Are In-Vitro Platelet Function Tests Useful in Predicting Blood Loss Following Open Heart Surgery?

Abstract

Background: We investigated the suitability of two commercially available in-vitro bleeding tests (IVBT), the PFA-100^® and the Hepcon^® “ HMS, to predict blood loss following operations with extracorporeal circulation (ECC) and compared them with conventional coagulation studies. Methods: In 40 patients subjected to elective open heart surgery with ECC a blood sample was taken before and after ECC to measure platelet count, prothrombin time, aPTT, D-dimers, fibrinogen, and PFA-100^® and Hepcon^® “ HMS data. The postoperative blood loss was recorded hourly until removal of drains. Results: A significant correlation wasfound between total blood loss (250-1750 ml) and the preoperative PFA-100^® “ (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 was no significant correlation between blood loss and the Hepcon^® HMS system. Conclusions: Although a significant correlation was found between blood loss and the PFA-100 IVBT, the practical value of these tests in the clinical situation is limited due to a great variability in individual results.

Key words

Open heart surgery - Blood loss - Platelet function - In vitro bleeding test