Hemostasis after open-heart surgery with extreme or moderate hemodilution

Patients who received aortic disc valves during cardiopulmonary bypass (CPB) with extreme hemodilution, obtained with preoperative blood withdrawal, infusion of acetate solution and use of blood-free priming fluid, bled less than patients operated with moderate dilution. One hour after CPB with extreme dilution when the autologous blood had been reinfused, platelet adhesiveness was twice as high as in the moderate dilution group. Other parameters of platelet function, coagulation and fibrinolysis did not differ between the groups. The higher number of reactive platelets may therefore have contributed to the improved hemostasis after extreme dilution. Later, thrombocytosis with hyperreactive platelets and hyperfibrinogenemia developed in all patients. This might predispose for thrombosis.