Use of fibrin-based thromboelastometry for cryoprecipitate transfusion in cardiac surgery involving deep hypothermic circulatory arrest during cardiopulmonary bypass

Abstract

We aimed to assess the predictive value of fibrin-based thromboelastometry performed before weaning from cardiopulmonary bypass (CPB) for cryoprecipitate administered to correct the bleeding diathesis after CPB involving deep hypothermic circulatory arrest. Eleven patients undergoing aortic surgery were enrolled. The arterial blood was withdrawn before skin incision, 30 min before CPB weaning (C_weaning), 5 min after protamine reversal (P_reversal) and at closure of the sternum to run intrinsically activated INTEM, heparinase-treated HEPTEM, extrinsically activated EXTEM and platelet-inhibited FIBTEM analysis, platelet count, fibrinogen, prothrombin time (international normalized ratio) and activated partial thromboplastin time. The predicted value of FIBTEM A10 obtained during CPB for cryoprecipitate transfusion at P_reversal was calculated. The cut-off points for FIBTEM A10 to reflect fibrinogen of 200 mg/dl at P_reversal were 5 mm (P = 0.15). FIBTEM A10 at P_reversal and C_weaning showed correlations as follows: FIBTEM A10 at P_reversal = 0.02 + 1.42 × FIBTEM A10 at C_weaning (r² = 0.80). The cut-off value for FIBTEM A10 at C_weaning to determine whether to prepare cryoprecipitate in advance during CPB was calculated to be 3 mm, and the positive and negative predictability for FIBTEM A10 of 3 or less versus more than 3 at C_weaning for the necessity of cryoprecipitate transfusion at P_reversal (A10 ≤ 5 versus > 5) were 100 and 80%, respectively. This study showed that fibrinogen reflected in FIBTEM during pump can be used to estimate FIBTEM after P_reversal and the amount of cryoprecipitate needed for replacing mainly the fibrinogen could be predicted with high sensitivity and specificity.