76 8.75 2.38 99.9 99.2 5. 10-30-U2 Schmelzer 5.73 1.56 78 78 7.32 1.99 99.2 97.0 6. 11-3-U2 Cronin 6.U3 1.75 89 81 7.20 1.96 99o9 99.U 7o 11-3-U2 Larson 5.37 1.U6 82 77 6.5U 1.78 99.8 98.0 8. 11-U-U2 Schmelzer 5.33 i.l»5 69 78 7.68 2.09 99.9 99.2 9a 11-2-1(2 Schmelzer 6.29 1.71 8U 77 7.U6 2.03 99.8 99.U Average: 6.03 1.6U 7U.7 77 8.20 2.23 99.7 98.9 WITH ECONOMIZER BAG ON CORRUGATED TUBING Automix on Automix off Ambient 37°Sat. L./Min. STPD L./Min, From Scholander Ambient tank Tube Mask 37°Sat, 02% 02% L./Min. Scholander STPD Tube Mask L./Min, 02% 02% Column: 10 11 12 13 15 16 17 18^ TToT bate Subject 1 c 1 0-29-U2 Burrows u.o8 1.11 76 78 78 5cUU 1.1*8 99.8 99.6 2* 11-2-1*2 Cranston 2.87 .78 8U 73 3.U2 .93 99.6 99.1* 3o 10-28-1(2 Tulare 5.66 1.5U 85 72 6.65 1.81 99.8 h. 10-30-U2 Sweeney 3.12 .85 70 73 U.U8 1.22 100 99.2 5. 10-30-U2 Schmelzer 3.57 .97 6? 75 5.33 1.1*5 99.9 99.0 6, 11-3-U2 Cronin U.Ul 1.20 85 80 5.16 1.U1 99.9 99.2 7. 11-3-1*2 Larson 3.71 1.01 76 75 U.89 1.33 99.5 98.5 8. 11-U-U2 Schmelzer 3.U6 •9h * 73 77 U.7U 1.29 99.9 99.2 9. 11-2-U2 Schmelzer U.oU 1.10 73 76 5.55 1.S1 100 99.5 Average: 3.88 1.06 76,6 75 5.08 1.38 99.8 99.2 ABOVE Data expressed as percentage waste of oxygen Percentage waste 0^ Percentage waste ©2 Percentage waste 0o without economizer with automix off without euonomizer Autonix Autonix With Without bag, automix off On Off Economizer Economizer Col. 2-11 Col. 7-36 Col. 16-11 Col. 7-2 Col. 7-11 No. Date Subject 11 "15“ 11 2 11 1. 10-29-12 Burrows 5$ 33 37 113 2. 1I-2-U2 Cranston 86 105 19 32 11(5 3. 10-28-1(2 Tulare 98 17 50 133 h. 10-30-1*2 Sweeney 51 95 hh 86 iso 5. 10-30-1*2 Schmelzer 61 37 h9 28 105 6. 11-3-1(2 Cronin U6 39 17 12 63 7* 11-3-1(2 Larson U5 3U 32 26 76 8. 11-U-U2 Schmelzer 5U 62 37 uu 122 9. 11-2-1(2 Schmelzer 56 3U 37 19 85 Average: 57 63 32 37 111* ALTITUDE 30,000 FbET Aro Products demand regulator #1*902 and Bulbulian #lL demand type mask were used throughout. The economizer bag, maximum volume 650 cc., average volume 550 cc., was attached to corrugated tube just below the mask. WITHOUT ECONOMIZER BAG Automix on Automix off Ambient 37°Sat„ L./Min, STPD L,/Min0 From tank o2% Scholander Ambient Tube Mask 37°Sat«, 0?$ O2$ L./Min« STPD L./Min. Scholander Tube Mask 02$ 02$ Column: 1 2 3 5 6 7 9 No, la Date n^H2 Subject Schmelzer 8.1*1 1.71* 101 98.0 8.31 1.72 99.9 99.8 2o 11-2-U2 Cranston 7.05 1.1*6 103 99.5 6086 1.1*2 99.8 99.0 3. 11-1*-1*2 Schraelzer 7.68 1.59 101 99.9 7.63 1.58 99.9 99.5 h. 11-3-1*2 Cronin 7.92 le6U 99 99.9 7.97 1.65 99.9 99.9 r> * 10-30-U2 Schmelzer 8.36 1.73 101 99.6 8.26 1.71 100. 99.9 6, 10-30-14.2 Sweeney 6,^2 1.35 80 99.7 8.12 1.68 99.9 99.2 7 « 10-28-U2 Tulare 12o27 2.5U 102 99.2 12o03 2.1*9 99.8 Bo 10-29-U2 Burrows 8.70 1.80 10? 99.9 8.12 I068 99.7 99,1* 9» 11-3-1*2 Larson 7.51* 1,56 106 99.7 7.10 1.1*7 99.5 99.0 Average: 8.27 1.71 100 99.5 8.27 1.71 99.8 99.5 WITH ECONOMIZER BAG ON CORRUGATED TUBING Automix on Automix Off Ambient 37°Sat, L./Min0 STPD Lc/Mih. From tank 0?% ccholander Ambient Tube Mask 37°Sat. 02% 02% L./Min* STPD Lo/Min0 Scholander Tube Mask 09% 09% Column; 10 Xx 12 . 13 -U+ .O lo - j. IT No- J- n Date 11^U2 Subject Schmelzer 5U46 1.13 100 99.8 9Ui6 1.13 99.9 99-8 2. 11-2-U2 Cranston 3.08 •6U 99 99.8 3.11 .6U 99,8 99,0 3. ll-l*-l*2 Schmelzer 5.27 1.09 98 99.9 5.36 1.11 99*9 98.,6 k. 11-3-U2 Cronin 5.22 1,08 101 99.3 5.17 1.07 99.9 97 oO r~> 10-30-U2' Schmelzer 5.07 1,0$ 101 99.8 5.02 i,oU 100. 99.6 6. 10-3O-U2 Sweeney 3.U3 • .71 89 99.9 U.06 08U 99.7 98,0 7 s 10-28-U2 Tulare 8,12 1.68 111; 99.8 7.10 1.1*7 99.8 8e 10-29-U2 Burrows 5.60 1,16 100 99.7 5. 60 lvl6 98.6 99.0 9o 11-3-1(2 Larson hold .99 97 92.8 I*.93 le02 99.7 97..S Average: 5.11 1.06 99ol* 99. 5.09 1.05 99.7 98.6 No* Date Subject Percentage waste O2 without economizer Automix Automix On Off Col* 2-11 Col*7-16 11 Percentage waste O2 Percentage waste Q2 with automix off without economizer With Without bag, automix off Economizer Economizer Col* 16-11 Col* 7-2 Colo 7-11 11 2 11 1* 11-2-1*2 Schmelzer 55 32 52 2* 11-2-1*2 Cranston 129 121 At altitudes of 30,000 123 3. 11-U-U2 S clime Iser 1*6 1*2 feet and over 100 per 1*5 lu 11-3-U2 Cronin 52 51* cent oxygen is delivered 53 10-30-1*2 Schmelzer 65 65 both with automix on and 63 6. 10-30-U2 Sweeney 90 100 off (Aro demand regulator 137 7. 10-28-1*2 Tulare 51 69 #1902). 1*8 8* 10-29-1*2 Burrows 55 1*5 1*5 9c 11-3-1*2 Larson 58 hh 1*9 Average: 67 66 68 ABOVE DATA EXPRESSED AS PERCENTAGE WASTE OF OXYGEN ALTITUDE 33,000 FEET Aro Products demand regulator #U902 and Bulbulian #1U detnand ty£e mask were used throughout* The economizer bag, maximum volume 690 cc., average volume 950 cc., was attached to corrugated tube just below the mask. WITHOUT ECONOMIZER BAG Automix on Automix off Ambient 37°Sat. L./Min. STPD L./Min. From tank 02% Scholander Tube Mask 02% 02% Ambient 37°Sat. L./Min. Scholander STPD Tube Mask L./Min. 02% 02% Column: 1 1“ T” 5 6 ir B 9 No. Date Subject 1, 10-29-U2 Burrows 8.69 i.5o in 99.5 7.82 1.35 99.5 99.0 2, 11-2-U2 Schmelzer 6.92 1.51* 100 99.8 8.92 1.5U 100 99.8 3* 11-3-1*2 Larson 7.1*2 1.28 97 99.5 7.65 1.32 99.5 99.7 10-30-U2 Schmelzer 8.17 i.l*i 99 99. .8 8.29 1.1*3 99.1* •99.9 11-3-1*2 Cronin 8.3U l.hh 102 99.9 8.17 1.1*1 99.3 98.0 6. 11-1*-1*2 Schmelzer 7.91* 1.37 100 99.0 7.91* 1.37 99.9 98.0 7<> Sweeney 7.82 1.35 101* 99.3 7.53 1.30 99.2 98.7 8o 11-2-U2 Cranston 7.1*7 1.29 10? 99.8 7.01 1.21 99.6 99.0 Average 8.10 1.1*0 102.5 99.6 7.92 1.37 99.6 99.0 WITH ECONOMIZER BAG ON CORRUGATED TUBING Automix on Automix off Ambient From Scholander Ambient Scholander 37°Sat. STPD tank Tube Mask 37°Sat. STPD Tube Mask L./Minc L./Min. 02$ 02$ 02$ L./Min. L./Min. o2$ 02$ Column: ID 11 12 13 11 "IT" 16 17“ IB NOo Date Subject 1* 10-29-12 Burrows 5.62 o9?; ioU 99.5 5.39 .93 99.0 99.0 2. 11-2-1*2 Schmelzer 5.97 1.03 100 99.5 5.97 1.03 99.8 99.1* 3. 11-3-1*2 Larson 5.21 .90 100 99.8 5.21 .90 99.8 99.5 Iu 10-30-1*2 Schmelzer 5.71* .99 101 98.3 5.68 .98 98.8 98.0 5. 11-3-1*2 Cronin 5.21 .90 100 99.9 5.21 .90 99.9 98.0 6* 11-U-U2 Schmelzer 5.33 .92 97 99-9 5.50 •95 99.9 99*7 7 . 10-30-12 Sweeney lt.69 .81 96 99.7 1*.87 •81 99.3 99.0 80 11-2-1*2 Cranston 1*.37 .75 101* 99.5 1*.21 .73 99.2 99.5 Average: 5.27 .91 100.3 99.5 5.26 .91 99.5 99.0 ABOVE DATA EXPRESSED AS PERCENTAGE WASTE OF OXYGEN Mo. Date Subject Percentage waste O2 without economizer Automix Automix On Off Col, 2-11 Col.7-16 11 i5~ Percentage waste O2 Percentage waste with automix off O2 without econ- With Without omizer bag, auto- Economizer Economizer mix off Col. 16-11 Col. 7-2 Col. 7-11 11 2 11 1. 10-29-U2 Burrows 55 1x5 39 2. 11-2-1*2 Schmelzer h9 19 At altitudes of 30,000 1x9 3. 11-3-U2 Larson h2 h 7 feet and over 100 per hi lu 10-30-1*2 Schnelzer h2 U6 cent oxygen is delivered hh 11-3-U2 Cronin 60 57 both with automix on and 51 6. 11-1*-1*2 Schmelzer h9 hh off (Aro demand regulator h9 7* 10-30-1*2 Sweeney 67 55 #1*902). 60 8* 11-2-1*2 Cranston 71 67 60 Average 5h 51 51 MAYO AERO MEDICAL UNIT MEMORANDUM REPORT to ARM AIR FORCES MATERIEL CENTER Under Contract No® w535ao»25829 The Development of a Positive Pressure Jacket for Use During Positive Pressure Breathing* SERIAL REPORTs Series A. No* 4 DATE* February lr 1S43 A* Purposeso 1* To make flying at altitudes from 43*000 foot to 48,000 feet as safe and as comfortable as at 38*000 feet or 42*000 feet* 2* To present the results of some altitude flights in the low pressure chamber in which the oxyhemoglobin saturation was studied with the use of the oximeter* 3* To present the results of a comparison between breathing in a positive pressure rebreather bag and in the positive pressure jacket. Observations wore made on the blood pressure* venous pressure, pulse rate, circulation tamo and respiratory rate in man* B, Factual Data* 1* The positive pressure jacket* a* The jacket is for use during the breathing of pure oxygen under a positive pressure of 30 to 33 mm. mercury. This will raise the altitude coiling to 48,000 feet and give a safety factor equivalent to 42,000 foot without posi- tive pressure* An altitude of 50,000 feet can bo safely reached and maintained for a short time* b. The positive pressure jacket is designed so that it can bo used below 38,000 foot as a straight constant flow system with a maximum pressure of 5 mm. mercury. In order to ascend above 38*000 feet the pressure can bo raised to 30 or 35 mm* mercury or any desired pressure by simply closing a valve. It is possible to build up this positive pressure in the jacket in a few seconds* whenever the occasion demands. o* A Bulbulian pressure mask oquippedwith a magnetic microphone is used with positive pressure jacket* d. In Appendix I ore attached specifications, description and a photograph to show the design and operation of our experimental positive pressure jacket. a 2. Oximotor observations. a. Tho oximotor records of several flights to 45,000 and 48,000 foot and one to 50,608 foot showed that the oxyhemoglobin saturation never fell below 86$. However, at 45,000 foot without positive pressure tho oximotor record on tho some subject showed 78?£ saturation and this altitude could only bo tolerated for a short time without positive pressure. In Appendix II are attached curves to show tho relation between tho oximotor reading and tho altitudo0 3, The effects of positive pressure breathing on manc a, Breathing in tho positive pressure jacket increases the pulse rate* tho blood pressure, tho venous pressure and tho circulation time* Attached in Appendix III are tables showing tho magnitude of these changos0 Co Summary. 1, Subjects have continuously breathed in the positive pressure jacket for an hour and flights between 40,000 and 50*000 foot have boon made in tho low pressure chamber. Tho subjects experienced no difficulties and with tho excep- tion of minor mask leaks, wore as comfortable at altitudes above 40*000 foot as at 38*000 foot& 2, Wo arc compiling tho results of some experimental work which will present a clearer picture concerning the methods by which the body compensates to posi- tive pressure breathing. 3, Two more positive pressure jackets are under construction aid will bo ready for use in several days. D. Acknowledgment, We wish to express our appreciation to Dr, Boothby for advice and facilities of tho Unit made available to us0 Proparod by 1st Lt« Charles B, Taylor j> M»Ce 2nd John P« Marbargcr, Ao0tt Approved by E, J. Baldos, Ph*Dft Distribution* Commanding General Attention Col« 0* 0, Benson, Jr„ Aero Medical Research Laboratory Wright Field, Dayton, Ohio Charles F» Code, M«D» Offico of tho Air Surgeon Attention Col» Loyd E* Griffis Washington, D.C« Scries A, No, 4 .3. APPENDIX I The construction and description of tho positive pressure jackets 1. Tho pressure jacket is constructed on the rebreather principle. It is a two«wallod rubberized bag with a volume of approximately 6 labors, An adjustable 1 outer foundation garment made of heavy can/as is used to give rigidity to the outer wall of the bag. The inner wall fits snugly to tho body so that when tho jacket is inflated it oxorts pressure evenly on tho chost cage and abdomen. Two crotch straps on the foundation garment keep tho jacket from creeping up the trunk® 2, Oxygon from a high or low pressure system with a regulator sot to deliver tho oxygon required at 42(,000 foot inactive enters tho jacket through a small jot, Tho mask is connected to tho pressure jacket by two pieces of large corrugated tubing® On inspiration oxygon passes from tho jacket through one of tho corrugated tubes, (A), to the mask and into tho lungs0 There is a one way valve (1) which closes with tho cessation of inspiration and onset of expiration. Gas from tho lungs is expired through corrugated tube (3’) into a shell natron container and then back into the pressure jacket through a one way valve (2) which opens only on expiration and closes at tho onset of inspiration, Tho total pressure in tho system can be regulated by a spring valve (3)„ 3, Breathing against a positive pressure as great as 37 mm* Hg-y is made relatively easy by using this sybom because on inspiration the volume of tho Jacket is decreased thus allowing for chest expansion. During expiration tho volume of the Jacket is increased- as a result of gas passing from tho lungs back into the Jacket, This makes expiration a passive motion because tho increase ing volume of tho Jacket during expiration oxorts pressure on tho chest cage. However* if tho flow of oxygon into tho Jacket is too groat* oeg, 20 liters per minute* the volume of the bag is increased so rapidly that complete inspira- tion is hampered thus destroying tho morkod case to respiration which tho pressure Jacket affords. Photograph 1 - Pressure mask • Tube to manometer • ICrogb one-way valve • Tube from Jacket to mask • Tube from mask to shell natron • Microphone outlet • Tube from shell natron to Jacket • Spring release valve Water nanometer - Oxygen enters - system Shell natron - oontai ner 4. APPENDIX II Flights in a low pressure chamber and oximeter records* 1* Flights in the low pressure chamber wore made to high altitudes in which the ability of the positive pressure jacket to hold the oxyhemoglobin saturation within safe limits was tested* The subject breathed pure oxygon for 15 minutes before the oximeter was sot in order to insure complete hemoglobin saturation* It was then arbitrarily set at 100 per cent and the flight started* The results of these flights arc shown graphically in figures 1, 2 and 3, 2. In figures 1 and 2 the c . • . linos shew the altitude and the the oximeter readings. The altitude and oximeter readings ore plotted along the ordinate and time is plotted along the abscissa* 5* Figure 1 shows the results of two flights to 45,,000 foot. These results show that in flight 1, figure 1, in which 6 minutes were spent at 40,000 foot and 2 minutes at 45,000 feet, the oximeter reading romaind around 90 per cent saturation during the former period and fell to 86 per cent satura- tion during the latter. The positive pressure breathed was between 30 and 38 cm, water. Flight 2, figure 1, shows that 10 minutes wore spent at 40,000 foot and 9 minutes at 45,000 foot and that the oximeter reading of the former period was around 93 per cent saturation and dropped to around 91 per cent during the latter. The positive pressure during this flight was hold between 34 and 44 emo water. 4, Figure 2 shows a flight to 51,440 foot made by Major Lovelace (flight l) using a positive pressure mask, and a flight made by us to 50,608 feet using the positive pressure jacket (flight 2, figure 2), The figure shows that at 49,000 foot the oximeter reading on Major Lov’olaco was between 67 and 68 per cent and at 50,000 feet it was between 62 and 63 per cent* As far as wo can determine from the records at 50,000 feet Major Lovelace was breathing against 30 cm* water. On descent at 42,000 foot the pressure was 26-33 cm, water and at 33,000 feet he was breathing against 24-34 cm. water pressure. It is interesting to note that wo remained at 49,000 foot for 8 minutes and the oximeter remained at 90 per cent end only fell to 86,5 per cent when wo reached 50,000 foot. The posi- tive pressure breathod during our flight was between 45 and 50 cm, water* Our subject was alert and comfortable at 50,608 feet. 5, Figures 3 (a) and (b) show the effect ofl the oxyhemoglobin saturation at a given altitude when the pressure in tho/jaStot is decreased and then increased. The mask pressure and oximeter readings are plotted along the ordinate and time along the abscissa. 6, Figure 3 (a) shows that at 45,000 foot the mask pressure was dropped from 43 to 15 cm, water in a period of 1 minute and that during that time the oximeter dropped from 91 to 79 per cent. The pressure was then raised to 43 cm, water and after about minute the oximeter was back to 90 per cent saturation* 7, All altitudes above 45,000 feet have boon barometrically corrected. Series A, No* 4 Key Broken lines - oximeter readings Solid lines - altitude readings i i I I I XIX 5a EFFECT OF POSITIVE PRESSURE MASK AMD JACKET ON OXYHEMOGLOBIN SATURATION Time in Minutes C, B, Taylor and J, P, Marbargcr Altitude in Thousands of Feet XIX 5b Key Broken lines - oximeter readings Solid lines - altitude readings TWO FLIGHTS OVER 50,000 FEET USING POSITIVE PRESSURE a*ASK aHD JACKET Tine in Minutes Mask Pressure Applied] C.B,Taylor and J.P.L'arbarger Febr. 1943 Oximeter Altitude in Thousands of Feet Key Broken lines - oximeter readings Solid lines - mask pres, reading! Chart XIX THE EFFECT ON THE OXYHEMOGLOBIN SATURATION AT ALTITUDE WHEN THE PRESSURE IN MASK AND JACKET IS DECREASED ADD THEE INCREASED hO ,000 feet Time in Minutes U5>,000 feet Fig. 3(a) I I C, B. Taylor and J, P, Marbarger Febr. 1. 19h3 Oximeter Mask Pressure - cm. 1^0 5 APPENDIX III 1, In general, increased intra-thoracic pressure may tend to decrease the venous return to the right heart, YiTith this in mind the following observations were made. In this series of experiments two individuals wore used, ono the asthenic type and the other the hyporasthenic typo. The results were collected on each of the individuals under the following conditions (l) under normal conditions; (2) while breathing oxygon from a robroathor bag in a metal container to which weights wore added to produce positive "rcssuro and a constant stream of oxygon flowing into the bag regulated by a spring release valve avoided the acoummulation of carbon dioxide; and (3) while breath- ing in the positive pressure jacket. The observations were made at ground level unless stated otherwise. A, Respiration rate Asthenic typo individual Normal • ••••••••o,,,«,,o,«oo<'«ooso«18 per minute Pressure rebreather bag ,,oooo»*o**oo»oe» 25 per minute (Taken after 7 min, of pressure breathing?* pressure 19-26 cm0 water,) Positive pressure jacket Oeo*o«*«*»«««»**oo*24 per minute (Taken after 7 min<,; pressure 31-37 cm, water) Hypersthenic type individual Normal • « c • ••,,, »• , , * , . • • o . » * * * » o o • 13 per minute Pressure rebreather bag , , co« ,aeo©oooo<»oeo*16 per minute (Taken after 8 min.j pressure 21-36 cm, water.) Positive pressure jacket ,, per minute (Taken after 30 min,; pressure 36-39 cm, water,) Positive pressure jacket ,,, ,.e,,ooe«« ♦•«,*« 13 per minute (Token after 60 min,; pressure 27-30 cm, water; altitude when rosp, counted 40,000 feet.) B, Pulse rate Asthenic typo individual Normal poi* minute Pressure rebreather bag • ••«,,•, ••»••<>»« «« 100 per minute (Taken after 7 min,; pressure 19-26 cm* water,) Positive pressure jacket • « • « o • t • e « o * • * # « « • • per minute (Taken after 7 min* pressure 31-37 cm, water,) Scries A* No, 4 >6> Hypersthenic typo individual Normal .«o*.©*.*o©.*©©.o©.©.©•©«•• 80 per minute Pressure rebreather bag «. • ©**©*****0*****94 per minute (Taken after 8 min*5 pressure 21-36 cm. water.) Positive pressure jacket *••©••••©•. 0©o©*©*» 06 per minute (Taken after 30 min.; pressure 36-39 cm0 water.) Positive pressure jacket ... • ©••©•©©©•©•.o ©106 per minute (Taken after 22 min*; pressure 37-39 cm. water; altitude when P.R. taken 40.000 foot.) C, Blood prossuro Asthenic typo individual Normal * .©• • © • © . © . . • 9000 ©oo #© 9 o © # *126/88 Pressure rebreather bag . 0 .©©©©©©©©©oo*. record not taken Positive pressure jacket «„ . * . .f..e©oc.... ©140/ll0 (Taken after 7 min.; pressure 31-37 cm. water.) Hypersthenic typo individual Normal .**co»o ©©ooooo.ooe©©#*©.*© 126/84 Pressure rebreather bag •*•*•* *o© ••©•••©•© 116/76, 126/92 (Taken after 7 and 13 min. respectively; pressure 25-36 cm. water.) Positive pressure jacket ..e.**©*©.©*©©*©* 126/90 (Taken after 30 rain.; pressure 36-39 cm. watorc) Positive pressure jacket ,* .**oe©e©«oooo«e 140/l08 (Taken after 28 minu; pressure 38-40 cm, water; altitude when B.P© taken 40,000 foot.) D. Venous prossuro (Direct method, antcoubital voin, lovcl r, auriclo) Asthonic typo individual Normal * c <0 9 . . ..©©o.o.o.© 000090 © • • no record token Pressure rebreather bag • ••••••••oo©oo©«o©no record taken Positive pressure jacket ..•o«..99«9©ooo©©29 cm* water (Token after 7 mine; pressure 32-37 cm* water.) Hypersthenic typo individual Normal © • » • c • 0 © 00 • 9000a ©©c4©oooo©r» water Pressure rebreather bag .©•©••©••©©•ooooa 23 cm* water (Taken after 8 min.5 pressure 21-36 cm0 water.) Positive pressure jacket **ooo..oooooooo9o «no record token Sorios A, No, 4 7- E* Circulation timo (Ether, antooubital vein (arm) to lung timo) Asthonio typo individual Normal • © • •••««•««»«•* •©•••©©•©•©©no rooord takon Pressure rebreather bag • t • © 0 9 e c » oo©oo«©©©no record takon Positive pressure jacket .«<»©o ©©©©*• ( • i » o • 10 seconds Hypersthenic typo individual Normal • ••ft».»««««»»o«©«9e©©©ae©oo 3i seconds Pressure rebreather bag eo*oo«ooooo«eoo*o»13 seconds (Token after 8 min0j pressure 21-36 cm* water*) Positive pressure jacket ©o©©©©©©©©©*©©© ©©©no record takon MAYO AERO MEDICAL UNIT MEMORANDUM REPORT to ARMY AIR FORCES MATERIEL CENTER Under Contract No, W535ac-25829 SUBJECT* The effect of positive pressure breathing on the arterial bleed pressure, venous blood pressure and the oerebro-spinal fluid pressure in the dog* SERIAL REPORT* Series A# No* 4 a DATEi February 9, 1943 A* Purposes* 1* To answer the question** is the cerebral circulation jeopardized by the increased venous pressure caused by positive pressure breathing. 2, To present the results of some studies on the dog concerning the adjustments made ty the cardiovascular and central nervous systems to positive pressure breathing. B, Factual Data# 1, Introduction, a. We have observed (Series A, 4, Feb, 1, 1943) that in man while breathing in the positive pressure jacket, there is a marked increase in the pulse rate, the arterial blood pressure, and the venous blood pressure. Since these physiological changes occur and since we have observed no symptoms,,of disounfort or cerebral disturbances (headache, loss of vision, etc.) either at ground level or at altitude after an hour or more of pressure breathing, the body must bo -able to adjust itself to the changes which occur while breathing a positive preosure. 2, Apparatus and method. a, A positive pressure jacket was designed and constructed for a dog using the same plan as that described for the human (Series A, 4, Feb, 1, 1945), b, A tracheotomy was done on an anesthetized dog and a tracheal can- cula securely inserted. This was substituted for a mask. o. Photographic records were obtained of the changes in the arterial (femoral ai’tery), venous (external jugular vein, cannula toward heart) and cerebro-spinol (cisternal puncture) pressures with the use of spoon manometers. d. The changes in the arterial, venous and cerebro-spinal fluid were studied while the animal was breathing in the jacket for different time periods and under the following positive pressures* 0, 10, 20, 30, 40, 50, 60 and 75 mm, Hg, e. In Appendix I a complete description of the apparatus and method is found. S' 3, Results* a* In the deg, as the tracheal oaygen pressure is increased to 30 mm* Hg the arterial pressure increased from 157 mm* to 181 mm. Hg, the venous pressure increased from 7 mm* to 35 mm. Hg, and the cerebro-spinal pressure increased from 16 mm. to 35 mm. Hg. Appendix II, Section (l). b. The critical level was reached when the dog was breathing against a positive pressure between 30 mm, and 40 mm, Hg, Appendix II, Section (l). c* When the tracheal pressure was raised above 40 mm, Hg the venous and spinal pressure increased directly with the increased positive tracheal pressure. The arterial pressure decreased with increased tracheal positive pressure above 40 mm, Hg, Appendix II, Section (l). d. The effect cf suddenly increasing the positive pressure against which the animal was breathing was studied by instantaneously raising the pressure from 0 mm, to 30 mm, Hg and from 0 mm, to 75 mm. Hg, Appendix II, Section (ll). e. About 80 seconds are required for the complete adjustment of the arterial, venous and cerebro-spinal pressures to changes in the positive pressure against which the animal is breathing. This depends somewhat upon the magnitude of the change. Appendix II, Section (ll). (l) Fifteen seconds after the pressure was raised from 0 mm, to 30 mm, Hg the systolic blood pressure decreased momentarily from 200 mm, to 190 mm, Hg and the diastolic increased from 130 mm, to 140 mm, Hg, After 50 seconds the average systolic pressure was 210 mm, and the average diastolic pressure was 160 mm, Hg, Ten minutes later there was no change. Appendix II, Section (ll). (2) There is always a greater increase in diastolic rather than systolic pressure. This was also observed in man. (3) See Appendix II, Section (II) for complete details. f. The arterial, venous and cerebro-spinal pressures are so sensitive that changes in them can be observed during the respiratory phases 'while the animal is breathing in the jacket against 30 mm, Hg positive pressure. See Appendix II, .Section (III), g. When the pressure against which the animal is breathing is reduced from 30 to 0 mm, Hg, about 20 seconds ore required for tho arterial, venous and cerebro-spinal pressure to return to normal. (I) Four seconds are required for venous and cerebro-spinal pressures to return to normal and 18 seconds are required for the arterial pressure to return to normal* h* See Appendix XI, Section (IV). i« Appendix III contains a discussion of the cardiovascular changes which occur during positive pressure breathing. See Appendix III and Exhibit 9, Series A, No, 4 a .a j* Aftor tho oxporimontal work was complete, tho dog still appeared to be in good condition* k© Tho case of breathing in tho jacket is well illustrated in this experiment in that tho respiratory rate of the anesthetized animal (respira- tion under those conditions entirely involuntary) was normalo C* Conclusions* 1* The oxporimontal work presented in this paper suggests that positive pressure breathing in tho jacket against pressures as groat as 30 to 40 mm© Hg produces no harmful effects on tho cerebral circulation. 2* Tho increase in intra-cranial pressure accompanying positive pressure breathing probably insures adequate venous return from the brain by offsetting tho increase in venous pressure* 3* From experimental data already reported and found in this report,* and from cardiac output and retinal vessel studios to bo reported shortly, it is very probable that tho cardiovascular system responds favorably to positive pressure breathing in tho jacket© Prepared by 2nd Lt« John P„ Marborgor, A^C0 1st Lt0 Charles B« Taylor 3 McC» Approved by Bf J, Baldos., PhsD0 Charlos F, CodQj M0D» Distribution* Commanding General Attention Col* 0* 0. Benson, Jr* Aero Medical Research Laboratory Wright Field, Dayton, Ohio Office of the Air Surgeon Attention Col* Loyd E* Griffis Washington, D*C# Series A, No© 4 a APPENDIX I 1. Tho dog (27*5 lbs*) usod in this experiment was anesthetized by an intra-peritoneal injection of 5% pentobarbital («,3 cc* per lb*)* A tracheotomy was performed and a tracheal cannula securely fastenedo This cannula which replaced a mask was connected to tho pressure jacket by tho same tube connec- tions used in tho human jacket including a soda lime absorber can* Tho pressure against which tho animal breathed was measured by a manometer connected to tho cannula* 2* Tho dog was placed on its back and lashed to a Its head was turned to one side and the head end raised through 21° from tho horizontal 30 Tho arterial blood pressure was measured by connecting a spoon manometer to a cannula inserted (toward heart) into tho femoral artery* tho venous pressure by connecting a spoon to a cannula inserted (toward heart) into tho external jugular vein; tho corobro-spinal fluid pressure by a spinal noodle inserted into tho cistorna magna. The arterial and venous cannulao were flushed with 3% sodium citrate solution and tho corobro-spinal cannula by saline solution* Tho spoon manometers in this experiment wore all care- fully calibrated* APPENDIX II 1* Tho following experimental procedure was usod* After the spoon manometers and tho cannulao wore carefully adjusted tho camera was started and a record was taken while tho dog was breathing under normal conditions* i„o,, without positive pressure* In this way tho normal base lino for each manometer was established and any change which occurred while tho animal was breathing positive pressure could bo carefully calculated^ 2* Section (I)* a* Tho animal breathed under different positive pressures and the changes wore measured as follows* tho pressure in tho tracheal cannula was raised to 10 mm* Hg* After 3 minutes it was assumed that tho animal was adapted to breathing against this pressure and a record of tho changes from tho normal was made* Tho pressure in tho tracheal cannula was then raised to 20 mmt Hg and another record was taken after 5 minutes* This procedure was repeated after tho tracheal cannula pressure had boon raised to 30, 40, 60, 60 and 75 mmP Hg, except that tho dog breathed under those pressures for tho following time periods: 5, 10, 15, 15, 1 and 5 minutes respectively, before tho records wore made© b0 The results of this experiment are presented in tabular form in Exhibit 2, It can be seen that in tho dog, as tho tracheal oxygen pressure was increased to 30 mm* Hg, there was a marked increase in arterial, venous and corobro-spinal pressure, and that tho critical lorvol was reached when tho dog was breathing against a positive pressure of between 30 and 40 mnir Hg, It con bo soon that after tho tracheal pressure was raised above 40 mm* Hg tho venous and spinal pressure increased progressively with tho increased pressure, and that tho blood pressure decreased with an increase in tracheal pressure above 40 mm* Hg, Series A, No, 4 a 5 EXHIBIT 2 Traohoal Rosp, Vonous Planimotor Systolic Diastolio 0*> Prossuro Spinal P por Prossuro Pulso Average Prossuro Prossuro (mm, Hg) Time (mm. Eg) min. (mm© Hgi Rato B© P0 Artorial 0 0 min® * • f 16 24 7 200 157 175 135 10 3 min0 20 12 7a5 200 163(j5 185 150 20 5 min. 27 8,5 24 192 168,5 192.5 160 SO 5 min. 35 10 35 192 18X.0 195 165 30 10 min© 27 7,5 35 172 159,8 197 143 40 15 min© 38 6 45 170 172e5 204 156 50 15 min. 49 60 160 172.5 199 158 60 1 min. 57 82 170 170o5 195 160 75 5 min. 63 140 152 175 145 ►ft 3* Soction (II)* a. Section (I) shows that tho venous and corobro-spinal pressures varied with the positive pressure, Tho venous and spinal pressures varied directly with tho increased positive pressure, Tho arterial pressure also varied directly with increased positive pressure but reached an optimum point between 30 and 40 mm, Hg and then varied inversely with a farther increase in pressure. b* It was observed while obtaining the record in tho preceding part that tho corebro-spinal pressure was extremely sensitive to changes produced by positive pressure breathing. This point was tested as follows* tho trachol oxygon pressure was instantaneously raised from 0 mm* to 30 mm* Hg and from 0 mm* to 75 nm, Hg* o# Tho results of raising tho pressure from 0 to 30 mm. Hg are showsn in Exhibit 5* It can be seen that 15 seconds after tho pressure was applied tho systolic blood pressure decreased momentarily from 200 to 190., and the diastolic increased from 130 to 140 mm. Hg* After 50 seconds tho average systolic pressure was 210 mm* Hg end the diastolic was 160 mm* Hg* Ton minutes later there was no change in arterial, venous or spinal pressures* It is interesting to note that tho pulse pressure in tho dog decreased from 70 to 50 mm. Hg while breathing at 30 mm* Hg. Wo have observed a similar decrease in man (Series A, 4, Fob. 1, 1943) decreasing from 40 to 30 mme Hg« This is duo to a greater increase in diastolic rather than systolic pressure* Exhibit 5 also shows tho rapid response of tho spinal pressure after 30 mm0 Hg is applied, increasing after 15 seconds to 25 mm. and remaining practically constant thereafter. Tho spinal and venous oonnulao had to be readjusted be- fore this procedure and now base linos hod to bo established. When this record was taken tho venous cannula did not function. Proper rdadjustmdnts wore made and when tho positive pressure was raised from 0 to 75 mm. a record of tho change in venous pressure was then obtained. Exhibit 6 shows the changes which occur when the pressure is instantaneously increased from 0 to 75 mm. Hg. This curve shows that a 5 second latent period existed after the positive pressure was raised from 0 to 75 mm. before tho spinal pressure changed. Then it rapidly increased and after 45 seconds had changed from 7 mm, to 68 mm, Hg. Tho venous pressure did not respond to increased positive pressure until 25 seconds after tho pressure was applied. Sixty seconds later it increased from '5 to 68 mm, Hg, The changes which occurf in arterial, venous an d spinal pressures in dog after 02 _ pressures was instantaneously- increased from 0 mm. to 30 mm Hg. ;#id pressures after 10 _ min. plus pressure breath- ing. Note effect of respir- ation on pressures. - Feb. 19U3 Chart XIX 6a Inspiration Venous. Pressure Spinal pressure Time in Seconds 10 min* After 10 rain, breathing against 30 mm. Hg positive pressure Exhibit 5 TIME IN SECONDS C, B, Taylor and J. P. Marbarger Millijaeterfi of Mercury- i iii ii The changes which occur in venous and spinal pressures in the dog after the oxygen pressure was instantan- eously increased from 0 mm* to 75 nun. Hg Chart XIX-6b Febr. Iyh3 EXHIBIT 6 TIME IN SECONDS C.B.Taylor and J.P. loaroarger Millimeters of Hg. Pressure Millimeters of Mercury 7- 4. Section (III). a* In Section (l) and (II) we have demonstrated the rapid response of the arterial, venous and oerebro-spinal fluid pressures to positive pressure breathing. It was found that these pressures are so sensitive that changes in them could even bo observed during the respiratory phases while breathing under positive pressure. These changes wore recorded after the dog had been breathing for 10 minutes against a positive pressure of 30 mm. Hg. (Tracing not available.) b* These observations raise the questions ore the changes in arterial pressure during inspiration and expiration a direct function of the changes in spinal pressure, or is the increased arterial pressure during expiration due to the more complete filling of the heart during the preceding inspiration and the decrease in arterial pressure during inspiration duo to the incomplete filling of the heart during the preceding expiration? 5. Section (IV). a. In order to complete the series of changes in arterial*, venous and spinal fluid pressures which occur while breathing under a positive pressure, this section pertains to the adjustments in the arterial, venous and spinal pressures immediately after the pressure against which the cn imal is breathing is reduced to 0. b« Exhibit 8 shows these changes after the positive pressure was reduced from 30 to 0 iim. Hg« Four seconds after the positive pressure was moved the venous and spinal pressures wore back to normal# Eighteen seconds wore required for the arterial pressure to return to normal* There was a rapid decrease in arterial pressure 1 second after the pressure was reduced, followed by a gradual increase in arterial pressure above normal during the next 4 seconds, followed by a subnormal decrease requiring 7 seconds, and then a gradual increase to normal arterial pressure# These changes in arterial pressure are due to the rapid filling of the heart after the positive pressure against which the animal was breathing was removed« Series A, No, 4 a 5he changes which occur in the systolic, diastolic venous and spinal pressures in the dog when the — pressure breathed by the animal is instantaneously decreased from 30 ran, to 0 mm. Hg* Animal breathed against 30 mm. Hg, £ minutes before pressure — was decreased, j 1 1 1 r 1 1 Ohart XIX-6c Feb. 19U3 TIME IN SECONDS EXHIBIT 8 E 1 1 C.B.Taylor and J.P.icarbarger Millimeters Mercury Pressure APPENDIX III (DISCUSSION) 1, Wg foel that one can assume that while breathing positive pressure in a pressure jacket the chest and abdomen are under an increased barometric pressure and that the central nervous system responds as if it wore subjected to positive pressure or an increased barometric pressure by virtue of the cran- ium being a fixed cage and most of the spinal column being subjected to the increased barometric pressure* 2* It has boon demonstrated that the venous pressure does rise with positive pressure breathing. This was also observed in man and one might wondor about the adequacy of the cerebral circulation, Tho observations made on the dog demonstrate why the cerebral circulation is not jeopardized during positive pressure breathing* 3* We have observed on increase of 25 to 30 mm* Hg.ift thb arterial blood pressure in man and 20 mm. Hg increase in the venous pressure while breathing against 30 mm. Hg pressure in tho jacket. Since wo have observed no evidence of impaired cerebral circulation after on hour of positive pressure breathing (30 mm. Hg) in tho jaOkot, wo feel that the intra-cranial pressure in man must increase just as it does in the dog. For the purposes of demonstration, the pressures observed in the dog while breathing 30 mm* Hg positive pressure have been transferred to tho human* 4, Tho flow of blood through the vascular system depends upon a pressure gradient. Let us compare tho pressure gradients which ore responsible for cerebral circulation under normal conditions and after breathing against 30 mm. Kg positive pressure for 5 minutes. Under normal conditions tho average arterial pressure was 157 mm, Hg and this pressure had to exert itself against 16 ramc Hg intra-cranial pressure which was acting on tho collapsible vessels of tho brain. This made tho effective cerebral arterial pressure 141 mm, Hg, While breathing against 30 mm, Hg positive pressure the average arterial pressure was 181 mm* Hg, In this case the spinal pressure was 35 mm, Hg and the effective cerebral arterial pressure was 146 ran, Hg. Tho effectivo arterial blood pressure to tho brain remains practically tho same in both cases. 5, Under normal conditions tho venous pressure is 7 mm, Hg* Tho forces tending to counteract venous pressure are the intra-cranial pressure and the hydrostatic pressure of tho column of blood from the base of tho brain to the heart* Under normal conditions tho intra-cranial pressure was 16 mm, Hg and the hydrostatic pressure in man which remains constant is about 18 ram* Hg, The effective pressure to insure venous return under normal conditions will be tho sum of tho intra-cranial pressure plus the hydrostatic pressure minus tho venous pressure. This is 16 plus 18 minus 7, or 27 mm, Hg, Therefore, the effective pressure for venous return is 27 mm, Hg, After 5 minutes of positive pressure breathing the intra-cranial pressure was 35 mm* Hg, tho hydrostatic pressure remains tho same (18 mm. Hg) and the venous pressure was 28 mm, Hg, In other words, the effective pressure for venous return was 35 plus 18 minus 28, or 25 ran. Hg, It can bo seen that this is practically the same as under the normal conditions. 6, It was pointed out earlier that there is an increase in the arterial and venous pressure in man and yet there is no discomfort after breathing in the suit for an hour or more. Since this is tho case, wo feel that tho cerebro- spinal pressure changes observed in tho dog must also occur in man and by virtue of this fact man is able to tolerate positive pressure breathing. MAYO AERO MEDICAL UNIT MEMORANDUM REPORT to ARMY AIR FORCES MATERIEL CENTER Under Contract Noa W535ao~26829 SUBJECT* The effect of positive pressure breathing on the appearance of the retinal vessels and on the intraocular pressure in man0 SERIAL REPORT* Series A, No* 4 b DATE* February 17, 1943 A* Purposes* 1* To study the changes, if any, in the diameter of the retinal vessels in man while breathing under positive pressure* 2* To study the changes, if any, in the intraocular pressure in man while breathing under positive pressure* 3* To investigate the possibility of the formation of papilloedema in man as the result of increased venous and intracranial pressure due to positive pressure breathing* B* Factual Data* 1* Experiment* Observations on the change in the diameter of the inferior temporal artery and vein were made while the subject was breathing under the following conditions: (l) breathing room air under normal conditions, (2) breathing 100 per cent oxygen without positive pressure, (3) breathing 100 per cent oxygen in a pressure rebreather bag against a positive pressure of 20-36 mm* Hg, (4) breathing 100 per cent oxygen in the pressure jacket against a posi- tive pressure of 30-33 mm* Hg* Exhibit 1 shows the procedure and the results obtained* a* Direct vascular measurements were made with idle use of an ophthal- moscope to which was attached a specially designed metric measuring device* The vessels were continuously observed and records of the changes were period- ically made* In addition to these observations, photographic records of the changes were taken* See Exhibit 1 and 2, (l) The results show that the diameter of the inferior temporal vein was *161 mm* while breathing room air under normal conditions, and that after 5 min* breathing oxygen without positive pressure the vein was *131 mm* in dioimbter* Ten minutes later the diameter was *136 ram* The limit of error of the vascular measurements was ©008 mm* The reduction in size when oxygen was administered is significant* There is no significant difference between the two readings recorded while breathing oxygen without positive pressure* There was no further change in size even while breathing oxygen under a posi- tive pressure* In other words, after the initial reduction in size when oxygen was first administered without positive pressure, the size of the veine- remained constant* (2) The results (Exhibit l) show that there was a slight reduction in the diameter of the artery after oxygen without positive pressure was admin- istered and that no change occurred after the subject breathed against positive pressure» (3) Therefore, when the subject breathed oxygen without positive pressure after breathing room sir there was a reduction in the diameter cf the inferior temporal artery and vein. After this initial reduction there was no further reduction even after positive pressure breathing was administered. (4) A few minutes after breathing in the positive pressure jacket, the veins of the fundus appeared bright red. They approached the color of arteries. b0 Observations were mode on the intraocular tension under the same conditions found in paragraph (a) above. A tonometer was used to make those observations. The results ore presented in Exhibit 1. (1) Tho results show that thoro w%s very little change in the intraocular tension while breathing under positive pressure. The slight changes noted ore within tho limits of error of tho toohnio used* o. Thirty-five minutes after breathing in the positive pressure jacket against a pressure of 30-33 mm* Hg there was no evidence of papillitis or early papilloedema. d. Observations were made on the time required for the vessels to regain their normal size after 35 minutes of positive pressure breathing against 30 to 33 mm. Hg oxygen pressure in the pressure jacket. The results are pre- sented in Exhibit 1. (l) Exhibit 1 shows that 11 minutes after the oxygon was removed the vein and artery had returned to normal. e. The above results indicate that the changes which occurred were the result of oxygon rather than of positive pressure. These changes which accompany oxygen breathing were more carefully studied on throe subjects and the results obtained are presented in Bxhibitis 3, 4 and 5, The diameters of the vessels are plotted along the ordinate and time in minutes along the abscissa. Measurements of the changes wore taken frequently after the subject started to breathe oxygen without pressurec and the time required for vascular readjustment was recorded. Then oxygon was removed and the recovery period was recorded. (l) Exhibit 3 shows that for subject 1, 6 minutes wore required for arterial adjustment and 12 minutes wore required for venous adjustment. Throe and one-half minutes after oxygon was removed the vessels wore back to normal. (2) Exhibit 4 shows that for subject 2, 12 minutes were required for the vessels to reach minimal size. After oxygon was removed, about 4 minutes were required for the vessels to return to normal. (3) Exhibit 5 shows that about 3 minutes wore reqiirod for the vessels in subject 3 to reach minimal size. Two and one-half minutes were required for these vessels to return to normal© In each case the time ro- rquirod for recovery was considerably less than the time required for the vessels to roach minimal size* It is interesting to not© that there was a difference of 10 years between the ago of subject 3 and subjects 1 and 2e 2* Discussion* a* For a discussion of intra-ocular pressure and the diameter of tho retinal vessels consult Appendix 1* b* For a discussion of, and a consideration of pa£illoedema in positive pressure breathing, see Appendix II* C* Conclusions* 1* There is a slight reduction in the size of tho retinal vessels when pure oxygen without positive pressure is breathed* 2, Breathing oxygon in a pressure rebreather bag or in tho positive pressure jacket does not increase tho diameter of the retinal veins© 3* There is no appreciable change in tho intra-ocular tension when breathing against a positive pressure as high as 33 mm* Hg* 4,, From tho observations mentioned in (b) and (c) above and from tho literature reviewed in Appendix I, it can probably bo concluded that ophthalmic and cerebral circulation are not jeopardized by positive pressure breathing- 5© The formation of papilloedema was not observed after breathing against a positive pressure of 30 to 33 mm* Hg for 35 minutes* Prepared by 1st Lt* Charles B* Taylor.» M*C* 2nd Lt* John P* Morbargor, A*Ag.F» Approved by J, Baldosj Ph»D« Charles F* Code. M*D» Distributions Commanding General Attention Col* 0* 0« Benson, Jr* Aero Medical Research Laboratory Wright Field, Dayton, Ohio Office of the Air Surgeon Attention Col* Loyd B. Griffis Washington, D.C* Series A, No* 4 b APPEKDIX I 1, It is a well known fact that in right heart failure or any condition whore venous stasis is marked* the retinal veins become markedly engorged (l)« Having observed an increased venous pressure in man during positive pressure breathing* wo felt that a study of the appearance of the retinal vessels during positive pressure breathing might bo a good index of the degree of venous stasis in the eye and possibly in the brain* 2. It can bo soon from tho data presentod above that there was no chango in tho diameter of the retinal veins or arteries after 35 minutes of positi*?© pressure breathing in the positive pressure jacket. This evidence indicates very strongly that the circulation of tho ey and of the brain remains (i«e, there may be pressure changes but arterial and venous flow remain constant) dvrijg positive pressure breathing of 30 to 33 mm. Hg in tho jacket for periods as long as 35 minutes. 3, The fact that the intra-ocular pressure remained essentially constant during positive pressure breathing is also good evidence that the arterial and venous flow of the eye and the brain are the same as normal during positive pressure breathing. According to Duke-Elder changes in arterial pressure are reflected directly in the intra-ocular pressure when the capillary circulation remains passive but this is controlled in part by the capillary-motor nervous mechanism, Duke-Elder and Adler (3) also state that if the venous pressure is altered, other things being equal* the intra-ocular pressure varies very intimately with it. They point out various methods used in producing venous stasis such as tying the vortex veins as they issue from the eye (causing a rise in intra-ocular pressure to 80-90 mm, Hg), A similar rise in intra-ocular pressure occurs on ligating the veins at the back of the orbit or obstructing venous return by rctro-bult** injections or retro-bulbar haematomata, or in exophthalmic conditions. These conditions are out and out venous stasis condi- tions and are very similar to other experiments mentioned by Duke-Elder whore all the channels of venous return are simultaneously impeded* such as passing a ligature around the neck compressing the thorax* or abdomen, or obstructing the superior vena cava. Hero one also has a marked increase in intra-ocular pressure. 4, It was pointed out in Serial Report (Series A* No, 4 a) that the intro-* cranial pressure rises as the venous pressure rises. This probably insures adequate cerebral venous return. It is true that most of the arterial venous supply of the eye comes through the cranium and if the cerebral venous return is impaired as in right heart failure or obstruction of the superior vena cava* etc, as nottioried above* there would bo an increase in the size of the retinal veins and an increase in intra-ocular pressure. Neither an increase in the diameter of the retinal veins nor an increase in intra-ocular pressure occurred during positive pressure breathing. This indicates (l) that the circulation of the eye* both arterial and venous, maintained normal proportions and was not impaired and (2) that probably the cerebral blood flow (both arterial and venous) v/as not impaired. (1) Cameron* 1933* Vol, 17, pp0 167* Brit, J,0, (2) Duke-Elder, Text Book of Ophthalmology, 1933, Vol, 1, pp„502-505,C,V,Mosby Cofl (3} Adler* F, H,,"Clinical Physiology of the Stye" McMillan Co,,N,Y/>1933*p,369, Series A- No, 4 b 5 APPENDIX II 1, Another question which arises and deserves further investigation is the probability of the formation of papilloodoma duo to the increased intra-cranial pressure associated with positive pressure breathing, Duke- El dor (3) stated ”lt has been demonstrated and it is an obvious logical proposition, that in general terras there is a fairly close relationship between the venous pressure at the disc and the intra-cranial pressure} the former keeps from 2 to 4 mm* Hg above the latter in order to allow the circulation to bo maintained, rising v/ith it st6p by stop until the corobro-spinal pressure, roaches the intra-ocular arterial pressure at which point the circulation ceases. It was found by (Sobanski A# F. 0* 137, 84, 1937) that if the normal relationship between the pressure in the central vein and artery (usually la3) was seriously disturbed so that the two approximated, then papilloodoma was prone to develop; if the arterial pressure rose with the intra-cranial pressure (that is, v/ith the venous pressure), no oedema followed, but if it did not and the relation between the venous nnd arterial pressure approximated 1*1*5 papilloodoma invariably resulted*” 2* Wo found that in the dog breathing against positive pressure (Series A„ No* 4 a) the arterial pressure roso with the intra-cranial pressure up to 30 Hg of positive pressure breathing, at which time the intra-cranial pressure was 35 mm* Hg, and that as the intra-cranial pressure was increased above that point by greater positive pressure breathing, the arterial pressure decreased,* In our experiment the intra-cranial pressure increase was the result of increased venous pressure and increased intra-thoracic and intra-abdominal pressure* 3* In the dog it appears that in positive pressure broaih ing in the jacket up to 30 mm* Hg positive pressure, the arterial pressure responds to increased intra-cranial and venous pressure by increasing proportionately, thus maintaining the normal relationship between the pressure in the central retinal vein and artery (usually 1*3); but as the amount of positive pressure breathed against is increased above 30 mm, Hg the arterial pressure begins to decrease, thus upsetting the 1*3 central retinal vein and artery ratio* As Duke-Elder stated above, as the ratio approached 1«1,5 papilloodoma invari- ably results; therefore papillooderaa may possibly develop if the amount of positive pressure in the pressure jacket is greater than 30 mm, Hg, 4* In man after 35 minutes of positive pressure breathing in the jacket against 30 - 33 mm* Hg there was no evidence of early papilloedoma. Wo realize that this is not a long enough time interval and that if greater pressures had been used, wo might have noted pa£llloodema. It seems that further investiga- tion of this problem should be carried out such as l) breathing against positive pressures greater than 30 mm, Hg for fairly long periods of time and observing the optic disc for papilloodoma, and 2) measuring the retinal arterial and venous pressure v/ith an ophthalmic dynamometer® (1) Duke-Elder, ibid Vol* III, pp, 2959-2960, Series A, No* 4 b. EXHIBIT 1 Subject* C, B, Taylor, The change in the venous, arterial ratio In the retinal vessels of the right eye (size) and the ohange in the intra-ocular tension (left eye) under the following conditions: normal (control), oxygen without pressure, oxygen with positive pressure rebreather bag and oxygon in positive pressure jacket. Conditions Inferior vein Time after exp* conditions established |Inferior temporal artery Time after exp® conditions established Pressure breathed against Intra-ocular tension Tonometer Photo- graphs Time Remarks l.Control-breath- ing room air under normal conditions Diameter Diameter 15 mm* Hg 3 nor- mals taken Optic disc including temp, oral orescent was 2*2 mm© 0I6I mm* *106 mm* 2©0xygen without positive pressure *131 mm® *136 mm* after 5 min® after 15 min* o102 mm® *097 ram* after 6 min* after 17 min* 15 mm. Hg after 19 min* 2 pht* after 20 min, 21 min. pres- sure rebreather bag® *131 mm* *142 mm® after 4 min0 after 10 min* *110 mm* *106 mm* after 5 min* after 11 min* 26 - S3 20-35 mm* Hg 13 mm* Hg after 15 min* H P M b. e 4 5 y o p . . 4*Positive pres- sure {Jacket ®144 mm® ©136 ram® c136 mme *136 mm0 after 2 min* after 7 min* after 16 min® after 24 min* *102 mm* *102 mm* o102 mm* *102 mm* after 3 min* after 8 min* after 17 min* after 25 min* 30 - 33 17 mm* Hg after 35 min* 4 pht* after 9 min* 11 min. 30 mirk 32min* (Ko da- chrome) After 25 min© fundus bright red(all ves- sels)* Veins smaller than normal but net changed since 0g originally administered* Veins approach color of arteries i.Oxygen and pressure removed* *165 mm* after 10 min* *106 mm* after 11 min* Time Ten- after sion P*P* remv* mm* 2 min. 15 4 min* 13 6 min* 13 8 min* 13 10 min * after 0g and pres- sure remeved* Fundus in gen- eral is deeper red* The veins are darker red* 4 Limit of,error Sea?S?8Mi8Es is ©C08 mm* 1. Control; breathing room air under normal conditions. 2, After 20 min. of breath ing oxygen without positive pressure. 3. After 7 min, of breathing against 25-35 mm. Hg. oxygen in the positive pressure rebreather bag. 4. After 12 min. of breathing against 25—35 mm. Hg. oxygen in the positive pressure rebreather bag. 5. After 9 min. of breath- ing against 30-33 mm. Hg. oxygen in the positive pressure Jacket. 6. After 11 min, of breathing against 30—33 mm. Hg. oxygen in the positive pressure Jacket. 7. After 30 min. of breathing against 30—33 mm. Hg. oxygen in the positive pressure jacket. 8. Control; breathing room air under normal condi- tions . 9. After 20 min, of breathing against 30 mm. Bg. (20 per cent oxygen, 80 per cent helium mixture) in positive pressure jacket. Exhibit 2. Feb. 19U3 Chart XIX 7a EXHIBIT 3 Six ninnies required for arterial adjustment and 12 minutes required for -venous adjustment. One arid one-half minutes after O2 removed the vessels wer e back to nor... 1. Chygen discontinued Vein Artery Subject ffl - Age 23 C, B. Taylor and J. P. Marbarger O2 Applied Normal (no O2) Chart XIX ?b THE RETINAL VESSELS REACHED MINIMAL SIZE IN 12 MINUTES AND ABOUT I MINUTES WERE REQUIRED FOR THE RETINAL VESSELS TO RETURN TO NORMAL AFTER THE REMOVAL OF OXYGEN Time in Minutes Exhibit U O2 Discontinued | Artery Vein Subject #2 - Age 27 100/S Og Applied Diameter of vessels in nmu Chart XIX 7c THREE MINUTES WERE REQUIRED FOR THIS SUBJECT'S RETINAL VESSELS TO REACH MINIMAL SIZE. TWO AND ONE-HALF MINUTES WERE REQUIRED FOR THE VESSELS TO RETURN TO NORMAL. EXHIBIT 5 Time in Minutes Vein Artery Subject #3 - Age 18 Diameter of Vessels in mm* MAYO AERO MEDICAL UNIT MEMORANDUM REPORT to ARMY AIR FORCES MATERIEL CENTER Under Contract No, ac-25?829 SUBJECT: Further studies on the effect of positive pressure breathing on the appearance of the retinal vessels in man, A supplement to Serial Report, Series A, No, h b„ (All the ophthalmoscopic observations reported in this report and in Serial. Report Series A, No© h b were made by Doctor C. W, Rucker of the Section on Ophthalmology, Mayo Clinic,) SERIAL REPORT: Series A, No, 1* b-2. DATE: April 23, 19U3 A, Purpose. To study the changes in the diameter of the retinal vessels and venous pressure of the retinal veins in men while breathing twenty per cent oxygen and eighty per cent helium under positive pressure in the positive pressure jacket. B, Factual Data., 1, Experiment, Observations on the change in the diameter of the inferior temporal artery and vein and on the venous pressure of the retinal vein were made while the subject was breathing under the following conditions; (l) breathing room air under normal conditions, (2) breathing twenty per cent oxygen and eighty per cent helium under 30 mm, Hg positive pressure in the positive pressure jacket. a. Indirect vascular measurements were made with the use of an ophthalmoscope to which was attached a specially designed metric measuring device. The vessels were continuously observed and records of the changes were periodically made. Retinal venous pressures were measured before and during positive pressure breathing by the indirect tonoraetric methqjl (exhibit unavailable). In addition to these observa- tions photographic records were taken. Picture number 8 and 9 Exhibit 2, in Serial Report: Series A, No, k b, nThe Effect of Positive Pressure Breathing on the Retinal Vessels on the Intraocular Pressure in Man,11 dated February 17, 19a3e 2, Results. The results show that the diameters of both the retinal artery and vein remained the same as normal during positive pressure breathing in the positive pressure jacket (pressure 30 ram, Hg) while breathing twenty per cent oxygen and eighty per cent helium. a. It was found that during positive pressure breathing the subject’s venous pulse which was normally present disappeared but could be re-induced by increasing the intra-ocular pressure about £ mm, Hg. This observation indicates that the retinal venous pressure increased 5 mm, Hg during positive pressure breathing of 30 ram, Hg in the positive pressure jacket. C. Conclusions« lo During positive pressure breathing tf 30 mm* Hg in the positive pressure jacket using a mixture of twenty per cent oxygen and eighty per cent helium there are no changes in the diameter of the retinal veins* 2a Under the same conditions as mentioned in (l) above there is about a £ mm. of Hg increase in retinal venous pressure. Prepared by C„ B. Taylor, 1st Lt. M> C.-> J» P» Marbarger, 2nd Lt, AAF MAYO AERO MEDICAL UNIT MEMORANDUM REPORT to ARM? AIR FORCES MATERIEL CENTER Uhdor Contract Noc W535ac-25829 SUBJECT* The effect of breathing against 3035 mm, Hg on the cardiac output® SERLAL REPORT* Series A, No® 4 c« DATE* February 24, 1943 A® Purpose® To observe the effect of positive pressure breathing in the pressure Jacket on the cardiac output in man by means of the roentgen kymograph® B* Factual Data® This weekly report and Serial Report Series A, No® 4 a (on the dog) were detailed investigations on but one subject and one animal® We regret that this is the case, but the experimental work reported was very carefully carried out® Both of these experiments wore carried out by us and at our own personal ex- pense; lack of subjects, time, money and permission made it impossible for us to further investigate these problems® We feel that the results presented are pertinent to the problem of positive pressure breathing and should stimulate further investigation® 1® Introduction and method® Observations on the cardiac output and changes in heart volume during positive pressure breathing were made on one individual on three separate days with the use of the roentgen kymograph® Two of the determinations were made with the subject in the sitting position acid the other in oho erect position® With each of the determinations the roentgen kymogram was token before the onset of positive pressure breathing against 30 - 35 mm® Hg in the jacket, and at varying time intervals during positive pressure breathing® The diastolic and systolic heart volume, the stroke output and the minute output were calcu- lated from the roentgen kymogram and changes in those wore compared in a relative way® In studies of this nature the direction and magni- tude of changes in heart functions with positive pressure breathing can bo accurately ascertained by comparing them in a relative way with values obtained immediately before positive pressure breathing® Therefore, it is not essential to question as to whether the values obtained represent the absolute values for the heart functions in this individual® Neither is it necessary to make the determinations under basal conditions® This subject was selected for these observations because he has been exposed to altitudes as high as 60,000 feet and to altitudes from 45,000 to 48,000 feet for as long as 40 minutes at a time in the positive pressure jacket® He has also been able to move around in the chamber with ease and do femoral arterial punctures at 46,000 feet. The other subject who has also had con- siderable experience in the positive pressure jacket was not satisfactory be- cause dense hilar markings obliterated the details of the cardiac silhouette® a# Tho following method was used. The diastolic outline of the cordiao contour was drawn on the x-ray film selecting a reference diastolic "peak" in one of the exposed strips# Tho remaining diastolic peaks occurring at tho same moment of time in the other exposed strips were then joined to complete tho lateral contours of tho hoort0 The same procedure was used to determine the systolic outline, the systolic reference always being tho systolic “valley” immediately following tho reference diastolic peak in each of the exposed strips# The systolic and diastolic outlines wore joined asymptotically to the point of fusion in tho uncertain regions of tho base and apex of tho heart* In any series of tracings tho vertical height of the heart was kept constant because tho horizontal grid of the kymograph does not reflect changes in tho cardiac contours in this sagittal direction® b« Tho systolic and diastolic area of tho heart was then determined by planimetry and corrected for distortion by the equation* A =t A1 (Y - C) Y2 whore A rs true area, A* observed area, Y =s distance x-ray tube to tho film which was 36” in our determinations, and C r: distance from tho outer margin of the hoaftto tho film which is approximately one-third the anterior-posterior diameter of the chest, plus 4 cm# which represents the average distance from chest wall to tho film v/hen tho suit is on# o# Tho volume of the heart and stroke output of tho left ventricle were determined from tho formula of Keys and Friodoll (l) in v/hich 1 45 Volume =3 0o64 x area ° and Stroke output =e diastolic - systolic volume# d# Since the systolic and diastolic outlines of the heart are joined in tho sagittal direction, the difference between tho diastolic volume and the modified systolic volume is approximately half as great as the actual total change between those volumes so that their difference gives the output of one ventricle rather than two. Keys and Friedoll (1) have found a close correlation between tho stroke output as determined by tho roentgen kymogram and tho Groil- man acetylene method of determining stroke output when normal subjects are used# e« The pulse rates were calculated from the x-ray film by counting tho number of contractions occurring in a unit time# Tho time v/as recorded by the oscillations of an electric timer superimposed on tho x-ray film# The minute output was then determined by multiplying tho stroke output by tho pulse rate# f# Exhibit 2 shows a table of the results obtained. 2# Results# a* Exhibit 2 shows that the results obtained on the throe determina- tions while breathing against 30 - 35 mm. Hg in the positive pressure jacket were all uniform in that they showed a marked decrease from the normal in the diastolic and systolic heart volume and the stroke output. However, the decrease in the stroke output was compensated for by a marked increase in the subjects pulse rate so that the minute output vdiilo breathing against positive pressure was essentially the same as under normal conditions*i0Oo,without positive pressure (l)Keys* A»,Friodell,H<,L5>,Garland:>L«HoJ>Madrazo,M.Fo and 1940, The American Journal of Roentgenology and Radium Therapy, Vol© 44, p. 805o a (l) The results show that in the first determination with the subject seated there was a decrease in the diastolic and systolic volume from normal of 14$ and 12$ respectively after 2 minutes of breathing against a positive pressure of 30 - 35 mmv Hg and that after 25 minutes the decrease was essentially the same. At this time the diastolic volume was 16$ end the systolic volume was 14$ below the normal© The stroke output decreased 27$ and 26$ respectively after 2 minutes and 25 minutes of breathing against this positive pressure® On the other hand, the pulse rate increased from 100 to 140 and remained constant at 140 so that the minute output was not changed from normal while breathing against 30 - 35 mm# Hg positive pressure* (2) The results show that in the second determination with the subject seated, the roontgon kymogram taken 27 minutes after breathing against 30 - 35 mm, Hg showed changes essentially the some as in the first determina- tion. It can bo soon that the diastolic volume decreased 18$ and systolic 1T$ from normal© The stroke output showed 30$ decrease from normal but again the minute output remained practically the same as the normalo (3) The third determination taken in tho erect position showed more marked decrease in diastolic and systolic volume and stroke output, but again an increase in the pulse rate compensated for tho decreased stroke output so that tho minute output remained essentially the samoc b© Exhibit 3 shows two superimposed heart tracings. The tracing in solid lino shows tho normal heart silhouette and tho dotted lino shows tho heart silhouette 25 minutes after onset of positive pressure breathing© C© Conclusion© The observations made at different times on a single subject breathing against 30 - 35 urn* Hg in the positive pressure jacket for as long as 27 minutes show, at least in this individual, that although there is a marked decrease in diastolic and systolic volume and the stroke output of the heart, the increase in the pulse rate compensates for the reduced stroke output so that the minute output remains the some while breathing against positive pressure as that ob- tained under normal conditions« / Prepared by Eldon W. Erickson, M0D» J> P0 Marbargor, 2nd Ltw A«A.>F« C tt Bp Taylor 9 1st Lb a Mep0 Approved by E« J0 Baidas, PhoD« Charles F» Code* MQD© Distribution} Commanding Officer Attention Col# 0, 0* Benson, Jr9 Aero Medical Research Laboratory Wright Field, Dayton, Ohio Office of the Air Surgeon Attention Col. Loyd E. Griffis Washington, D.C© Series Ap No. 4 o* jDBTERMINATION # 1, Subject sitting, in the j positive pressure jacket*, j i ;The positive pressure used was 30 - 35 mm* Hg and the |Diastolic 1 Systolic exposures were made under | area | area the following conditions: | (sq.cm*) j (sq* cm*) Diastolic volume ( oo* ) j 1 i < Systolic ; Stroke volume | output ( CO* ) 1 ( CCc ) Pulse rate Minute output (L,/rainr>) A. Control* No positive pressure,Subject seated* ; 112*6 j 101*4 i 1.1 i 603*7 . 518,8 j 84.9 .. . 100 0*49 iB* After 2 minutes breath- t 101*5 , 93*0 ing against 30 - 35 mm*Hg | i I 519.5 (-14#) 457.7| 61,8 (-12® i (-27#) i 14C 6V,65 (+2/$) jC, After 25 minutes breath- ; 100*0 j 91c3 506c4 ing against 30 - 35 mm*Hg ] | (-165$) 1 . : .--■-L j — 1 445c5 (-145$) s 62.9 (-26#) — ■ . 140 — 8.81 (+4#) i DETERMINATION# 2a Am Control* No positive j 11407 | 104*9 j 620c2 j 544*9 i pressure,subject seated* 75*3 100 7*53 B* After 27 minutes breath- \ 99*6 j 92c4 ; 505*2 • 453c3 ing against 30 - 35 mm*Hg | j 1 (-185$) i (-175$) '' ! L _ ■51.9 (-«•#) 7,79 (+3#) # 3*' ' j |A* Control* Subject standing, j 114,2 i 102*9 ; 616,4 I 630*2 | 86*2 in positive pressure jacket^ 100 8*62 ;Bu After 2 minutes breathing j 92*8 " \ 462,2 | 410*0 j— against 30 - 35 mm, Hg j ; j (-255$) j (-235$) 1 (-405$) i : —*4— -4*- i ! 1 170 i 8,77 (+25$) The percentages indicate the changes from the normal. Exhibit 2 Subject* J. P. Marbarger Age 26 Surface area - 2*2 square meters Anterior-postericr diameter of chest - 24 centimeters Correction for each x-ray distortion - *7545 Series A, No* 4 c* MAYO AERO MEDICAL UNIT ROCHESTER, MINNESOTA area Diastolic area Exhibit 3* Two superimposed heart tracings The tracing in solid line shows the normal heart silouette and the dotted line shows th the heart silhouette 25 minutes after onse-t of positive pressure breathing. C.B.Tayler and J, P.Marba’’ger March, 1943 Chart XIX—7d MAYO AERO MEDICAL UNIT MEMORANDUM REPORT to ARMY AIR FORCES MATERIEL CENTER Under Contract No* w£35ac-25829 SUBJECT: Progress on arterial puncture studies at altitude breathing against positive pressure in the positive pressure jacket* SERIAL REPORT: Series A, No« hd. DATE: March 3, 19U3 A. Purpose* Weekly progress report on arterial punctures at altitude. B. Factual Data, 1, To date we have at hand the results of the following: 2 arterial punctures at ground level breathing against 8 in. (21 cm. water). 5> arterial punctures at U6 ,000 feet breathing against 8 in* (21 cm. water). 1 arterial puncture at Ul,000 feet breathirg against 8 in. (21 cm, water). 1 arterial puncture at Ul,000 feet breathing against no positive pressure, 3 arterial punctures at U6,000 feet breathing against 0 cm, water. 2 arterial punctures at U6,000 feet breathing against hS cm. water. 1 arterial puncture at £0,000 feet breathing against U5> cm. water. h venapunctures at U6,000 feet breathing against 8 in. (21 cm, water), 1 venapuncture at 146,000 feet breathing against U5 cm, water. Six subjects were used in these experiments• We expect to complete this work by Monday, March 8, 19h3, and to submit a complete report of our findings very soon thereafter. 2. We are obtaining some electrocardiographic and electroencephalographic studies with the positive pressure jacket at ground level and at altitude breathing against 20, 30 and UO cm, of water. 3. We are deeply indebted to Dr. M, H. Power without whose willing cooperation in making the chemical analyses, etc, this investigation would have been impossible. Distributions Commanding Officer Attention Col* 0* 0. Benson, Jr, Aero Medical Research Laboratory Wright Field, Dayton,Ohio Prepared by: Charles B* Taylor, 1st Lt«McC, John P» Marbarger, 2nd Lt»A>A.F« Office of the Air* Surgeon Attention Col* Loyd E, Griffis Washington, D, C, Approved by:E« J, Baldes, Ph.D. Cn F* Code, M«D* MaYO AERO MEDICAL UNIT MEMORANDUM REPORT to army air forces materiel center Under Contract No„ w£3£ac-25>829 SUBJECT: Arterial blood studies at altitudes up to 50>000 feet, breathing under positive pressure in the positive pressure jacket. SERIAL REPORT: Series A, No. U e DATE: March 11, 19 U3 a. Purpose. 1, To report on the determinations of arterial oxygen saturation made under the following conditions: a. Breathing under 20 cm. (8") water positive pressure in the positive pres- sure jacket at ground level, Ul,000 and U6,000 feet. b0 Breathing under no positive pressure at Ul,000 and I|6,000 feet. c. Breathing under an average of Uii cm. water positive pressure in the pos- itive pressure jacket at U6,000 and 50,000 feet*. 2. To report on the pH and carbon dioxide content of arterial blood under the above mentioned conditions. 3. To report the correlation between the arterial oxygen saturation and the oximeter readings (Coleman model 17, no. 5769) under the conditions mentioned above. U. To submit a report of the chamber flights made to obtain the arterial samples needed for this investigation. B. Factual data. 1. Apparatus and method. a. Ten cubic centimeter samples of arterial blood were taken from the femoral artery under oil in a syringe containing a bead for mixing, and a little heparin as an anticoagulant. As soon as the sample was collected the needle (20 gage) was inserted into a rubber cork. The sample was mixed 2 or 3 times and then put into ice water. Then it was immediately put into the air lock, dropped to ground level and pH and gas determinations were made as soon as possible. Determinations of pH were made at 38° by means of a jacketed capillary glass electrode as described by Dill, Daly and Forbes1 in conjunction with a Coleman Model U pH meter the scale of which read to 0.1 millivolts. The glass electrode was calibrated with suitable phosphate buffers before and after each blood pH determination. Although some slight decrease of pH may have occurred in the time interval between the collection of sample and the detenuinations of pH. This is believed to have been very small and the pH values are presented as obtained without corrections. The Van Slyke and Neill manometric method was used for gas analysis. While each sample of blood was drawn, oximeter readings were taken simultaneously with the use of a Coleman oximeter set at 100 per cent while breathing oxygen under 20 cm. (811) water pressure0 1. J.B.C,, Vol. 117: 569, 1937. In most of the chamber runs the subjects breathed against 10 to 20 cm. water pressure from ground up* The samples obtained while breathing against no positive pressure and an average of 1*1* cm, positive pressure were collected after the pressure had been regulated at altitude® Appendix I shows a complete description of the log of each trip* Different periods of time at altitude were allowed before the arterial punctures were made* These data are found in Exhibit 1, 2. Results* a* The results of the arterial blood oxygen are presented in tabular form in Exhibit 1* The results of 10 punctures at 1*6,000 feet and breathing against 20 cm* (8n) water positive pressure show that the range in arterial oxygen saturation (by chemical analysis) was from 87.1* per cent to 69*1 per cent, the average being 77<>6 per cent. At 1*1,000 feet and breathing against the same pressure the arterial oxygen saturation (1 case) was 90*3 per cent and when the pressure was reduced to 0 the saturation was 89.9 per cent* The table shows that at 1*6,000 feet when the pressure under which the subjects were breathing was reduced from 20 cm. (8U) water to no pressure, the arterial oxygen saturation (3 cases) ranged from 71*9 per cent to 56o3 per cent, the average being 67*1 per cent. Exhibit 1 shows that at 1*6,000 feet when the pressure against which the subject (1* cases) was breathing was increased from 20 cm, to an average of 1*1* cm0 water, the arteriaL oxygen saturation ranged from 95.6 per cent to 88,0 per cent, the average being 93.9 per cent. At 50,000 feet the table shows that the arterial oxygen saturation ranged (1* cases) from 92.0 per cent to 75*7 per cent, the average being 80*3 per cent. b. Exhibit 2 shows a curve for arterial blood oxygen saturation at altitudes up to 1*1*, 000 feet breathing pure oxygen without pressure* This was taken from PHYSIOLOGY OF FLIGHT, fig. 8, p, 13, 191*0-1*2, Wright Field, Dayton, Ohio. The data for arterial blood oxygen saturation found in Exhibit 1 was then added to this graph. See Exhibit 2 and legend for further descriotion. c. Positive pressures of 15 ram. Hg (20 cm. water) and 32.5 mm. Hg0(i*l* cm* water) actually increases the effective alveolar oxygen tension. Hence under these conditions one would expect an arterial oxygen saturation equivalent to the satura- tion found in fig. 8, p, 13, of PHYSIOLOGY OF FLIGHT, at altitudes with a barometric pressure 15 mm. Hg and 32*5 mm. Hg lower. With this in mind in Exhibit 3 we shifted the curve found in PHYSIOLOGY OF FLIGHT, 15 mm. Hg and 32,5 mnu Hg to the right. This curve shows that the results we obtained at 1*6,000 and 50,000 feet lie within the anticipated range. See Exhibit 3* d. Exhibit 1 shows the pH determinations and the carbon dioxide content in volumes per cent for each sample. It can be seen that at 1*6,000 feet and breathing under 20 cm. (8M) water positive pressure the pH values (10 cases) and carbon dioxide contents ranged from pH 7.1*2, 1*3.10 vol, % to pH 7.1*9* 1*8,65 vol. %* The average pH and carbon dioxide content values were 7.1*6 and 1*6.ll* respectively. At 1*1,000 feet with and without positive pressure the pH values were the same, 7.1*1, and the carbon dioxide contents were 1*6,70 and 1*5.70 vol* % respectively. At 1*6,000 feet with no positive pressure (3 cases) the ranges of the pH values and carbon dioxide contents were pH 7.1*6, 1*2.07 vole % and pH 7.1*8, 1*8.20 vol* % respectively. The averages were pH 7.1*73 and 1*1*.18 vol, %, At 1*6,000 feet with an average of 1*1* cm., water positive pressure the ranges were (1* cases) pH 7 <-1*5* 38r.87 vol, % and pH 7.52, vol* %9 The averages were pH 7.1*87 and 1*2.1*8 vol. % respectively. At 50,000 feet with 1*1* cm. water positive pressure the ranges (1* cases) were from pH 7.1*6, 39.38 vol. % to pH 7o55, 1*1*.51 vol. %• The averages were pH 7.1*82 and 1*2,39 vol, % to pH 7*55, 1*1*.51 vol, %, The averages were pH 7,1*82 and 1*2.39 vol. According to Gibbs et al., (J.B.C, Vol. lUU, No. 2, 19U2, p. 325) in the study of 5>0 normal males in resting condition the range for arterial pH was from 7.37U to pH 7.U55* The carbon dioxide contents ranged from U5.6 vol. % to 50.U vol. The averages were pH 7.U2U and U8.2 vol. % respectively. Our results show that in positive pressure breathing there is a tendency towards an increased pH and a decrease in carbon dioxide content compared with the work of Gibbs et al mentioned above. Peters and Van Slyke (Quant. Clin. Chem. Vol. 1, Williams and Wilkens Co., 1931, p. 9U2) content that tetany is not likely to occur until there has been a rise of at least 0.2 pH units. It has been our experience that during the first 5 minutes after pressure is instituted one tends to hyperventilate in the positive pressure jacket. This also occurs if the pressure is increased from 20 cm. to UU cm. water, ©ample 5, subject H. Haglund, 3/5/U3 (Exhibit l) demonstrates this temporary rise in pH and fall in carbon dioxide content at the beginning of positive pressure breathing. Sample 8, subject H. Haglund, 3/5/U3, taken on the same day breathing against the same pressure but 17 minutes later shows a rise in carbon dioixide and a decrease in pH to an essentially normal level. This is more strikingly shown in samples 5, 6, 7 and 8 (Exhibit l) subject C. B. Taylor, 3/3/U3 and 3/6/U3* This work shows that there is a temporary alkalosis during positive pressure breathing which is probably not danger© us and which disappears after a few minutes of adaptation to positive pressure breathing. e. Oximeter readings were carefully taken simultaneously with arterial punctures. Except for a possible slight venous stasis of the ear (necessary because the mask had to be firmly fixed to the face) conditions f or accurate oximeter readings were ideal. In Exhibit U oximeter readings are plotted against arterial blood oxygen saturations determined by chemical analysis. Exhibit U also contains a table of points plotted and of the error of tbs oximeter for each of the 23 samples. Except for 5 oximeter readings which proved to be very inaccurate, the oxiraiter checked quite well with the arterial blood oxygen, saturations. Exhibit U also suggests that the oximeter used (Coleman Model 17, No. $769) is fairly accurate for arterial blood saturations above 75 to 80 per cent but is quite inaccurate when the arterial saturation falls below this level. f» The logs of the 12 flights made in obtaining the arterial punctures may be found in chronological order in Appendix I. The first page of each log contains the oximeter readings made during the flight, the second a record of denitrogeniza- tion and all pages after that a running record of the flight. A few interesting points of the flights might be made: l) an altitude of U6,000 feet was easily tolerated by the subject (H.R.) and observer (J.P.M.) for 22f min.5 2) an altitude of 50,000 feet was easily tolerated by subject (C.B.T.) and observer (J.P.M.) for almost 18 minutes; 3) the observer during all flights to both U6,000 and 50,000 feet walked around in the chamber and moved all boefy parts as freely and with as much ease as if at ground level; U) the observer (J.P.M.) of all the flights (9 flights to 1*6,000 and 2 flights to 50,000 feet in this series) only once experi- enced very mild bends in his right hand after \ hour at U6,000 feet. He had been holding his hand over the femoral artery of the subject most of the time at altitude and had been compressing the artery and moving his hand considerably, while obtaining the sample. 5) It can be noted from the logs of the flights that a number of subjects had trouble keeping their ears open on descent. This was due to the fact that the subjects were lying on their backs and in all cases the difficulty was corrected when they sat upc 6) One subject (C.B.T.) who has very frequently developed severe gas pains during many flights to 35,000 feet to U2,000 feet while wearing a constant flow or demand mask has experienced no gas pains during one flight to Ul*000 3 flights to U6,000 and 2 flights to 50,000 feet in the positive pressure jacket. The pressure of the jacket around the abdomen seems to prevent the distention of the intestines which occurs as the gas in the on ascent, and instead forces it into the sigmoid colon where it is easilj&expelled. C. Summary. l.The average arterial blood oxygen saturation (by chemical analysis) of 10 blood samples taken at 1*6,000 feet while breathing 20 cm. (8”) water positive pres- sure in the positive pressure jacket was 77.6 per cent, while breathing against 1*1* cm* of water, 93.3 per cent and while breathing against 1*1* cm* water in the positive pressure jacket at 50,000 feet the average arterial oxygen saturation was 80,3 per cent* 2* During the first 1* or 5 minutes of positive pressure breathing or during the first 1* or 5 minutes after positive pressure is increased from 20 to 1*1* cm* water, the subjects, in becoming adjusted to the pressure, show a tendency towards a mild alkalosis (indicated by blood pH and carbon dioxide content studies)* This is due to temporary hyperventilation* The degree of alkalinity does not approach those levels of tetany* Arterial blood chemistry studies after 5, 10, 15 and 20 minutes of positive pressure breathing at altitude show that after 5 minutes of positive pressure breathing the blood pH and carbon dioxide content almost approach normal« 3# It was found that oximeter readings check quite well with the arterial oxygen per cent saturation (23 samples) chemically analyzed to a saturation of 75 to 80 per cent. They do not check very well below this level. D, Recommendations* 1* The results of arterial blood oxygen saturations, pH determinations and carbon dioxide content determinations done on blood samples collected at 1*6,000 and 50,000 feet while breathing in the positive pressure jacket show that the jacket is a veiy definite improvement over present oxygen equipment for altitudes above 1*0,000 feet* An exhaustive study of its possibilities and further investigations as to its application for military flying personnel sh ould be seriously considered* 2. It is recommended that positive pressures of 30 cm, of water be used in preference to 20 cm, of water because an altitude of 1*6,000 feet can be maintained more comfortably and for a longer period of time. The pilot will also be more efficient* We do not believe that positive pressures up to 1*5 cm, of water are harmful to the pilot but the difficulty of keeping the mask to the face makes it somewhat uncomfortable. Distribution: Commanding Officer Attention Col. 0.0,Benson, Jr, Aero Medical Research Laboratory Wright Field, Dayton, Ohio Prepared by M* H* Pov/cr, Ph.D0 C» B. Taylor. 1st Lt., M«jG« J. P» Marbarker, 2nd Lt», AAF Not present when report submitted Office of the Air Surgeon Attention Col. Loyd E. Griffis Washington, D. G, Approved by E. J, Baldes, PhJ)0 G* Code, MJ)o Tine at alt. * Arterial blood Sample No. Sub J o Date Altitude in feet Pos. press. cn,H20 breathing agnst. pres*, before punc- ture started C? content Vol, % (Note) °2 capacity Vol. % o2 sat. % i (chemical analysis) °P sat. $ i(oxi- meter) co2 con- tent Vol PH 1 2 3 h 5 6 7 8 9 10 11 CBT CBT CBT WLB HH HH RE lih RE WLB RE 2/16/1+3 2/23/1*3 2/26/1*3 2/22/1*3 3/5/U3 3/2/U3 3/2/1*3 3/5/1* 3 3/5/l*3 3/3 A3 3/5/U3 ill, 000 1*6,000 1*6,000 1*6,000 1*6,000 U6,000 1*6,000 1*6,000 1*6,000 1*6,000 1*6,000 20 20 20 20 20 20 20 20 20 20 20 9.58 1.67 3.25 0.1*2 3.58 6.33 2.75 21.08 1.08 7.08 1.08 17.93 17.8 9 16.81* 16.87 15.1*2 16.12 U*.83 15.19 lU .21* 11*. 87 13.31 19.85 20.1*6 20,1*0 20.61* 19.73 20,89 19.33 20,17 19.20 20,2 5 19.25 90.3 87.1* 82.5 81.7 78.1 77.2 76.7 15.3 71*.2 73.1* 69.1 97 69 81* 83 79 83 89 7i* 89 7i* 89 16.70 1*3.10 1*1* .10 1*6.70 1*3.87 1*1* *56 1*7.61* 1*6.10 1*8 #1*1* 1*8.11* 1*8.65 7.1*1 7.1*6 7.47 7.1*7 1*.1*7 7.1*1* 7.U 7.1*1* 7.16 7.1*9 7.1*2 1 2 3 k CBT CBT CBT WLB 2/16/1*3 2/23/1*3 2/26/1*3 2/22/1*3 lily 000 1*6,000 1*6,000 1*6,000 0 0 0 0 1.97 1.08 2.17 1.75 17.1*6 H*.83 A.65 12.1*5 19.1*3 20.63 20.61 21.37 W.9 71.9 71.1 58.3 90 76 76 69 1*5.70 1*2.07 1*2.26 1*8.20 7.1*1 7,1*8 7.1*6 7.L6 1 2 3 h WLB CBT CBT RE nr>rn 3/3/1*3 2/26/1*3 2/23/1*3 3/5/U3 1*6,000 1*6, ooo U6'000 1*6, ooo liU 1*6 U3 UQ 1.92 1**00 1.00 0.50 19.69 19.31* 19.1*0 16.92 " 20,60 20.33 20.51 19.22 95.6 95.1 9l*.6 88.0 93 95 98 98 1*3.59 38.87 1*0,36 1*7.05 T3*9 7.52 7.1*9 7*1*5 6 7 8_ OBI CBT CBT CBT PQ'T' 3/3/l*3 3/6/1*3 3/6/1*3 3/6/l*3 " So,ooo 50,000 50,000 5Q,ooo 1*5 1*3 1*3 0.33 5.17 10.50 15.33 17.71* 15.78 15,75 15.69 19.29 20.57 20.50 20.72 92.0 76.7 76.8 75.7 93 77 76 77 39,38 l*U#5l 1*2.93 7.55 7.1*6 7,1*6 2 JM 2/8/U3 Ground Ground 20 20 10.00 i5.oo 20,80 22.70 “20,00 21.00 “lOl*.0 108.1 T6.30 M.. on l .uo 7.1*1 7 l.n * The samples were taken from by J. P. Marbarger, 2nd Lt. the femoral artery t A .A *F. - | «*4U Note: All but the two samples t b x < o F<> Office of the Air Surgeon Attention Cole- Loyd B, Griffis Washington,, D.C* Approved by Walter M» Conditions Diastolic area ( aq. cm*) Systolic area (sq* cm.) Diastolic volume (CO*) Systolic volume (cc*) Strike Pulse output rate (oc«) Minute output (j.;o/min0) Subject #1* Control® No positive pressure® Subject seated* 105ol 95*5 546*2 475*5 70c 7 : 110 7*78 Subject #1* After 5 minutes* Inspiratory pressure =; 22 mm® Bg0 Expiratory pressure =2 30 mm* Eg* 99»5 91c7 504*5 (-7.6%) 448,3 (-5,7$) 56*2 (-20*5?S) 120 6*74 (-*13,2$) Subject Jl* After 10 minutes® Pressures same as above0 95*1 88,5 472*5 (-13.5$ 426*1 (-10*4%) 46*4 v («s3404/£) 136 6.31 f (-18.9$' Control No positive pressure* Subject seated® 125*0 109*9 702o6 582*9 119*7 A CCi 9*56 Subject $2* After 5 minutes* Inspiratory pressure =2 22 mm* Hg» Expiratory pressure =3 28 mm. Hg0 111*0 102*1 591.4 (-15,8*) 524cl (-10.1$) 67*3 (-43eC^) 100 6.73 (-29,7$) Subject if3® Control® No positive pressure® Subject seated* 115*7 104*4 628*1 541*0 8701 100 8*71 Subject #3* After 5 minutes. Inspiratory pressure =2 20 mm* Eg® Expiratory pressure =2 25 mm. Eg* 115*3 106*0 624*9 (*-0* 5°/o) 553*0 (+2.2$) 71.9 (-17.5$) 100 7.19 (-17,5$) The percentages indicate the changes from the normal* EXHIBIT 1 RESULTS OF CARDIAC OUTPUT STUDIES ITSmTTHE*POSITIVE PRESSURE REBREATHER BAG MAYO AERO MEDICAL UNIT Rochester, Minnesota LIAISON REPORT NO* 4 he May 6, 1943 SUBJECT* Report of Liaison Officers, 1st Lt© C, B* Taylor* M.C,, aid 2nd Lt, J. P. Marbarger, A,A,F«« attached to the Mayo Aero Medical Unit for activities from April 19 to May 5, 1943a TO* Office of the Air Surgeon** Washington, D,C0, and Chief, Aero Medical Research Laboratory, Wright Field, Dayton, 0h&o3 FACTUAL DATA* 1* After returning from Yfright Field several arterial punctures were tried during the week of April 19 with the new Bendix #17 pressure regulator*, In all of the runs electrocardiograms were obtained on the sub- jects which will bo evaluated in a subsequent report. During two of the runs the subjects got into difficulty at oh-oitdde and had to come down and in one the operator missed the puncture. Consequently no blood samples were obtained during that week. 2, It was observed that the Bendix #17 regulator did not function quite properly. The disc covering the exhaust valve did not seat properly with the result that it was impossible to hold pressure at altitude. This was overcome for a time by reseating the disc manuallyc With continued use* however, the disc again became displaced and had to be reset© It was thought best to return it to Wright Field and if possible exchange it for another regulator. 3, A series of arterial blood gas analyses were made at ground level. These results will be presented in a subsequent report. 4© During the week of April 25 Dr, Clark, flight surgeon. Willow Run Bomber Plant, brought test pilot, Murray Hawley, here for high altitude indoctrination. They were preparing to take the Thunderbolt to ceiling and therefore they were interested in positive pressure breathing. Pilot Hawley was indoctrinated in pressure breathing and made several flights to 46,000 feet, using the positive pressure vest and the Emerson regulator; he made one flight to 50,000 feet with positive pressure vest. 5* A series of arterial punctures were performed on PilotHawley at 46,000 and 44,000 feet using 8 inches water positive pressure as delivered by the Emerson regulator** Electrocardiograms were also obtained on him* These results will be presented in a subsequent report* It was observed that there was extreme fluctuation in pressure using this regulator and the sub- jects respiratory rate was only nine times per minute* Blood gas analysis after seven and seventeen minutes showed a rather high pH and corresponding high oxygen saturation and low carbon dioxide content* It was thought that this was due to the extreme pressure fluctuations and since subjects are limited no further blood work was deemed advisable until the regulators come from Wright Fieldc a 6* A pneumograph was constructed to continuously record the respiratory rate of the subject* In order to record the respiratory rate simultaneously with electrocardiogram records and oximeter readingsr an improved set*-up with pneumograph was arranged which will bo used as soon as the positive pressure regulator arrives from Wright Field* Addendums This afternoon with the use of Professor Akerman* s pressure suit with 2g- lbs* pressure plus the Emerson positive pressure regulator delivering oxygen under a differential pressure of 7 inches of wauer J0 P<, Marbarger went to a pressure elevation equivalent of 56.964 feet corrected and remained above 60p000 feet for 16 minutesfl MAYO AERO MEDICAL UNIT Walter M* Boothby, M,D», Responsible Investigator Memorandum Report to Army Air Forces Materiel Cencer Under Contract No. W535~ac-25329 SUBJECT* Arterial blood studies at altitudes of 44*000 and 46,000 feet, breathing under positive pressure with the Wright Field positive pressure mask and regulator developed by Major A, P. Gagge, A,C0, and his group0 Serial Report* 4 j Date* May 1943 Am Purpose 1, To report on the arterial blood oxygen and carbon dioxide contents and partial pressures of arterial blood taken at 44,000 and 46,000 feet while the subject was breathing under eight inches of water or 15 mm*. Hg positive pressure with the Wright Field pressure mask and regulator. a» To report the pH*s of arterial bloods taken under the conditions mentioned above* 2# To report on throe oases of circulatory collapse during positive pressure breathing with a mask only. B. Factual Data 1, Apparatus, aa For details of technique and chemical procedures used see Serial Report, Series A, No. 4 c on arterial blood studies at altitudes to 50,000 feet, breathing under positive pressure in the positive pressure jacket, March 11, 1943. b. For details on determinations of the partial pressure of oxygen and carbon dioxide see under (2) Factual Data of the preceding report. 2, Results, fx0 In Table I the results of the chemical analyses of the (13) blood samples taken at 46,000 and. 44,000 feet and the condition of the ex- periments are listed in tabular form. bD The average arterial oxygen saturation of the twelve samples taken at 46P000 feet while the subject was breathing under eight inches of 7/ater or 15 mm, Hg positive pressure, was 78,0$ and ranged from to 84,7$ saturation. The average arterial oxygen saturation of five of the samples taken after five minutes at feet was 77cl$ and ranged from 68<>9$ to 84*7$ saturation. One somple at feet with the subject breathing under 13 mm, Hg positive pressure showed on arterial saturation of 8 8 n 5%c Co The pH‘s and contents were slightly toward the sift© of alkalosis but a long way from the danger level. For a more detailed discussion of the dangers of tetany of alkalosis see paragraph (d) under Results (2 of Factual Data) in Serial Report, Series A, No® 4 c., March 11, 1943® do In Table II can be found the partial pressures of Og and COg* The pOg, PCOg, and water vapor tension have been totaled and can bo compared with the barometric pressure at the time the sample was taken plus the posi- tive pressure under which the subject was breathing* It will be noted that here too the two totals approximate each other very well0 o® It is of interest that one of our subjects* age 18* who had participated in all athletics in high school and college and had been accepted as a Navy Aviation Cadet and who, as far as physical examination revealed,,* was a healthy young male, developed a severe bradycardia after not more than one- half hour of positive pressure breathing of eight inches of water or 15 mm? Hg with a mask only. Electrocardiograms were being taken incidental to the arterial punctures; the subject?s pulse rate, immediately after positive pressure breathing was started, rose to 96;. but while at 46*000 feet not more than one-half hour after pressure breathing was smarted it slewed to 45 per minute and collapse became imminent; ho was immediately brought to ground level and the positive pressure breathing was discontinued® Electrocardiogram, tracings showed marked bradycardia with no evidence of heart block® Mg have observed this reaction twice previously while subjects were breathing under twleve inches of water or 22g- mm* Hg at ground level,, One of these two subjects approached collapse in less than five minutes. His pulse rate normally 70* was 42 per minute and did not return to normal until five minutes after pressure breathing with mask only had to be discontinued. The other subject came near collapse after ton minutes of positive pressure of 22g- mm. Hg* His pulse was not observed® Both of these subjects were apparently normal healthy males on physical examination. Conclusions 1» Subjects breathing under eight inches of water or 15 mm0 Hg positive pressure at 46,000 feet have an average arterial oxygen saturation of 77o0% to 78.0/£ (by chemical analysis)® 2® The COg contents and pH*s suggest that alkalosis from hyperventilation while breathing under positive pressure is not a serious problem® It can be noted (Table I) that after periods of as long as 23|- minutes at 46,000 feet the pH and COg contents remained very near the normal levels® 3® It might be assumed from the totals of partial pressure of O2, COg, and water vapor, compared with the barometric pressure plus the positive pressure that the partial pressures of Og and COg reported in Table II are good approx- imations of the partial pressures of those gases that existed in the lungs at these altitudes of 44,000 and 46,000 feet® 4® Observations reported in Serial Report, Series A, No® 4 g to Army Air Forces Materiel Center, and from the observations reported in paragraph (e) under Results in this report, suggest that circulatory collapse may be a serious hazard in the use of the positive pressure mask and regulator with eight inches of water or 15 mm® Hg positive pressure without the support of a pneumatic vest of some sort over the chest and abdomen0 Recommendations lc Paragraph 4 under Conclusions above suggests that more extensive studies of the cardiovascular response to positive pressure breathing without a positive pressure vest should bo carried out. A maximum level of positive pressure without counter pressure chest support which normal individuals could tolerate for long periods of exposure should bo determined:, It is our impression that eight inches or 15 nun, Hg positive pressure in a mask without chest and abdominal support will cause on appreciable number of oases of circulatory collapse in relatively short periods of time (-§• to 1 hour)® Prepared by M0 He Power Ph*Do C» B,, Taylor, 1st Lt«j M,,C0 J, Pp Marbargerg 2nd Lt0 A«A«F;> Subject Altitude in 1000 of feet Pos, pres- against which subj, breathed in mm* Hg Time after attaining alt* before • puncture was done 02 content Vol* % (Note) °2 capacity Vol*^ Arterial Blood c2 o2 *.c2 saturation saturation content $( chemical % oximeter Vol*$ analysis) pH C #B•T, 46 15 20 sec* 16c4 19*6 63*6 85 43 a 7 7*62 C e B e T c 46 15 16 min© 14*9 19*5 76*6 81 45*0 7046 D*B, 46 16 2 min0 45 sec* 15,0 18*8 79*7 78 47*3 7o4S S0A« 46 15 3 min* 15*4 19*0 80*9 79 42*9 7044 DaiJ 46 15 2 min* 3C sec* 14*3 18*7 76*3 78 49*7 7*43 D»33a 46 15 19 min* 1302 19*1 68*9 73 49*2 7*4^ J.M. 46 15 3 min© 16*5 20*6 80*0 83 46*0 7*46 J.M. 46 15 22 min* 17*C 20*6 82*2 77 45*0 7044 H.H* 46 15 3 min* 35 sec* 1407 19*4 75*8 77 45cl 7*44 R*B. 46 15 3 min* 40 sec© 1364 17*8 75*0 77 4605 7043 R«E* 46 15 23 min* 35 sec* 12*7 17*3 73*0 78 46*8 7*44 M.H* 46 15 7 min* 45 sec* 17*6 20o7 84*7 86 44*8 7*51 M.H. 44 13 4 min* 23 sec* 18*6 21*0 88*4 91 4406 7049 TABLES II A ARTERIAL BLOOD OXYGEN STUDIES USING THE WRIGHT FIELD POSITIVE PRESSURE REGULATOR AND MASK TABLE II B Gaseous pressures of arterial blood using Wright Field positive pressure regulator and mask. Total of partial pressures of oxygen, carbon dioxide, and water vapor compared with the barometric pressure plus positive pressure* . . Sub.iect Altitude in 1000s of f*t & barometric pressure Positive pressure in mm* He Calculated partial pressure of gases in whole arterial blood (mmcHg) Total 3ar9 iu + posfl p* ram« Hg ?C0? pH90 Total of pCOgfPOg, & pH90 C »B © To 46 (JOS) 15 121 28-.1 44 47 119 C a B oT • 46 (106) 15 121 31 40 47 118 D.B. 46 (106) 15 121 33 42 47 122 S • Ao 46 (106) 15 121 32 45 47 124 Do Do 46 (106) 15 121 38 41 47 126 D.Do 46 (106) 15 121 41 36 47 124 JoM® 46 (106) . 15 121 34 43 47 124 J.M* 46 (106) 15 121 34 46 47 127 H.Ho 46 (106) 15 121 34 40 47 121 R.E* 46 (106) 15 121 36 40 47 123 H*E* 46 (106) 15 121 35 38 47 120 Mc Ho 46 (106) 15 121 30 46 47 123 Me Ho 44 (115) 13 128 31 52 47 130 liayo Aero Medical Unit Walter M. Boothby, M.D., Responsible Investigator Memorandum Report to Army Air Forces Materiel Center Under Contract No. W5>3!? ac-25>829 SUBJECT: 1* Some preliminary observations on the partition of the total respira- tory volume during positive pressure breathing with and without the counter-support of a pressure jacket. 2. Some preliminary observations on the effect of pressure breathing on the oxygen saturation of arterial blood., Serial Report; U k Date; May 19U3 As Purpose 1, To report the effect of positive pressure breathing with and without a positive pressure vest on the partition of the total respiratory volume. A study of three cases at ground level. 2. To report preliminary studies on the effect of positive pressure breathing (without a positive pressure vest for counter support) on the per cent of oxygen saturation of arterial blooda B, Factual Data 1* Apparatus and Methods a* To study the partition of the total respiratory volume during positive pressure breathing without the counter support of a pressure vest a recording spirometer was placed inside a compression chamber0 The outlet of the spirometer was brought outside the chamber and connected with the Wright Field Pressure Mask* The recording spirometer was filled with oxygen; there was no CC>2 absorbing cannister in the system* The subject stood outside the chamber and respired into and out of the spirometer inside the chamber at 0, 10, 20, 30 and h0 cm. of water compression of the chamber; records of tidal air and the vital capacity were obtained. The partitions of the total respiratory volumes were calculated from the tracings obtained as described above; they were obtained within the first minute of positive pressure breathing at each level of positive pressure. Rest periods of from three to give minutes were allowed between each level of positive pressure breathing. To study the partition of the total respiratory volume during positive pressure breathing with the counter support of a pressure vest the same procedure and equipment as above was used with the following addition: a pneumatic vest which covered the entire chest cage including the apices and the entire abdomen and back was connected to the compression chamber by means of two corrugated rubber tubes (inside diameter ij in«) with one way flutter valves operating in opposite directions. The pneumatic vest, therefore, exerted the same pressure on the chest and abdomen as that exerted on the lungs via the spirometer* b, To study the effect, if any, of positive pressure breathing without the counter support of a pressure vest on the per cent O2 saturation of arterial blood the following procedure and techniques were used: A large gasometer was placed beside the decompression chamber; it was connected by a large rubber tube diameter in. to a positive pressure mask inside the chamber which the subject wore* There was also an expiratory tube on the mask which led to the outside of the chamber* Each of these two tubes had appropriate one way flutter valves to control flow of inspiratory and expiratory air* The gasometer was kept at a con** stant level of fullness by flow from a cylinder of 13% oxygen* With equal barometric pressures inside and outside the chamber the subject breathed the gas mixture for seventeen minutes before the first sample was taken and thirty-four minutes before the second sample was taken* Next the chamber was decompressed to approximately l£ nn* Hg lower barometric pressure than that on the outside (see Table 1 for exact differences of pressures)* The subject was still breathing from the gasometer on the outside of the chamber which was subjected to exactly the same barometric pressure as it had been when the first two samples were taken without pressure breathing. Two blood samples were token each at least fifteen minutes after the subject had been breathing this gas mixture under a positive pressure of V~> mm. Hg. See Serial Report: Series A, No. i*E for details of collecting arterial samples and methods of chemical analysis* 2© Results a-. The results of the studies of the partition of the total respiratory volume during positive pressure breathing with and without counter support of a positive pressure vest havo been shown in graphic form (exhibits not available). It should be pointed out that all three of these subjects had been doing positive pressure breathing for several months at the time these studies were made* It should also be pointed out that each of the partitions of total respiratory volumes were determined from tidal airs and vital capacities taken before one minute of positive pressure breathing had elapsed at each level of positive pressure. You will note (see graphs) the marked and progressive increase with increased pressure in supplemental%nat developed in these short periods of time* It is demonstrated in the graphs that with counter support of a positive pressure vest these changes are much less marked. b. Chemical analysis of blood samples taken while a subject was breathing a oxygen mixture with and without positive pressure but with the same total barometric pressure in the lungs (see Table l) showed no increase in the per cent O2 saturation of the arterial blood during positive pressure breathing* Conclusions 1* Pressure breathing against 20, 30, and U0 cm* of water positive pressure with a mask only for periods as short as one minute produces definite changes in the supplemental air volume in subjects well trained in pressure breathing* This change is definitely improved by a positive pressure vest for counter support. 2, Positive pressure breathing in this one case did not increase the per cent saturation of arterial blood. Apparently in this one case the distention of to avoid shunting of blood through partially filled or collapsed alveoli which night result in incomplete aeration of the blood in the alveoli did not increase the per cent O2 saturation of arterial bloody Re c oraraendations 1« Since the partition of the total respiratory volume is markedly changed during positive pressure breathing with a mask only it seems logical that studies should be carried out on animals to investigate the possibility of the development of emphysema after repeated and fairly lengthy exposures to these conditions * 2, Counter support of the chest and abdomen should be seriously considered if positive pressure breathing is to be used extensively. 3, The possibility of the marked increase in supplemental air (which would produce marked distention of the lungs) producing mechanical obstruction of the great veins in the chest and interfering with right heart filling should be in- vestigated. Prepared by Cc Be Taylor, 1st Lte, M«C0 M* H* Power, Ph» Do Jo Pe Marbarger, 2nd Lt»,AAF Bar. Press, ram.Hg Pos. Press, mm.Hg Bar.P* plus Pos.P, Time breath- ing mixture before sample taken o2 con- tent °2 capac- ity °2 saturation $(chemical analysis) °2 satur- ation /' (oxi- meter) • co2 con- tent PH pC02 P02 pco2 Bar,P,-pH.O times 02% mm.Hg 725 0 723 17 min* U0 sec. 16.7 20,1 82.7 87 UU.9 7.37 uo.o 50.3 90.3 86.7 725 0 725 3U min, 23 sec. 17.0 20,2 8U.0 87 UU.7 7.38 39.1 51.2 90.5 86.7 709*3 15.7 725 16 min, 3 sec. 17.3 20.3 83.3 8U 1(3.2 7.1(0 36.3 53.0 89.3 86.7 710.U 1U.6 725 16 min, 33 sec. 17.0 20,2 83.9 62 1»3.0 7.39 36.8 5i.o 87.8 86.7 Table 1 The following four samples were taken from the same subject during the same experiment in the order they are listed and under the conditions listed. Subject C.B.T. Date of experiment U/27/U3. The subject was breathing 12.93$ O2 at ground level - with positive pressure during the 1st two samples and during the last two. Mayo Aero Medical Unit Walter M. Boothby, M. D., Responsible Investigator Memorandum Report to Army Air Forces Materiel Center Under Contract No. W£3£ac-25>829 SUBJECT: Partial pressures of oxygen and carbon dioxide of blood samples taken at simulated altitudes up to £0,000 feet, breathing under positive pressure in the positive pressure jacket. SERIAL REPORT: h 1 DATE; May 30, 19U3 A. Purpose 1. To report the partial pressures of oxygen and carbon dioxide of blood samples taken at altitudes up to £0,000 feet. 2. To report a comparison of the total of (l) partial pressure of oxygen, (2) partial pressure of carbon dioxide, and (3) partial pressure of water vapor to the total of (a) the barometric pressure at the time the sample was taken, and (b) the amount of positive pressure under which the subject was breathing* B. Factual Data 1. Apparatus and Method. a. For details of experimental conditions and techniques used in collect- ing samples and blood gas analyses see Serial Report: Series A, No. Uc to Army Air ForcesMateriel Center, Under Contract No. W £35ac-2£829o 2. The arterial blood O2 and CO2 partial pressures were calculated as follows; a. Partial pressures of oxygen were taken from: Oxygen Dissociation Curves for Human Blood, Curves based on data of Major Dill, Wright Field, Aero- Medical Unit, by Lt. Mason Guest, A.C., Mayo Aero Medical Unit, June 9, 19U2 (III-£A)e b. Partial pressure of carbon dioxide; The serum carbon dioxide tension of blood was calculated from the carbon dioxide content of whole blood using the procedure shown in figure 96, page 907, of Voir 1 in Peters and Van Slyke Quantita- tive Clinical Chemistry. This calculation is based on mean values; the factors necessary to make these calculations are the carbon dioxide content of whole blood, pH, oxygen capacity and per cent oxygen saturation. The pH scale is the ordinary pH scale. From the calculated serum carbon dioxide content and the pH of -whole blood the carbon dioxide tensions of blood were calculated from the following equation, Peters and Van Slyke, Vol. 1, C02 tension - COg content (Millijnols) 1) m CO2 content (millimols) 0.0591«' (iophi - 6,10) + 1 1 millimol CO2 s 2.226 volumes per cent 3c Results. a* The results of the partial pressures of oxygen and carbon dioxide are shown in tabular form in Table 1; they are listed in the same order and are a supplementary report on the samples reported in Exhibit 1, Serial Report: Series A, No. U e to Army Air Forces Materiel Center on March 11, • 1. In table 1 you will note the total of the partial pressures of CO2, 02 and water vapor in the arterial blood; you will also note the total of the barometric pressure at the time the sample was taken and the positive pressure under which the subject was breathing. 2. It is evident from the data in Table 1 that in most cases the total of the P°2> PCO2 and water vapor tension very closely approximates the total effective alveolar tension (barometric pressure plus posi tive pressure). Conclusions. Since (2) immediately above is the case it might be assumed that the partial pressures of O2 and CO2 reported in Table 1 are good approximations of the partial pressures of those gases in the lungs at these simulated altitudes of 1*1,000, U6,000 and 50,000 feet. Prepared by H. Power, Ph. D. C* E* Taylor, 1st. Lt., M. Cc J«, P. Marbarger, 2nd Lt, AAF y Table 1 Total of Partial Pressures of Oxygen, Carbon Dioxide, and Water Vapor Compared with the Barometric Pressure plus Positive Pressure. No* Subject Date Altitude in Positive Total of P-C02 P-02 P-Ho0 Total thousands of press in BoP. + in* mm. Hg pCOo^pOp ft0 and B*P. mm® Hg Pos* Po & pflgO 1 C tB oT» 2/16/1*3 1*1 (13l»o2) 15 11*9.2 38.2 62 U7 ranioTir" 11*7 _,2 2 C oB aT* 2/23/1*3 1*6 (105,7) 15 120*7 32,0 52 U7 131.-5 3 G ,B*T • 2/26/1*3 1*6 (105.7) 15 120*7 32*2 U5 U7 12l*«2 U W.L.B. 2/22/1*3 1*6 (105.7) 15 120*7 31*.1 UU U7 125.1 5 H„H* 3/5A3 1*6 (105.7) 15 120*7 31.8 Ul U7 119,8 6 H*H» 3/2 A3 1*6 (105.7) 15 120*7 31*.8 la U7 122.8 7 R oE« 3/2/U3 1*6 (105.7) 15 120*7 36*6 Ul U? 12l*.6 8 H,H« 3/5/U3 1*6 (105,7) 15 120.7 35,7 39 U7 121.7 9 RoEo 3/5A3 1*6 (105.7) 15 120*7 35,7 38 U7 120.7 10 W*L0B. 3/3 A3 1*6 (105,7) 15 120c? 33.6 36 U7 116-.6 11 R*E* 3/5 A3 1*6 (105.7) 15 120*7 39.0 36 U7 122cO 1 CoBoT® 2/16/1*3 1*1 (131*.2) 0 131*. 2 37.1 60 U7 lUUd 2 C,B*T. 2/23/1*3 1*6 (105.7) 0 105,7 30*2 35 Ul 112 c 2 3 C.BoT. 2/26/1*3 1*6 (105.7) 0 105.7 31.6 35 Ul 113.6 U WoLoB. 2/22/1*3 1*6 (105.7) 0 105.7 36.3 28 Ul 111*3 1 WoL«B, 3/3A3 1*6 (105.7) 32,6 138,3 30*3 76 Ul 153,3 2 C.B.T. 2/26/1*3 1*6 (105.7) 31*.1 139.8 25 A 70 Ul U*2A 3 C.B.T. 2/23/1*3 1*6 (105.7) 31.9 137-6 28.1 69 Ul ll*U.l U R«,E» 3/5A3 1*6 (105.7) 30.0 135.7 35.2 5U Ul 136.2 C.B.T, 3/3A3 50 (87,3) 33.3 120.6 23.9 56 Ul 126,-9 6 C.BoT. 3/6/U3 50 (87.3) 33.3 120,6 33.2 Uo Ul 120,2 7 C.B.T. 3/6/l*3 50 (87.3) 31.9 119 o 2 32,0 Uo Ul 119 c0 8 C«B.T. 3/6/U3 50 (87.3) 31.9 119 c 2 32.0 39 Ul 118.0 1 C oB e T* 2/8 A3 Ground 15 38.0 2 JcP.M. 2/8/l*3 Ground 15 — 37.0 Mayo Aero Medical Unit Walter M. Boothby, M.D., Responsible Investigator Memorandum Report to Army Air Forces Materiel Center Under Contract No. W£35> ac-2^829 SUBJECT: A comparison of per cent saturation of arterial blood by chemical determin- ation, to per cent saturation of arterial blood as determined by the oximeter3 SERIAL REPORT: U m DATE: June 19U3 A. Purpose 1. To report the correlation between per cent saturation of arterial blood (as determined by chemical analysis) and oximeter readings (Coleman Model 17, No, $769) under the following conditions; a. Breathing under positive pressure at altitude (32 arterial blood samples and oximeter readings), b. Breathing gas mixtures low in O2 under positive pressure at ground level (two samples)* c. At altitude breathing 100$ O2 with no positive pressure (four samples)* d« Breathing gas mixtures low in O2 at ground level with no positive pressure (two samples)* B. Factual Data 1. These U0 arterial samples and oximeter readings were taken while studying arterial blood ©2 saturations during different types of pressure breathing. For details of technique and chemical methods, see Serial Report, Series A, No. 4c under Factual Data, Results and Conclusions 1. The results are reported in graphic form (exhibit unavailable). 2. It can be noted (l) that 33 of the oximeter readings correlated + or - 5$ with arterial blood O2 saturation per cent determined by chemical analysis, (2) five of the oximeter readings were very different from arterial blood O2 saturation per cent determined by chemical analysis, (3) that the oximeter had a tendency to give a higher arterial blood O2 saturation per cent than the saturation per cents determined by chemical analysis. Prepared by F. J. Robinson, M. D. C. Bo Taylor, 1st Lt., M. Ce Mo H, Power, Ph0 De Jo Pa Marbarger, Ph» D» MAYO AERO MEDICAL UNIT ARTERIAL BLOOD OXYGEN CONTENT DETERMINATION VS OXIMETER READINGS COLEMAN OXIMETER-MODEL 17, NO. 5769 ARTERIAL BLOOD OXYGEN (PERCENT CONTENT SATURATION] OXIMETER OXYGEN PERCENT SATURATION HI- 8 Ca Power,Taylor ,Marborger March, 1943