Effect of tranexamic acid on blood loss reduction after cardiopulmonary bypass.

Objective: We evaluated the effect of tranexamic acid on blood loss in patients undergoing elective cardiopulmonary bypass for coronary artery bypass surgery.Methods: We randomly assigned 7 of 14 patients to a group receiving 50 mg/kg tranexamic acid before skin incision and after the start of cardiopulmonary bypass and the other 7 as controls.Results: Intraoperative and postoperative blood loss was significantly (p=0.025) reduced in the tranexamic acid group. A similar decrease in platelet count was observed during cardiopulmonary bypass in both groups. Antithrombin III was significantly (p=0.013) decreased in both groups during cardiopulmonary bypass. Antithrombin III and thrombin- antithrombin III complexes were signficantly (p=0.001) increased after protamine administration. A significant (p=0.010) decrease in α2-plasmin inhibitor was noted at 5 and 60 minutes after the start of cardiopulmonary bypass in the tranexamic acid group. α2-plasmin inhibitor-plasmin complexes were significantly (p=0.001) increased after the start of cardiopulmonary bypass in both groups and were significantly (p=0.012) decreased after protamine administration α2-plasmin inhibitor-plasmin complexes in the tranexamic acid group were significantly (p=0.030) lower than in controls 60 minutes after the start of cardiopulmonary bypass, just prior to the end of cardiopulmonary bypass, and after protamine administration.Conclusion: These findings showed that tranexamic acid administration effectively prevented perioperative blood loss without thromboembolic complications and that tranexamic acid during cardiopulmonary bypass coordinates the anticoagulative effect of heparin and the antifibrinolytic effect of tranexamic acid.