N-乙酰半胱氨酸对体外循环下心脏瓣膜置换术患者心肌缺血再灌注损伤的影响

Objective To investigate the effects of N-acetylcysteine(NAC)on myocardial ischemia-reperfusion(I/R)injury in patients undergoing cardiac valve replacement under cardiopulmonary bypass(CPB).Methods Twenty-two ASA Ⅱ or Ⅲ patients of both sexes aged 21-60 yr undergoing cardiac valve replacement under CPB were randomly assigned to one of 2 groups(n=11 each):control group(group C)and NAC group.In NAC group NAC 100 mg/kg was added to the priming solution and 50 mg/kg to crystalloid eardioplegic solution,while in control group normal was used instead of NAC.Swan-Gang catheter was placed.Heart rate(HR),mean arterial pressure(MAP),central venous pressure(CVP),pulmonary medal pressure(PAP),pulmonary capillary wedg pressure(PCWP),cardiac output(CO)and cardiac index(CI)were recorded at 10 min beforeanesthesia induction and at the end of operation.Blood samples were collected before operation and at 0.5,6,12 and 24 h after release of the aortic cross-clamp for determination of blood gas analysis,plasma IL-6,TNF-α,MDA and cTnI concentrations and SOD activity.Myocardial specimens were obtained from right atrium for detection of apeptosis(by TUNEL)and examination of ultrastructure with scanning electron microscope.Results There was no significant difference in HR,MAP,CVP,PAP,PCWP,PaO2,Hct,PaCO2,pH value and BE between bothgroups.The plasma concentrations of MDA,IL-6,TNF-α and eTnI weFe significantly lower,while plasma SOD activity CO and CI were higher in group NAC than in group C.NAC significantly decreased myocardial apeptosis and damage induced by myocardial I/R during CPB.Conclusion NAC can protect myocardium against I/R injury induced by CPB.

Effects of N-acetylcysteine on myocardial ischemia-reperfusion injury in patients undergoing cardiac valve replacement under CPB