Inclusion of sevoflurane in cardioplegia reduces neutrophil activity during cardiopulmonary bypass.

The purpose of this study was to examine the effects of sevoflurane cardioplegia on neutrophil response and complement activation after cardiopulmonary bypass (CPB).A prospective, randomized clinical investigation.University-affiliated hospital; single institutional.Twenty-one male patients undergoing coronary bypass surgery using CPB.Eleven patients were randomly assigned to receive sevoflurane 2% as a part of the cardioplegic mixture (SEV). The control group (n = 10) received no sevoflurane in their cardioplegia (control).Myeloperoxidase activity (MPO) was assayed in coronary sinus blood as a surrogate for neutrophilic response at the termination of CPB. MPO activity in the coronary sinus blood was lower in the patients who received sevoflurane compared with controls. MPO activity was higher in patients with cardiac events at 4-year follow-up when compared with asymptomatic patients. IL-8, C4b, C3d, C5a, and CH50 were assessed in coronary sinus and peripheral blood at time of CPB initiation (T0) and upon the termination of CPB (T2). Peripheral blood sampling occurred at the sixth hour after T0 (T6). IL-8 levels were significantly inhibited in the SEV group when compared with controls at T2 and T6. CH50 (an index of global activation of complement system) decreased 30% at T2 and 52% at T6. The classic component of the complement pathway (C4b) was effectively inhibited in the SEV group, whereas the common pathway (C3d and C5a) was similar in both groups.The addition of sevoflurane to cardioplegia is associated with an inhibition of neutrophils after CPB. A major component of the neutrophil response appears to be IL-8 mediated, although the classic complement pathway is also inhibited by sevoflurane.