Antifibrinolytic therapy with tranexamic acid in cardiac operations

To demonstrate its antifibrinolytic effects and establish an effective regi men of tranexamic acid for hemostasis, the authors measured alpha 2-plasmin inhibitor-plasmin complexes, thrombin-antithrombin III complexes and posto perative blood loss in three groups undergoing different regimens during ca rdiac operations. Forty-six patients undergoing coronary artery bypass graf ting or valve replacement were enrolled in this study. They were divided in to three groups of drug administration. A bolus infusion of 50 mg/kg tranex amic acid was given to 17 patients at the end of cardiopulmonary bypass (co ntrol group) and to 14 patients at the beginning of cardiopulmonary bypass (group A). In addition to the same bolus infusion at the beginning of cardi opulmonary bypass as group A, a continuous infusion of 10 mg/kg per h, star ting at the time of skin incision and maintained for 6 h after cardiopulmon ary bypass was given to 15 patients (group B). The marked increase in alpha 2-plasmin inhibitor-plasmin complexes at the end of cardiopulmonary bypass in the control group was significantly reduced in group A (P < 0.01) and a further reduction was observed in group B (P < 0.001). The difference in p ostoperative blood loss only reached significant levels between the control group and group B (P < 0.05). Although a significant increase in thrombin- antithrombin III complexes during cardiopulmonary bypass was similarly obse rved in all groups, no thromboembolic events occurred in any group, nor was any difference seen in graft patency. From the tranexamic acid therapy reg imens tested in this study, a continuous infusion of 10 mg/kg per h startin g at the time of skin incision to 6 h after cardiopulmonary bypass, with a bolus infusion of SO mg/kg at the beginning of cardiopulmonary bypass, prov ed to be the most effective. (C) 1999 The International Society for Cardiov ascular Surgery. Published by Elsevier Science Ltd. Ail rights reserved.