NEUTROPHIL LEUKOTRIENE GENERATION INCREASES AFTER CARDIOPULMONARY BYPASS

Background: Leukotriene B-4 has been shown to play a role in the syste mic inflammatory response after cardiopulmonary bypass in experimental animal models; however, the importance of this mediator in human bein gs undergoing cardiac operations has not been established. Methods: Th e neutrophils of ten patients undergoing coronary artery bypass grafti ng with cardiopulmonary bypass were studied for their ability to gener ate leukotrienes at the time of the induction of anesthesia, the insti tution of cardiopulmonary bypass, the removal of the aortic crossclamp , at the end of the operation, on admission to the intensive care unit , and on postoperative days 1 and 2. Results: After cardiopulmonary by pass, the generation of chemotactic leukotrienes rose significantly an d remained elevated on the first postoperative day compared with preby pass values (prebypass 133.8 +/- 10.7 versus postbypass 192.7 +/- 19.2 [p < 0.05] and first postoperative day 196.6 +/- 13.8 [p < 0.05]). Th e increases in plasma complement and lactoferrin levels, although sign ificant, were not sustained. In addition to the neutrophil count, the potential leukotriene and oxygen radical produced was significantly in creased, and this increase was correlated with postoperative length of stay. Conclusion: These observations support the laboratory data docu menting that the rise in leukotriene generation after cardiopulmonary bypass includes human patients.