INFLAMMATORY MEDIATORS IN ADULTS UNDERGOING CARDIOPULMONARY BYPASS - COMPARISON OF CENTRIFUGAL AND ROLLER-PUMPS

Background. The nonocclusive centrifugal pump is used for cardiopulmon ary bypass (CPB) and mechanical cardiac assistance. This study examine d its impact on proinflammatory cytokine release. Methods. Forty-one p atients undergoing elective coronary artery bypass grafting were rando mized prospectively to either a standard roller pump group (n = 21) or a centrifugal vortex pump group (n = 20) for CPB. The two groups were well matched in age, sex, severity of disease, and duration of CPB an d aortic cross-clamping. Plasma levels of the cytokines tumor necrosis factor-alpha; interleukin-1 beta, interleukin-6, and interleukin-8, a s well as terminal complement, neutrophil counts, and leukocyte elasta se, were analyzed before, during, and after CPB. Results. In both grou ps, traces of tumor necrosis factor-cu were observed infrequently and interleukin-1 beta was not detected. Plasma levels of interleukin-6 an d interleukin-8 increased during and after CFB, reaching a peak at 2 h ours after protamine administration in both groups before returning to ward baseline at 24 hours. The release of interleukin-6 was significan tly greater in the centrifugal group (p < 0.05), whereas the interleuk in-8 concentration did not differ between the groups throughout the st udy period. Levels of terminal complement increased in both groups per ioperatively, reaching a peak 30 minutes after protamine administratio n, whereas neutrophil counts and elastase peaked 2 hours after protami ne administration. Plasma terminal complement, neutrophil counts, and elastase release were significantly higher in the centrifugal group (p < 0.05). Peak terminal complement correlated (r = 0.64, p < 0.01) wit h peak elastase in the centrifugal group only. Conclusions. This study confirms the proinflammatory nature of CPB in adults and demonstrates that use of the centrifugal pump induces a greater systemic inflammat ory response than use of the standard roller pump. (C) 1998 by The Soc iety of Thoracic Surgeons.