EFFECTS OF APROTININ DURING CARDIOPULMONARY BYPASS IN PATIENTS TREATED WITH ACETYLSALICYLIC-ACID

Of 35 acetylsalicylic acid (ASA)-treated patients undergoing coronary artery bypass surgery, 10 received a high dose of aprotinin (mean 5.2 x 10(6) KIU) during cardiopulmonary bypass (CPB); in 15 cases low-dose aprotinin (2 x 10(6) KIU) was added to the CPB priming solution, and 10 patients made up a control group without aprotinin. Median total bl ood loss was 52% less in aprotinin-treated patients, irrespective of d ose, than in the controls. Fibrin-D dimer levels remained low in patie nts treated with high-dose aprotinin, but increased significantly in t he control group. Platelet adhesion and platelet adenosine triphosphat e secretion were reduced after CPB in all patients. Whole-blood aggreg ation after bypass was enhanced in aprotinin-treated patients. Aprotin in inhibited fibrinolysis and seemingly preserved platelet function de spite ASA treatment. In view of the possible risks and relatively high cost of aprotinin, use of a high dose seems unnecessary, since a low dose was equally effective in reducing blood loss in ASA-treated patie nts.