Sevoflurane Postconditioning Induces Cardioprotection Of Myocardium Ischemia-reperfusion Injury In Human Undergoing Coronary Artery Bypass Grafting

Objection To investigate the safety and myocardial protection effect of sevoflurane postconditioning in different concentration and administration mode for patients undergoing coronary artery bypass grafting(CABG) surgery.Methods 75 patients undergoing CABG were divided into 5 groups by randomized,controlled and single-blind methods. Total intravenous anesthesia was applied in all the patients. There was no special treatment in control group(Cont). In APOC-1 group,15 patients continuously inhaled sevoflurane at 1.0MAC for 15 minutes as the anastomotic of mammary artery to anterior descending artery was released. In APOC-2 group,15 patients continuously inhaled sevoflurane at 2.0MAC for 15 minutes as the anastomotic was released. In APOI-1 group,15 patients inhaled sevoflurane at 1.0MAC for 5 minutes first, then interrupted for 5 minutes, then continued for 5 minutes, total 15 minutes as the anastomotic was released. In APOI-2 group,15 patients inhaled sevoflurane at 2.0MAC for 5 minutes first, then interrupted for 5 minutes, then continued for 5 minutes, total 15 minutes as the anastomotic was released. The changes of myocardial morphology,perioperative hemodynamics,myocardial enzymology and the quantity of troponin I were observed.Results All the patients completed the trial and were discharged without obvious side effects. The perioperative materials were no different among groups(p>0.05). During CPB, the dosage of norepinephrine used in APOC-2 was significant larger than control group(p<0.05), and the other hemodynamic data among groups were no different(p>0.05). CK, CK-MB, LDH and cTnI in the blood plasma increased strikingly at 6h after reperfusion and 24h after the surgery was over compared with baseline in all 5 groups(p<0.05). Compare with the control group, the level of cTnI in the blood plasma was significant lower at 6h after reperfusion and 24h after the surgery was over in APOC-2 (p<0.05). The changes of myocardial morphology were no significant different among groups before cardiopulmonary bypass(CPB), but the injury of myocardium in sevoflurane postconditioning groups were lighter than that of in control group after CPB. Compare with the changes of myocardial morphology before CPB, they were lightly in postconditioning groups after CPB. But they aggravated dramatically in control group.Conclusion Using different even high concentrations and administration mode sevoflurane postconditioning are safe for patients undergoing coronary artery bypass grafting(CABG) surgery,and 2MAC continuously 15 minutes sevoflurane postconditioning has significant myocardial protection effect.