The influence of the duration of cardiopulmonary bypass on coagulation, fibrinolysis and platelet function

Background: The duration of cardiopulmonary bypass (CPB) might influence bl ood coagulation. This appears particularly relevant in the light of new, le ss invasive techniques that propose smaller incisions at the expense of a p ossible prolongation of time on CPB. Methods: The time-dependent effects on coagulation, fibrinolysis and platelet function were investigated in 94 pa tients scheduled for elective coronary artery bypass grafting. Tests on coa gulation, fibrinolysis, and platelet function (flow cytometric assay of exp ression densities of glycoprotein IIb/IIIa and P-selection were performed t he day before surgery and after completion of surgery. Results: A significa nt correlation was found between the duration of CPB and parameters of incr eased coagulation, decrease of platelet counts during CPB and platelet func tion. Longer duration of CPB led to an increased need for transfusion of re d blood cells. Conclusions: The duration of CPB affects thrombin formation as well as platelet count and function, but not the fibrinolytic system. Th is may prove to be a disadvantage when employing minimally invasive techniq ues that prolong the duration of CPB.