Effect Of Sufentanil Postconditioning On Myocardial Ischemia-reperfusion Injury In Cardiac Valve Replacement Patients

Objective Myocardial ischemia-reperfusion injury is a common complication in cardiacvalve replacement surgery and affect the recovery of cardiac function. It is veryimportant for us to seek effective measures to reduce myocardial ischemia-reperfusioninjury. The aim of this study is to investigate the effect of different dose of sufentanilpostconditioning on myocardium ischemia-reperfusion injury in patients undergoingcardiac valve replacement and investigate the mechanism.Methods Sixty patients （ASA grade II or III, NYHA class II or III） of both sexesaged19-64, scheduled for cardiac valve replacement were randomly divided into4groups （n=15each）: normal saline control group （group C）, sufentanil0.5μg·kg^-1group（group S1）, sufentanil1μg·kg^-1group （group S2） and sufentanil2μg·kg^-1group （group S3）.The patients respectively received2min of infusion via aortic root5min before aorticunclamping. In group C, equal volume of normal saline(2ml·kg^-1) was infused. Ingroups S1, S2and S3,0.5μg·kg^-1,1μg·kg^-1and2μg·kg^-1of sufentanil (2ml·kg^-1) wereinfused for2min respectively. Blood samples were taken from radial artery beforeinduction of anesthesia （T₀） and at2h （T1）,4h （T₂）,8h （T₃）,24h （T₄） and48h （T₅） afteraortic unclamping for determination of plasma concentrations of cardiactroponin-I（cTnI）, CK-MB, NOS, NO, MDA and SOD. Mean arterial pressure（MAP）and heart rate（HR） were recorded before induction of anesthesia （T_a）,immediatelybefore CPB（T_b）, immediately before postconditioning（T_c）, at the time of aortic unclamping（Td） and at10min after aortic unclamping（T_e）. The time of CPB and aorticclamping, the spontaneous recovery of heart beat, extubation time and ICU duration,postoperative myocardial contraction score and drainage volume24hours after theoperation and cardiovascular events were recorded.Results The case of patients, MAP and HR,the CPB time, the aortic clamping time,the rate of recovery of spontaneous heart beat and the drainage volume24hours afterthe operation were no significant difference between the four groups （P>0.05）. At T₀the plasma cTnI, CK-MB, NOS, NO, SOD and MDA concentrations were no significantdifference between the four groups （P>0.05）. Compared with group C,the plasma cTnI,CK-MB and MDA concentrations were significantly lower, while the plasma NOS, NOand SOD concentration was significantly higher at T_1³in group S1,the plasma cTnI andCK-MB concentrations were significantly lower at T_1⁵in groups S2and S3,the plasmaMDA concentration was significantly lower, while the plasma NOS, NO and SODconcentration was significantly higher at T_1⁴in groups S2and S3（P<0.05）. Comparedwith group S1,the plasma cTnI and CK-MB concentrations were significantly lower atT_4⁵in groups S₂and S₃,the plasma MDA concentration was significantly lower at T₄,while the plasma NOS, NO and SOD concentration was significantly higher at T_3⁴ingroups S₂and S₃（P<0.05）. The time of extubation and ICU duration, postoperativemyocardial contraction score24hours and the incidence of cardiovascular events weresignificantly lower in groups S2and S3than in group C （P<0.05）. The myocardialcontractility score at24h after the operation was significantly lower in groups S₂and S₃than in group S1（P<0.05）.There was no significant different between groups S2and S₃（P>0.05）Conclusions Sufentanil postconditioning can relieve myocardial ischemiareperfusion injury in patients undergoing cardiac valve replacement under CPB, which may be dose-dependent and ceiling-effective, and one of the mechanisms may be theinhibition of oxidative stress reaction by activating the NOS/NO pathway.