HEMOSTASIS AT LOW HEPARIN DOSAGE DURING CARDIOPULMONARY BYPASS WITH HEPARIN-COATED CIRCUITS IN PIGS (VOL 31, PG 275, 1997)

Cardiopulmonary bypass (CPB) causes activation of cascade systems. Alt hough heparin coating of CPB circuits improves biocompatibility, the e ffects on coagulation remain controversial. Theoretically, heparin coa ting should permit the reduction of systemic anticoagulation during CP B. We investigated influences on haemostatic variables in animal CPB, comparing heparin-coated circuits and reduced systemic heparinization (group HC) with uncoated circuits and full heparinization (group C). T wenty pigs underwent 2-h CPB. Seven (HC, n = 4; C, n = 3) were weaned from CPB and studied for up to 4 h. Total administered heparin was 470 +/- 6 IU/kg (mean +/- SEM) in group C and 100 +/- 0 IU/kg in group HC . Protamine dosage was significantly reduced in group HC. In group C, levels of prothrombin complex, factor VIII and adhesive platelets were reduced significantly during CPB, and postoperatively there were sign ificantly lower values of prothrombin complex, fibrinogen, antithrombi n III, factor VIII and adhesive platelets but a significantly increase d concentration of von Willebrand factor and cumulative bleeding after 4 h. In conclusion, heparin-coated CPB circuits combined with lowered heparin dosage reduced coagulation factor consumption and preserved p latelet function, possibly contributing to improved postoperative haem ostasis.