The management of patients on chronic Coumadin therapy undergoing subsequent surgical procedures

Coumadin, a long-acting antagonist of Vitamin K-dependent clotting factors, is commonly used for prevention of thromboembolism and potentially lethal clotting of mechanical heart valves. When patients require surgery for subsequent problems, inadequate perioperative management of coagulation may result in hemorrhage or thrombosis. Reversal with Vitamin K makes subsequent anticoagulation therapy difficult, and normalization 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, and 14 did not. In these two groups, sex, current operation, reason for anticoagulation, other drugs, admitting CBC, and platelet count were similar. Preoperative hospital days averaged 5.2 days in both groups. Statistically significant differences were noted in age, preoperative Coumadin dose, admitting prothrombin times, and postoperative stays (P = 0.05). Although the perioperative prothrombin times, partial thromboplastin times, and perioperative heparin doses were similar, more patients in the bleeding group were operated with a prothrombin time > 13.0 seconds. The current evolved protocol is to discontinue Coumadin 5 days before surgery, and begin intravenous heparin @ 1000 u/hr with adjustment to keep partial thromboplastin times at therapeutic levels. Heparin is stopped early on the morning of surgery and restarted at 200-400 units/hr at 4 to 6 hours after surgery. Coumadin is restarted as soon as the patient can tolerate it. It is considered safe to operate only when the prothrombin time is less than 13 seconds.(ABSTRACT TRUNCATED AT 250 WORDS)