THE MANAGEMENT OF PATIENTS ON CHRONIC COUMADIN THERAPY UNDERGOING SUBSEQUENT SURGICAL-PROCEDURES

Coumadin, a long-acting antagonist of Vitamin K-dependent clotting fac tors, is commonly used for prevention of thromboembolism and potential ly lethal clotting of mechanical heart valves. When patients require s urgery for subsequent problems, inadequate perioperative management of coagulation may result in hemorrhage or thrombosis. Reversal with Vit amin K makes subsequent anticoagulation therapy difficult, and normali zation of coagulation with fresh frozen plasma exposes the patient to the risk of fatal valvular thrombosis. In addition, third party payers and governmental reimbursement policies discourage most, if not all, preoperative hospitalization. Twenty-one patients on chronic Coumadin therapy required surgery for diseases unrelated to their original need for anticoagulation. Seven patients had hemorrhagic complications, an d 14 did not. In these two groups, sex, current operation, reason for anticoagulation, other drugs, admitting CBC, and platelet count were s imilar. Preoperative hospital days averaged 5.2 days in both groups. S tatistically significant differences were noted in age, preoperative C oumadin dose, admitting prothrombin times, and postoperative stays (P = 0.05). Although the perioperative prothrombin times, partial thrombo plastin times, and perioperative heparin doses were similar, more pati ents in the bleeding group were operated with a prothrombin time >13.0 seconds. The current evolved protocol is to discontinue Coumadin 5 da ys before surgery, and begin intravenous heparin @ 1000 u/hr with adju stment to keep partial thromboplastin times at therapeutic levels. Hep arin is stopped early on the morning of surgery and restarted at 200-4 00 units/hr at 4 to 6 hours after surgery. Coumadin is restarted as so on as the patient can tolerate it. It is considered safe to operate on ly when the prothrombin time is less than 13 seconds. Seven patients h ad bleeding complications requiring reoperation and prolonged hospital ization, but no patient had any thromboembolic complication, and no pa tients died. The differences in age, Coumadin dose, and admitting PT s uggest that younger patients are treated more aggressively with antico agulants, and perhaps that these individuals should have their Coumadi n stopped earlier than older patients on less Coumadin. Utilizing the described protocol, the risk of more perioperative bleeding is accepte d to avoid the more lethal problems associated with valvular thrombosi s and embolization.