Effect of Cardiopulmonary Bypass Machine on the Platelet Function Testing.

Abstract

Background: Bleeding during coronary artery bypass surgery is a leading cause of mortality. Several factors have been associated with bleeding, platelet dysfunction being the most significant.Objective: to assess the effect of cardiopulmonary bypass machine (CPB) during cardiac surgery on platelet function using Platelet Function Analyzers (PFA-100), and Multiplate Electrode Aggregometry (MEA), and correlating that with a drop in Hemoglobin (Hb).Methods: Whole blood samples were collected preoperative and sixty minutes intraoperatively of different cardiac procedures utilizing (CPB) and tested for platelet function by PFA-100 and MEA. Complete blood count was measured using an automated hematology analyzer.Results: A significant difference was found between pre- and intraoperative ADP and EPI measurement in PFA-100, where preoperative PFA-ADP values displayed the ability to predict the intra-op drop in Hb (P–value 0.01, correlation coefficient 0.4699). At the same time, pre-op MEA- Ristocetin and TRAP showed an inverse correlation with an intra-op drop in Hb (-0.31 and -0.36). Conclusion: The current study reported significant changes in platelet dysfunction in cardiac surgeries with CPB, measured by two modalities PFA-100, and MEA. While PFA-100 and MEA both detected the changes in platelet dysfunction due to CPB, PFA-100 results were sensitive and positively predicted intra-op Hb drop as compared to MEA. There was a significant change in Hb one hour into the CPB, indicating that platelet transfusion might help decrease Intra- and postoperative bleeding independent of the platelet count as they are dysfunctional. PFA-100 results can be relied upon for distinction of high-risk cardiac surgery patients for bleeding and can be used for clinical decision making to improve patient outcome.