ARE IN-VITRO PLATELET-FUNCTION TESTS USEFUL IN PREDICTING BLOOD-LOSS FOLLOWING OPEN-HEART-SURGERY

Background: We investigated the suitability of two commercially availa ble in-vitro bleeding tests (IVBT), the PFA-100(R) and the Hepcon(R) H MS, to predict blood loss following operations with extracorporeal cir culation (ECC) and compared them with conventional coagulation studies . Methods: In 40 patients subjected to elective open heart surgery wit h ECC a blood sample was taken before and after ECC to measure platele t count, prothrombin time, aPTT, D-dimers, fibrinogen, and PFA-100(R) and Hepcon(R) HMS data. The postoperative blood loss was recorded hour ly until removal of drains. Results: A significant correlation was fou nd between total blood loss (250-1750 ml) and the preoperative PFA-100 (R) (r = 0.41, p = 0.022), the preoperative platelet count (r = - 0.42 , p = 0.007), the preoperative D-dimer concentration in the plasma (r = 0.41, p = 0.01), and duration of ECC (r = 0.35, p = 0.044), There wa s no significant correlation between blood loss and the Hepcon(R) HMS system. Conclusions: Although a significant correlation was found betw een blood loss and the PFA-100 IVBT, the practical value of these test s in the clinical situation is limited due to a great variability in i ndividual results.