In high-risk patients, combination of antiinflammatory procedures during cardiopulmonary bypass can reduce incidences of inflammation and oxidative stress.

Previous studies showed that cardiopulmonary bypass (CPB) was directly associated with a global activation of the inflammatory response, production of oxygen free radicals, and signs of myocardial injury. We therefore evaluated, in the weakest patients, the biological and clinical benefits of a therapeutic optimization of CPB through the combination of several antiinflammatory procedures. High-risk patients undergoing cardiac surgery under CPB were included in this prospective randomized study. Control patients (n = 14) underwent conventional CPB, and treated patients (n = 13) underwent a CPB with Baxter Duraflo II heparin-coated circuits, high doses of aprotinin, and pre-CPB hemofiltration. Usual clinical hemodynamic and biological criteria, inflammation, and oxidative stress markers were measured before, during, and to the second postoperative day. Free radicals were quantified using electronic spin resonance spectroscopy with a spin trap. Significantly lower concentrations of C-reactive protein, interleukin-6, creatine kinase-MB, I-troponin, lactic acid, and systemic free radicals were observed in the plasma of treated patients. These patients had a reduction of postoperative complications and of the length of stay in the intensive care unit. Therefore, pre-CPB therapeutic optimization can reduce the inflammatory response, lower the level of oxidative stress, and help to ameliorate clinical outcome in high-risk patients.

Systemic free radical activation is a major event involved in myocardial oxidative stress related to cardiopulmonary bypass.

BACKGROUND: Cardiopulmonary bypass (CPB) can induce deleterious effects that could be triggered in part by radical oxygen species; however, their involvement in the course of surgery has been elusive. The aim of this study was to evaluate the time course and origin of radical oxygen species release, myocardial or not, in patients undergoing coronary artery surgery involving CPB. METHODS: Blood samples were taken from periphery and coronary sinus of patients during CPB, and oxidative stress was evaluated by direct and indirect approaches. Direct detection of alkyl and alkoxyl radicals was assessed by electron spin resonance spectroscopy associated with the spin-trapping technique using alpha-phenyl-N-tert-butylnitrone. RESULTS: The authors showed that the spin adduct concentration was not influenced by anesthesia and pre-CPB surgery. A rapid systemic increase of plasma spin adduct concentration occurred after starting CPB, and it stayed at a high concentration until the end of CPB. At the beginning of reperfusion period, radical oxygen species release was accelerated in the coronary sinus; however, it was not significant. A positive correlation was found between alpha-phenyl-N-tert-butylnitrone adduct concentrations and (1) the duration of CPB and (2) concentration of postoperative creatine phosphokinase of muscle band (CPK MB). Plasma vitamin E and C, ascorbyl radical, uric acid, thiol, plasma antioxidant status, and thiobarbituric acid reacting substances were also measured but did not give relevant indications, except for uric acid, which seemed to be consumed by the heart during reperfusion. CONCLUSION: The results indicate that a systemic production of free radicals occurs during CPB that may overwhelm the production related to reperfusion of the ischemic heart. This systemic oxidative stress is likely to participate in secondary myocardial damage.