INFLUENCE OF CARDIOPULMONARY BYPASS ON PLATELET AND NEUTROPHIL ACCUMULATIONS IN INTERNAL ORGANS

The authors employed gamma scintigraphy to quantify the post bypass ac cumulations of platelets and neutrophils in the lung, liver, and heart of adult pigs subjected to a standard 90 min regimen of normothermic cardiopulmonary bypass (CPB). Coated and uncoated microporous polyprop ylene oxygenator circuits were studied for Cobe Duo (Arvada, CO) oxyge nators (amphophilic silicone-caprolactone oligomer [SMA] coating, n = 8 each) and Medtronic Maxima (Irvine, CA) oxygenators (Carmeda heparin coating, n = 5 each). Images of cells in the organs (deposited + bloo d pool) were corrected for tissue absorption and other factors and com pared for a 2 hr period post CPB, using repeat measures ANOVA and rank tests. Platelet accumulations in internal organs correlated positivel y with whole blood platelet counts and negatively with platelet deposi ts in oxygenators during CPB. In general, uncoated CPB circuits signif icantly reduced platelet and neutrophil accumulations in lung, liver, and heart versus preCPB controls for the post CPB interval, for both s ystems. The SMA treatment significantly increased platelet accumulatio ns versus uncoated controls in lung, liver, and heart for the 2 hr per iod, including the majority of the post CPB sampling intervals; platel et densities did not reach preCPB levels. Neutrophil accumulations wer e unaffected by the SMA coating. Carmeda heparin treatment significant ly increased platelet accumulations in the liver, but not lung or hear t. Despite preservation of circulating neutrophils observed with the C armeda heparin treatment, neutrophil accumulations in internal organs were not elevated post CPB.