Postoperatively administered aprotinin or epsilon aminocaproic acid after cardiopulmonary bypass has limited benefit

Background. Intraoperative antifibrinolytic treatment with aprotinin and epsilon aminocaproic acid (EACA) has been shown to be effective prophylaxis in the reduction of excessive bleeding after cardiopulmonary bypass operations. This study investigated the effectiveness of both drugs when used as a postoperative treatment of patients showing early signs of increased bleeding. Methods. In a double-blind, randomized study, 69 patients with chest drainage of 100 mL or more 1 hour after bypass were treated with aprotinin, EACA, or placebo. Results. In the first 24 hours postoperatively, neither drug significantly reduced chest drainage or blood transfusion requirements compared with placebo. Median (interquartile) cumulative chest drainage volumes for the first 24 hours postoperatively for the aprotinin, EACA, and placebo groups were 525 (340, 750), 575 (450, 762), and 650 (550, 800) mL, respectively. Among the study patients, 4 undergoing valve operation and treated with aprotinin showed a trend toward less bleeding during the first 12 hours postoperatively compared with 5 valve operation patients who received placebo (p = 0.06). Among all patients, the treatment with aprotinin or EACA failed to reduce levels of D-dimer compared with placebo after treatment, indicating that fibrinolysis was not significantly inhibited. Conclusions. Aprotinin or EACA administered in the early postoperative period was ineffective in reducing postoperative bleeding with the exception of a small group of patients having valve operations in whom aprotinin treatment may have shown some benefit.