- Email: [email protected]
Response to Dr. Kaplan
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Regional Anesthesia and Pain Medicine Vol. 24 No. 5 September-October 1999
stopped for its k n o w n duration of neural block, 10 mL of a 1:100,000 solution of epinephrine in saline were injected, the catheter was slowly removed over approximately 20-30 seconds, and the patients were monitored for possible neurologic sequelae. As noted by the consensus conference, "We can make no definitive recommendation for removal of neuraxial catheters in patients with therapeutic levels of anticoagulation during neuraxial catheter infusion. Clinical judgment must be exercised in making decisions about removing or maintaining these catheters" (15). Although these two experiences cannot establish the described approach as a "definitive recommendation" for clinical practice, clinical judgment should include the knowledge of the effects of epinephrine, local anesthetic agents, and neuraxial block on coagulation. The consensus statements "are subject to timely revision, as justified by evolution of information and practice" ( 11 ). Future revisions by the consensus committee should at least address the use of epinephrine and the timing of local anesthetic administration relative to catheter withdrawal. It seems only logical based on their k n o w n pharmacology and physiology relating to hemostasis.
9. Bredbacka S, Blomb~ickM, Hfignevik K, Irestedt L, Raabe N. Pre- and postoperative changes in coagulation and fibrinolyric variables during abdominal hysterectomy under epidural or general anesthesia. Acta Anaesthesiol Scand 1986: 30: 204--210. 10. Aken HV, Miller ED. Deliberate hypotension. In: Miller RD, (ed). Anesthesia, 4th ed. New York, Churchill Livingstone, 1994: 1481-1503. 11. Horlocker TT, Wedel DJ. Anticoagulation and neuraxial block: Historical perspective, anesthetic implications, and risk management. Reg Anesth Pain Med 1998: 23(6) Suppl 2: 129-134. 12. Heit JA. Low-molecular weight heparin: Biochemistry, pharmacology, and concurrent drug precautions. Reg Anesth Pain Med 1998: 23(6) Suppl 2: 135-139. 13. Schroeder DR. Statistics: Detecting a rare adverse drug reaction using spontaneous reports. Reg Anesth Fain Med 1998: 23(6) Suppl 2: 183-18% 14. Landow L. Monitoring adverse drug events: The Food and Drug Administration MedWatch reporting system. Reg Anesth Pain Med 1998: 23(6) Suppl 2: 190-193. 15. Enneking FK, Benzon H. Oral anticoagulants and regional anesthesia: A perspective. Reg Anesth Pain Med 1998: 23(6) Suppl 2: 140-145.
Accepted for publication March 12, 1999.
Ronald Kaplan, M.D.
Albert Einstein Collegeof Medicine Montefiore Medical Center Bronx, New York
References 1. American Society of Regional Anesthesia Consensus Conference. Neuraxial Anesthesia and Anticoagulation. Consensus Statements. American Society of Regional Anesthesia, p.o. Box 11086, Richmond, VA 23230-1086. 2. Reg Anesth Pain Med 1998: 23: 129-194, Suppl 2. 3. Hoffman BB, Lefkowitz RJ. Catecholamines, sympathomimetic drugs, and adrenergic receptor antagonists. In: Hardman JG, Limird LE, eds. The Pharmacologic Basis of Therapeutics. Section II: Drugs Acting at Synaptic and Neuroeffector Junctional Sites. New York, McGraw-Hill, 1996: 199-248. 4. Handin RI. Bleeding and thrombosis. In: Wilson JD, Braunwald E, Isselbacher KJ, et al., (eds). Harrison's Principles of Internal Medicine. Volume 1, Part Two: Cardinal Manifestations of Disease. New York, McGraw-Hill, 1991: 348353. 5. Rosenfeld BA. Benefits of regional anesthesia on thromboembolic complications following surgery. Reg Anesth 1996: 21(6S): 9-12. 6. Liu S, Carpenter RL, Neal JM. Epidural anesthesia and analgesia. Their role in postoperative outcome. Review article. Anesthesiology 1995: 82: 1474-1506. 7. Christopherson R, Beattie C, Frank SM, Norris EJ, Meinert CL, Gottlieb SO, Yates H, Rock P, Parker SD, Perler BA, Williams GM. Perioperative ischemia randomized anesthesia trial study group: Perioperative morbidity in patients randomized to epidural or general anesthesia for lower extremity vascular surgery. Anesthesiology 1993: 79: 422434. 8. Rosenfeld BA, Beattie C, Christopherson R, Norris EJ, Frank SM, Breslow MJ, Rock P, Parker SD, Gottlieb SO, Pefler BA, Williams GM, Seidler A, Bell W. Perioperative ischemia randomized anesthesia trial study group: The effects of different anesthetic regimens on fibrinolysis and the development of postoperative arterial thrombosis. Anesthesiology 1993: 79: 435-443.
Response to Dr. Kaplan To the Editor: Dr. Kaplan believes that an indwelling epidural catheter may be safely r em o v ed in the presence of systemic anticoagulation if the neural block is allowed to resolve and a small volume of 1:200,000 to 1:100,000 epinephrine is injected into the epidural space. His recommendation is based on several theoretical reasons and 2 patients w h o were managed with this technique. We strongly disagree that "these two experiences establish the described approach as a definitive recommendation for clinical practice." No current investigations suggest that epidurally administered epinephrine improves intravascular hemostasis or that local anesthetics induce a hypocoagulable state that should be reversed prior to catheter removal. Therefore, we continue to r e c o m m e n d efforts which minimize all anticoagulant and antithrombotic effects at the time of neuraxial catheter manipulation as the safest and most effective means of reducing the risk of spinal h e m a t o m a associated with neuraxial block. Terese T. Horlocker, M.D.
Department of Anesthesiology Division of Cardiovascular Diseases, Section of Vascular Medicine; and the Division of Hematology, Section of Hematology Research, Department of Medicine John A. Heit, M.D.
Mayo Clinic and Foundation Rochester, Minnesota Accepted for publication April 13, 1999.
Regional Anesthesia and Pain Medicine Vol. 24 No. 5 September-October 1999
stopped for its k n o w n duration of neural block, 10 mL of a 1:100,000 solution of epinephrine in saline were injected, the catheter was slowly removed over approximately 20-30 seconds, and the patients were monitored for possible neurologic sequelae. As noted by the consensus conference, "We can make no definitive recommendation for removal of neuraxial catheters in patients with therapeutic levels of anticoagulation during neuraxial catheter infusion. Clinical judgment must be exercised in making decisions about removing or maintaining these catheters" (15). Although these two experiences cannot establish the described approach as a "definitive recommendation" for clinical practice, clinical judgment should include the knowledge of the effects of epinephrine, local anesthetic agents, and neuraxial block on coagulation. The consensus statements "are subject to timely revision, as justified by evolution of information and practice" ( 11 ). Future revisions by the consensus committee should at least address the use of epinephrine and the timing of local anesthetic administration relative to catheter withdrawal. It seems only logical based on their k n o w n pharmacology and physiology relating to hemostasis.
9. Bredbacka S, Blomb~ickM, Hfignevik K, Irestedt L, Raabe N. Pre- and postoperative changes in coagulation and fibrinolyric variables during abdominal hysterectomy under epidural or general anesthesia. Acta Anaesthesiol Scand 1986: 30: 204--210. 10. Aken HV, Miller ED. Deliberate hypotension. In: Miller RD, (ed). Anesthesia, 4th ed. New York, Churchill Livingstone, 1994: 1481-1503. 11. Horlocker TT, Wedel DJ. Anticoagulation and neuraxial block: Historical perspective, anesthetic implications, and risk management. Reg Anesth Pain Med 1998: 23(6) Suppl 2: 129-134. 12. Heit JA. Low-molecular weight heparin: Biochemistry, pharmacology, and concurrent drug precautions. Reg Anesth Pain Med 1998: 23(6) Suppl 2: 135-139. 13. Schroeder DR. Statistics: Detecting a rare adverse drug reaction using spontaneous reports. Reg Anesth Fain Med 1998: 23(6) Suppl 2: 183-18% 14. Landow L. Monitoring adverse drug events: The Food and Drug Administration MedWatch reporting system. Reg Anesth Pain Med 1998: 23(6) Suppl 2: 190-193. 15. Enneking FK, Benzon H. Oral anticoagulants and regional anesthesia: A perspective. Reg Anesth Pain Med 1998: 23(6) Suppl 2: 140-145.
Accepted for publication March 12, 1999.
Ronald Kaplan, M.D.
Albert Einstein Collegeof Medicine Montefiore Medical Center Bronx, New York
References 1. American Society of Regional Anesthesia Consensus Conference. Neuraxial Anesthesia and Anticoagulation. Consensus Statements. American Society of Regional Anesthesia, p.o. Box 11086, Richmond, VA 23230-1086. 2. Reg Anesth Pain Med 1998: 23: 129-194, Suppl 2. 3. Hoffman BB, Lefkowitz RJ. Catecholamines, sympathomimetic drugs, and adrenergic receptor antagonists. In: Hardman JG, Limird LE, eds. The Pharmacologic Basis of Therapeutics. Section II: Drugs Acting at Synaptic and Neuroeffector Junctional Sites. New York, McGraw-Hill, 1996: 199-248. 4. Handin RI. Bleeding and thrombosis. In: Wilson JD, Braunwald E, Isselbacher KJ, et al., (eds). Harrison's Principles of Internal Medicine. Volume 1, Part Two: Cardinal Manifestations of Disease. New York, McGraw-Hill, 1991: 348353. 5. Rosenfeld BA. Benefits of regional anesthesia on thromboembolic complications following surgery. Reg Anesth 1996: 21(6S): 9-12. 6. Liu S, Carpenter RL, Neal JM. Epidural anesthesia and analgesia. Their role in postoperative outcome. Review article. Anesthesiology 1995: 82: 1474-1506. 7. Christopherson R, Beattie C, Frank SM, Norris EJ, Meinert CL, Gottlieb SO, Yates H, Rock P, Parker SD, Perler BA, Williams GM. Perioperative ischemia randomized anesthesia trial study group: Perioperative morbidity in patients randomized to epidural or general anesthesia for lower extremity vascular surgery. Anesthesiology 1993: 79: 422434. 8. Rosenfeld BA, Beattie C, Christopherson R, Norris EJ, Frank SM, Breslow MJ, Rock P, Parker SD, Gottlieb SO, Pefler BA, Williams GM, Seidler A, Bell W. Perioperative ischemia randomized anesthesia trial study group: The effects of different anesthetic regimens on fibrinolysis and the development of postoperative arterial thrombosis. Anesthesiology 1993: 79: 435-443.
Response to Dr. Kaplan To the Editor: Dr. Kaplan believes that an indwelling epidural catheter may be safely r em o v ed in the presence of systemic anticoagulation if the neural block is allowed to resolve and a small volume of 1:200,000 to 1:100,000 epinephrine is injected into the epidural space. His recommendation is based on several theoretical reasons and 2 patients w h o were managed with this technique. We strongly disagree that "these two experiences establish the described approach as a definitive recommendation for clinical practice." No current investigations suggest that epidurally administered epinephrine improves intravascular hemostasis or that local anesthetics induce a hypocoagulable state that should be reversed prior to catheter removal. Therefore, we continue to r e c o m m e n d efforts which minimize all anticoagulant and antithrombotic effects at the time of neuraxial catheter manipulation as the safest and most effective means of reducing the risk of spinal h e m a t o m a associated with neuraxial block. Terese T. Horlocker, M.D.
Department of Anesthesiology Division of Cardiovascular Diseases, Section of Vascular Medicine; and the Division of Hematology, Section of Hematology Research, Department of Medicine John A. Heit, M.D.
Mayo Clinic and Foundation Rochester, Minnesota Accepted for publication April 13, 1999.