Clinical significance of heparin in the residual pump oxygenator blood, reinfused postoperatively after cardiopulmonary bypass

Abstract

Postcardiopulmonary bypass (CPB) heparin levels and thrombin time were measured in 20 patients following routine open cardiac operations. There was a statistically significant increase in heparin concentration and thrombin time ratio on completion of transfusion of the residual pump oxygenator blood. An hour after the end of the transfusion there was no statistically significant difference in the heparin concentration and thrombin time ratio compared to values before and immediately after transfusion. We also observed a significant decrease in the chest drainage over a period of four hours which was unrelated to plasma heparin level. Measurements of thrombin time in the post bypass period closely follow plasma heparin levels. If postoperative bleeding arose it was due to inadequate surgical haemostasis or coagulation defect other than residual heparinization. Thus this confirms further that heparin is not the sole aetiological factor in postoperative bleeding post-CPB.