[music] Snow, cold rain, mud, these conditions lead to trench foot especially when menare immobilized or crouched in wet cold foxholes for hours. Constricting clothing and tight shoescontribute. Trench foot ranked highin military importance. When there wasconsiderable combat activity on the Fifth's Army frontin the winter of 1944, the ratioof trench foot to battle casualties was one to three and a half. These feet illustratethe ischemic phase of trench foot. The peripheral vessels are constricted. Oxygen deficiency in the capillaries leads to increase permeability, exudation,and edema. Tight clothing, direct injury to the skin due to cold, and traumafrom walking on damaged feet, probably accentuated the mechanism. When the affected feetwere exposed to warmth, the hyperemic phase developed. The vessels in these feet are dilated. Excessive vasodilatation is not controlledbecause the nerves have been injured. There's absorption of catabolitesfrom tissues damaged by cold or indirectlyby prolonged vasoconstriction. Permanently damaged capillaries allow extensive outpouring of plasmainto tissue interspaces. The pressure of this interstitial fluidon nerves gives pain, paresthesia, anesthesia,and sudomotor disturbances. Numbness of the feetand clumsiness in walking are the most prominent symptomsof trench foot during onset. Many men do not realizethat anything is wrong until they remove shoes and socks. Such was the history of this case, a foot soldier stationed above [?] Italy. Clinical manifestations are variable, but a mild case like thisis commonly characterized by erythema, slight sensory changes, and little or no pitting edema. It was a monthbefore this man returned to active duty. Trench foot can put a man out of actionas effectively as a bullet wound and may disable himfor a much longer time, occasionally forever. A moderate case showsthe same manifestations as a mild one, plus blebs, discoloration,and pitting edema. This case shows typical clinical signsof trench foot during the hyperemic phase. Feet become red, dry, and hot. Peripheral pulses, full and bounding. Initial anesthesia and hyperesthesia are replaced by an intense burning painover the surface of the entire foot, relieved by cold and aggravated by heat. As healing progresses,pain subsides and recedes distally. Edema usually reaches its heightby the fifth day and gradually recedesfollowed by a fine wrinkling of the skin. The red color slowly fades and may turn into a waxy pallorat about 10 days. For injuries not too grave, normal skin color returnsafter some exfoliation. In a cross-section of skin at this stage, we note superficial scaling, disappearance of rete pegs,and skin appendages, and increased and partly [?]collagen of the corium. In a severe trench foot condition, we seeall previously mentioned manifestations more pronounced, with evidenceof massive extravasations of blood and incipient or actual gangrene. These are the feet of a sergeant, also hospitalized from the Italian frontand eventually evacuated to the State. A well-marked line of demarcationdeveloped in time, and at Walter Reed General Hospitalfive months after leaving the front lines, this articulation of the toeswas accomplished without incident. The patient is sent to the hospitalas a litter case as soon as symptoms appear. His body kept warm by blankets, and his involved extremitiesexposed to cool air with only a loose clean covering over themfor aseptic purposes. The injured parts are handledas gently as possible. In the early stages,they must not be rubbed or massaged. They may be washed carefullywith mild white soap and water and dried. Affected parts are protectedagainst pressure necrosis, particularly at the heel. They are maintained at a horizontal level and elevated to slightly above heart level only if there is no evidenceof inadequate circulation indicating incipient gangrene. In the early ischemic stage when spasm of vessels is evidentand persists for longer than six hours, 1-ounce doses of whiskey may be givenfor its vasodilating effect. For the same purpose, sympathetic blocksusing 1% procaine hydrochloride solution may be used. Both block and whiskey are not indicatedafter the hyperemic stage begins and should be discontinued. Maintenance of minimal tissuemetabolism in the affected parts is especiallyimportant during the hyperemic phase. Where the room temperatureis not above 70°F, simple exposure of the partsmay be sufficient. If not, increased coolingis accomplished with a fan. Cooling could be still further increasedby spraying cold water through the fan. Measures to prevent secondary infection, including administrationof tetanus toxoid, are always instituted. Strict asepsismust be observed constantly. Sulfadiazine by mouth is usedin cases with threatened infections. Ordinarily, blisters are not disturbed. If opening becomes necessary,it is done aseptically. Heavy dressingsand all antiseptic solutions are avoided. Areas of necrosis and ulceration,which may develop, are treated conservatively. In cases of gangrene, amputation is delayed as long as possible and is done early only in the presenceof superimposed infections. A nutritious diet should be supplied,one high in proteins and vitamins. Physical therapy including diathermy, warm baths, exercises, and massage is of value in the late stagesand should be used. Sympathectomy is indicated only in cases showing objective evidenceof circulatory insufficiency, or in which manifestationsresembling Raynaud's phenomenon develop and persist months or yearsafter the acute phase of the disease and can be shown to be relievedby test sympathetic blocks. In milder trench foot cases,recovery is apparently complete. In more severe cases, sequelae have been observedfor months or years after exposure. There may be recurrenceof pain, tingling, and swelling, especially on walking,or prolonged standing, or exposure to cold. In some cases, deep-seated aching pain persists and may be associatedwith tenderness in the joints, usually worse at night. In others, there may belimitation of motion in the joints, muscle weakness,and difficulty in walking. Some cases complainof excessive perspiration of the feet. Anesthesia and paresthesiain the tips of the toes are not uncommon. The leg pains, the paresthesia,and rigidity of the parts may be due to compression of nerve endings and infiltration of muscle bundleswith scar tissue. In this tissue section, for example, we see much fibrosisand some atrophy of muscle fiber. In this one, the nerve,still somewhat [?], is being pressed upon by increased fibrous tissuessurrounding it. When such preventive measuresare followed, if in caseswhere trench foot has already developed, further injury is avoidedby proper first aid, and if infection and added fibrosis from carelessor ill-advised preliminary treatment are prevented or reduced. If all these things are done,needless casualties can be avoided. The greatest of these ifs is prevention. The time to eliminate trench footis before it happens. Unit commanders should be cognizantof trench foot factors and back medical disciplinewith military discipline in the prevention and cureof this important injury. Trench foot causes can be minimized,and its effects can be reduced. It takes intelligent cooperation among medical staff, combat units,and each individual fighting man. This is medicine in action. [music]