HEPARIN-PROTAMINE MISMATCH - A CONTROLLABLE FACTOR IN BLEEDING AFTER OPEN-HEART-SURGERY

Objective: To test the effect of a new system designed to reduce hepar in-protamine mismatch on bleeding after open heart surgery. Design: No nrandomized but consecutive retrospective review of patients undergoin g open heart surgery during a 9-month period. Setting: Multispecialty referral center. Patients: A total of 150 patients comparable by age, body surface area, and coagulation status undergoing primary open hear t surgery for either coronary bypass or heart valve replacement. Inter vention: In the first 75 patients (group 1), heparin sodium was neutra lized with protamine sulfate, using a fixed ratio (1 mg of heparin sod ium to 1.3 mg of protamine sulfate). An activated clotting time was us ed to confirm heparin neutralization. For the subsequent 75 patients ( group 2), titration of heparin and protamine from defined lots was acc omplished using activated dotting times adjusted and matched to drug l ots to minimize biologic variability. Groups 1 and 2 had comparable op erations, pump times, and cross-clamp times. Main Outcome Measures: Do ses of heparin and protamine and their effect on blood product transfu sion and postoperative bleeding were evaluated in all patients. Result s: The average protamine sulfate dose for group 2 patients (287.56+/-8 .3 mg) was significantly lower than that for group 1 (346.01+/-12.6 mg ) (P<.0005). Less protamine was associated with the transfusion of few er red blood cells (0.92+/-0.15 vs 2.57+/-0.38 U) (P<.001), platelets (0.72+/-0.8 vs 2.96+/-0.80 U) (P<.01), and fresh-frozen plama (0.83+/- 2.0 vs 2.01+/-0.48 U) (P<.03). No patients in group 2 required reexplo ration for bleeding, compared with eight patients in group 1. Conclusi ons: A reduction in protamine dose was associated with significant dec reases in blood product use and postoperative bleeding. Excess protami ne warrants consideration as both an important and a controllable fact or in coagulopathy after open heart surgery.