Effect of cardiopulmonary bypass on hemostatic mechanism in open heart surgery

ABSTRACT

The clinical significance of alteration in coagulation and fibrinolysis following CPB was studied in [20] cardiac patients undergoing elective open heart surgery for value replacement or repair. To all patients, the following tests were done Platelet count, platelet aggregation, bleeding time, prothrombin time, euglobulin clot lysis time, fibrin degradation products, plasma beta thromboglobulin and plasma platelet factor 4 in 4 predetermined time. The results of the study showed significant decrease of platelet count, platelet aggregation and euglobulin clot lysis time while bleeding time and prothrombin time were significantly increased 30 minutes after CPB and one hour postoperative [P< 0.05]. All the previous parameters slightly approached the pre-operative value 24 hours post-operative but did not reach it. 5 patients [25%] showed abnormal level of FDPs [>10 ug/ml]. Beta thromboglobulin and platelet factor 4 significantly increased 30 minutes after CPB [P< 0.05]. One hour postoperative, platelet factor 4 reached the pre-operative value while beta thromboglobulin reached the preoperative value 24 hours postoperative. A significant negative correlation was found between 24 hours blood loss and both platelet count [r= 0.7] and ECLT [r= 0.7] and P.T. [r= 0.8]. So it is concluded that platelet dysfunction is the most important cause of inadequate restoration of coagulation function after CPS