CHANGES IN PLATELET, GRANULOCYTE, AND COMPLEMENT ACTIVATION DURING CARDIOPULMONARY BYPASS USING HEPARIN-COATED EQUIPMENT

The effects of heparin-coated cardiopulmonary bypass (CPB) systems on platelet, granulocyte, and complement activation were investigated dur ing cardiopulmonary bypass. Thirty patients underwent coronary artery bypass surgery with a heparin-coated (Carmeda Bio-Active Surface, CBAS , Medtronic, U.S.A.) CPB system (HC group, n = 10), a heparin-coated o xygenator and uncoated CPB circuit (HO group, n = 10), or an uncoated system (UC group, n = 10). In the HO group, plasma C3a (1667 +/- 632 n g/ml) and C4a (1088 +/- 319 ng/ml) concentrations were significantly ( p < 0.05) lower than in the UC group (2846 +/- 1045 ng/ml and 1494 +/- 480 ng/ml, respectively) 10 min after the administration of protamine , but there were no significant differences in the platelet or granulo cyte counts. In the HC group, granulocyte elastase concentrations 120 min after the onset of CPB (365 +/- 177 mu g/L) and 10 min after the a dministration of protamine (676 +/- 314 mu g/L) were significantly (p < 0.05) lower than in the other 2 groups (820 +/- 341 and 893 +/- 303 mu g/L and 1365 +/- 595 and 1,258 +/- 622 mu g/L). In addition, the in crease in the plasma C3a concentration in the HC group 60 (p < 0.05) a nd 120 min after the onset of CPB (p < 0.05) was significantly less th an in the other 2 groups. The C3a and C4a concentrations 10 min after the administration of protamine were significantly (p < 0.005 and p < 0.05) less in the HC group than in the UC group. Platelet counts 10 mi n after the administration of protamine were significantly higher (p < 0.05) and plasma beta-thromboglobulin concentrations during CPB were significantly lower in the HC group than in the other 2 groups 5 (p < 0.05), 60, and 120 min (p < 0.005) after the onset of CPB. Postoperati ve blood loss during the first 12 h in the HC group was significantly (p < 0.05) less than that in the UC group. The heparin-coated oxygenat or and uncoated CPB circuit reduced complement activation but demonstr ated no significant effects on the platelet and granulocyte systems. H owever, the heparin-coated CPB circuit (with all components making blo od contact) reduced platelet, granulocyte, and complement activation a nd significantly reduced postoperative blood loss. Therefore, heparin coating of CPB systems improves biocompatibility.