BIOCOMPATIBILITY OF HEPARIN-COATED MEMBRANE-OXYGENATOR DURING CARDIOPULMONARY BYPASS

The biocompatibility of the cardiopulmonary bypass (CPB) circuit, in w hich an oxygenator is solely heparinized, was assessed by systemic inf lammatory reactions as an indicator during CPB. Fourteen patients, 11 males and 3 females, underwent coronary artery bypass surgery and were randomly divided into 2 groups of 7 patients each. For the heparin-co ated oxygenator group (Group H), a heparin-coated membrane oxygenator was used in the CPB circuit, and in the control (Group C) an uncoated membrane oxygenator was employed. Systemic inflammatory reactions, suc h as platelet activation, prostaglandin production, complement activat ion, and activated granulocyte released substance, were measured prior to, during, and 6 h after CPB. The number of platelets decreased afte r protamine administration in both groups (14.5 +/- 4.7 x 10(4)/mu l i n Group H and 13.8 +/- 8.7 x 10(4)/mu l in Group C) and returned to ba seline levels in Group H while it remained decreased in Group C at 6 h after CPB. The platelet factor 4 level was significantly lower in Gro up H (181 +/- 40 ng/ml) than in Group C (297 +/- 131 ng/ml) after prot amine administration. Thromboxane-B-2 (TXB(2)) rose during CPB in both groups; however, there were significantly different levels of TXB(2) between the 2 groups at 60 min after CPB (293 +/- 258 pg/ml in Group H versus 408 +/- 120 pg/ml in Group C) and after protamine administrati on (259 +/- 122 pg/ml in Group H versus 709 +/- 418 pg/ml in Group C). Plasma concentrations of granulocyte elastase were significantly lowe r in Group H at 30, 60 and 90 min, immediately after, and post-CPB tha n those of Group C. Although the oxygenator was solely heparinized in the CPB circuit, it was sufficiently effective to reduce inflammatory reactions during coronary artery bypass operation, and the heparin-coa ted surface seems to be more endothelium-like.