Pennsylvania Patient Safety Advisory Epidural or Subarachnoid Catheter Shear ABSTRACT to remove the distal portion. Neurosurgery was Epidural or subarachnoid catheters (sometimes called consulted on whether or not to remove the severed lumbar drainage catheters) are very small hollow catheter via laminectomy. tubes inserted into the epidural or subarachnoid space to administer medications or drain body fluids, A catheter insertion was attempted in the preopera- respectively. Under certain conditions they can shear, tive PACU [postanesthesia care unit]. . . While the leaving a fragment in the patient. Between June 2004 catheter placement was checked by pulling back on and December 2008, the Pennsylvania Patient Safety the catheter, the catheter tip sheared off. A CT [com- Authority received 13 reports related to epidural or puted tomography] scan confirmed that there was a subarachnoid catheter shear. However, most catheter piece of catheter present in the paraspinal muscula- procedures occur without complications. The predomi- ture at the level of a lumbar facet. It is posterior to nant causes of catheter shear are applying excessive the spinal canal. No catheter fragments were identi- force while removing the catheter, withdrawing the fied in the spinal canal. catheter back through the needle, withdrawing the Reasons for Catheter Shear catheter over a deformed or damaged needle bevel, or damaging the catheter during or after placement An epidural or subarachnoid catheter* is a very small in the patient. Defects in the catheter occuring dur- flexible hollow tube that can be inserted into epidural ing the manufacturing process can also be a cause space to administer fluids (e.g., pain medication) or of catheter shear. The position of the patient during into the subarachnoid space to drain body fluids (e.g., insertion and withdrawal of the catheter can play an cerebral spinal fluid). On occasion, spinal catheters important part in reducing the likelihood of fracturing are placed in the subarachnoid space to administer the catheter. For difficult-to-remove catheters, allowing medications as well. Depending on a patient’s medi- the patient’s back muscles to relax for a few days may cal condition, a catheter may be placed on a short- or facilitate the removal in some cases. Unless complica- long-term basis. Under certain circumstances, cath- tions arise, surgery is unnecessary in most cases since eters can break. The majority of catheter procedures catheters are constructed from inert materials. occur without complications; however, catheters have (Pa Patient Saf Advis 2009 Sep;6[3]:84-6.) been sheared in some cases.1 Shearing typically occurs during insertion or removal of the catheter from patients.1 Catheter fragments remaining in patients can result in serious complications due to the location At the request of a Patient Safety Officer at a or migration of the fragment or inflammation at the Pennsylvania healthcare facility, Pennsylvania Patient fragment site.1 Reasons for catheter shearing include Safety Authority analysts examined events of sheared the following:† spinal and epidural catheters reported between June ■ Applying excessive force while removing the 2004 and December 2008. During that time, 13 events catheter were reported to the Authority relevant to spinal and epidural catheter shear, which corroborate reports ■ Withdrawing the catheter back through the inser- in current literature. The following are examples of tion needle reports of spinal and epidural catheter shear submit- ■ Withdrawing the catheter over a deformed or dam- ted to the Authority: aged needle bevel A lumbar puncture was attempted to rule out men- ■ A flaw in the catheter from defects during the ingitis. Noted 1.5 mm puncture or possible sheared manufacturing process area on soft catheter withdrawn from vertebral ■Damaging the catheter during or after placement space. Apparently, reentering the trocar into the soft in the patient catheter while attempting entry in the cerebrospinal column punctured/sheared the catheter. Applying Excessive Force A user may use excessive force if he or she encoun- While doing a lumbar drain, the moulding portion ters resistance during catheter removal. Patient of the [brand omitted] lumbar drain was sheared off. position during insertion or removal of the catheter According to the physician, it could not be retrieved may increase the resistance. For example, excessive as it is not radiopaque. The anesthesiologist inserted a spinal drain to main- * For the remainder of this discussion, the term “catheter” will be used tain cerebrospinal pressure at <10 mm Hg. The with the understanding that the discussion pertains to epidural and subarachnoid catheters. catheter was placed at the lumbar area without † This list and the accompanying discussion represent some causes of trauma. The patient moved during removal of the catheter shear based on documented evidence, but neither the list nor needle introducer, severing the catheter. . . . Unable discussion is comprehensive. Page 84 REPRINTED ARTICLE - ©2009 Pennsylvania Patient Safety Authority Vol. 6, No. 3—September 2009 Pennsylvania Patient Safety Advisory force might be applied if the catheter is placed while Avoiding Catheter Shear during Removal the patient’s back is arched but is removed with When encountering a catheter that is difficult to the patient in a different position (e.g., sitting posi- remove, the following methods are available to clini- tion).2 Boey et al. observed that the force required to cians to reduce the risk of catheter shear:1 remove an epidural catheter was 2.5 times more with ■ Place the patient in a position that will exert the a patient in the sitting position than in the lateral least amount of pressure during insertion and with- decubitus position.3 Morris et al. recommend that the drawal of the catheter, such as the lateral decubitus patient be placed in the same position for insertion position. and withdrawal of the catheter.4 ■ To help identify any knots or entanglements, Withdrawing through the Insertion Needle consider injecting sterile saline into the catheter. If a knot is encountered, gentle, firm traction may A very sharp needle bevel may shear the catheter with tighten the knot, making it smaller. Decreasing the minimal retraction or manipulation of the catheter size of the knot may ease catheter removal. during insertion. According to Olivar et al., when dif- ■ Do not use metal forceps, hemostats, or clamps to ficulty in advancing the catheter is encountered, users remove catheters; their use may increase the likeli- tend to partially withdraw (back through the needle) hood of fracturing the catheter. then reinsert the catheter.2 The authors suggest that ■ Allow the patient’s back muscles to relax for a few the catheter never be withdrawn from the needle days to facilitate catheter removal. once the catheter tip has passed through the needle;2 rather, the needle and catheter should be withdrawn ■ If pain or paresthesia develops during catheter as a unit, or the needle should be withdrawn first. removal in the intrathecal space, stop removal and consider performing a neurosurgical consultation Withdrawing the Catheter over a Deformed or with radiographic evaluation to help in determin- Damaged Needle Bevel ing the location of the retained catheter. ■ Consider surgical removal of the catheter for Catheters may shear from snagging on imperfections patients who are symptomatic. Unless complica- such as barbs or nicks on the bevel of an unsharpened tions develop, surgery may be unwarranted since needle.1 the catheter is inert. Manufacturing Defects Notes 1. Fischer R. Epidural conduction device fractures and Catheter fractures are rarely related to manufacturing complications of retained fragments. AANA J 2008 defects.5 However, defects such as a bubble or foreign Feb;76(1):37-40. material in the catheter wall can cause the catheter to 2. Olivar H, Bramhall J, Rozet I, et al. Subarachnoid lum- break under less force than that required to break an bar drains: a case series of fractured catheters and a near intact catheter (i.e., without a defect).5 miss. Can J Anesth 2007 Oct;54(10):829-34. Damaging the Catheter during or after Placement 3. Boey S, Carrie LE. Withdrawal forces during removal of lumbar extradural catheters. Br J Anaesth 1994 Dec; Manipulating the catheter within the patient can 73(6):833-5. cause the catheter to become trapped.1 A catheter 4. Morris GN, Warren BB, Hanson EW, et al. Influence can become looped or knotted from curling back of patient position on withdrawal forces during removal on itself when deflected by anatomical structures.1 of lumbar extradural catheters. Br J Anaesth 1996 Sep; Epidural catheters can also become entrapped in 77(3):419-20. nerve roots, blood vessels, lumbar fascia, posterior 5. ECRI Institute. Epidural catheter breakages [from the vertebral arches, and facet joints.1 The use of clamps accident investigation archives]. Risk Manag Reporter or hemostats to remove catheters can result in frac- 2009 Apr;28(2):19. tures. In a 2001 study, Nishio et al. observed that 6. Nishio I, Sekiguchi M, Aoyama Y, et al. Decreased the tensile strength of catheters decreased with the tensile strength of an epidural catheter during its use of a stainless steel hemostat at the site grasped by removal by grasping with a hemostat. Anesth Analg 2001 the hemostat.6 Jul;93(1):210-2. (See Self-Assessment Questions on next page.) Vol. 6, No. 3—September 2009 REPRINTED ARTICLE - ©2009 Pennsylvania Patient Safety Authority Page 85 ? Pennsylvania Patient Safety Advisory ? Self-Assessment Questions The following questions about this article may be useful for internal education and assessment. You may use the following 4. A patient experiences pain and paresthesia during catheter removal in the intrathecal space. examples or come up with your own. Select what to do when encountering this situation. 1. Which of the following factors is NOT a reason for a. Allow the patient’s back muscles to relax for a few days catheter shear? to facilitate catheter removal. a. Application of excessive force while removing the b. Stop the removal and consider performing a neurosur- catheter gical consultation with radiographic evaluation to help b. Withdrawal of the catheter back through the insertion in determining the location of the retained catheter. needle c. Apply firm, steady traction when removing the c. A flaw in the catheter caused by defects during the retained catheter. manufacturing process d. Pull sharply on the retained catheter to facilitate d. Placement of the patient in the lateral decubitus posi- withdrawal. tion during insertion and withdrawal of the catheter 5. An obstetric patient underwent epidural anesthesia e. Withdrawal of the catheter over a deformed or dam- during labor. During removal, the catheter began to aged needle bevel stretch. Injection of saline through the catheter showed 2. All of the following are methods for avoiding catheter that the catheter was obstructed, most likely due to a knot. shear EXCEPT: Select the appropriate method to remove the knotted a. Using metal forceps, hemostats, or clamps to remove catheter. catheters a. Pull on the catheter with gentle, firm traction to b. Allowing the patient’s back muscles to relax for a few reduce the size of the knot. days to facilitate catheter removal b. Surgically remove the catheter. c. Injecting saline into the catheter to help identify any c. Place the patient in the sitting position. knots or entanglements d. Grasp the catheter with forceps and pull sharply to d. Surgically removing the catheter from patients who are remove the catheter. symptomatic 3. The following methods are likely to minimize resistance during withdrawal of the catheter EXCEPT: a. Placing the patient in the lateral decubitus position b. Placing the patient in the sitting position c. Placing the patient in the same position for insertion and withdrawal of the catheter d. Allowing the patient’s back muscles to relax for a few days Page 86 REPRINTED ARTICLE - ©2009 Pennsylvania Patient Safety Authority Vol. 6, No. 3—September 2009 PENNSYLVANIA PATIENT SAFETY ADVISORY This article is reprinted from the Pennsylvania Patient Safety Advisory, Vol. 6, No. 3—September 2009. The Advisory is a publication of the Pennsylvania Patient Safety Authority, produced by ECRI Institute and ISMP under contract to the Authority. Copyright 2009 by the Pennsylvania Patient Safety Authority. This publication may be reprinted and distributed without restriction, provided it is printed or distributed in its entirety and without alteration. Individual articles may be reprinted in their entirety and without alteration provided the source is clearly attributed. This publication is disseminated via e-mail. To subscribe, go to https://www.papsrs.state.pa.us/ Workflow/MailingListAddition.aspx. To see other articles or issues of the Advisory, visit our Web site at http://www.patientsafetyauthority.org. Click on “Patient Safety Advisories” in the left-hand menu bar. THE PENNSYLVANIA PATIENT SAFETY AUTHORITY AND ITS CONTRACTORS The Pennsylvania Patient Safety Authority is an independent state agency created by Act 13 of 2002, the Medical Care Availability and Reduction of Error (“Mcare”) Act. Consistent with Act 13, ECRI Institute, as contractor for the Authority, is issuing this publication to advise medical facilities of immediate changes that can be instituted to reduce Serious Events and Incidents. For more information about the Pennsylvania Patient Safety Authority, see the Authority’s Web An Independent Agency of the Commonwealth of Pennsylvania site at http://www.patientsafetyauthority.org. ECRI Institute, a nonprofit organization, dedicates itself to bringing the discipline of applied scientific research in healthcare to uncover the best approaches to improving patient care. As pioneers in this science for nearly 40 years, ECRI Institute marries experience and independence with the objectivity of evidence-based research. More than 5,000 healthcare organizations worldwide rely on ECRI Institute’s expertise in patient safety improvement, risk and quality management, and healthcare processes, devices, procedures and drug technology. The Institute for Safe Medication Practices (ISMP) is an independent, nonprofit organization dedicated solely to medication error prevention and safe medication use. ISMP provides recommendations for the safe use of medications to the healthcare community including healthcare professionals, government agencies, accrediting organizations, and consumers. ISMP’s efforts are built on a nonpunitive approach and systems-based solutions.