Effect of antithrombin in fresh frozen plasma on hemostasis after cardiopulmonary bypass surgery

Abstract

Introduction: Supplementation of fresh frozen plasma immediately after cardiopulmonary bypass is an effective method to enhance clotting ability as coagulation factors are consumed in the extracorporeal circuit during cardiopulmonary bypass. On the other hand, the anticoagulation factors in fresh frozen plasma can also deter the clotting ability. This study investigated the effect of fresh frozen plasma administration on the comprehensive clotting ability following cardiopulmonary bypass. Methods: This prospective observational study included 22 patients scheduled for cardiac surgery. Clotting times and maximum clot firmness were evaluated using the types of rotational thromboelastometry, intrinsic rotational thromboelastometry, and heparinase thromboelastography preoperatively, immediately after cardiopulmonary bypass, and 1 hour after cardiopulmonary bypass. Activated clotting time, antithrombin activity, and heparin concentration were also measured at these time-points. Results: Antithrombin activity (62.9 ± 7.2% vs. 51.1 ± 7.4%, p < 0.0001) and activated clotting time (132.6 ± 9.6% vs. 120.0 ± 9.0%, p < 0.001) were significantly higher 1 hour after cardiopulmonary bypass compared to measurements taken immediately after cardiopulmonary bypass. Heparin concentration 1 hour after cardiopulmonary bypass was significantly decreased compared to that immediately after cardiopulmonary bypass. On the other hand, maximum clot firmness determined via intrinsic rotational thromboelastometry was significantly greater 1 hour after cardiopulmonary bypass (53.8 ± 4.8 mm) than that immediately after cardiopulmonary bypass (49.5 ± 4.8 mm). Clotting time determined via intrinsic rotational thromboelastometry and heparinase thromboelastography was also significantly shorter 1 hour after cardiopulmonary bypass than that immediately after cardiopulmonary bypass. Conclusion: Fresh frozen plasma administration increased antithrombin activity and caused activated clotting time prolongation, but then increased clotting ability. Thus, testing by rotational thromboelastometry after cardiopulmonary bypass could be valuable in the detection of comprehensive clotting ability.