Cardioprotective Effects Of Sevoflurane Preconditioning In Patients Undergoing Single Valve Replacement With Cardiopulmonary Bypass

Objective:Volatile anaesthetics have been shown to exert cardioprotective properties in experimental and clinical studies. However, the mode of administration may influence these cardioprotective effects. The present study was designed to compare the effect of interrupted administration of sevoflurane before cardiopulmonary bypass with continuous sevoflurane administration and with propofol-only anaesthesia, on cardioprotection as assessed by myocardial cell damage during cardiac surgery.Methods:From September 2009 to March 2010, in the second hospital of ShanDong University, Forty-five ASAⅡorⅢpatients undergoing single valve replacement with cardiopulmonary bypass including mitral valve replacement and aortic valve replacement patients were randomly divided into 3 groups (n=15):propofol-only group (P group), continuous(SC group) and interrupted sevoflurane administration group (SI group). The premedication and anesthesia induction of three groups are same.Anesthesia maintenance:P Group continuous infusion of propofol 3-4mg/(Kg·h);Patients in SC group were inhaled 2MAC sevoflurane from the success of intubation to the beginning of cardiopulmonary bypass,and during and after CPB, anaesthesia was maintained with propofol 3-4 mg/(Kg·h); Patients in SI group were treat with interrupted administration of sevoflurane before cardiopulmonary bypass, each at least intermittent-eluting lOmin, eluted twice in total. During and after CPB, anaesthesia was maintained with propofol 3-4 mg/(Kg·h). During anesthesia was maintained, in all groups, before skin incision, sternotomy, and CPB,patients were given fentanyl lOug/Kg, when necessary, vecuronium bromide were given to maintain muscle relaxation.Before operation and at 15 and 30 min after weaning from CPB, we record hemodynamics (such as heart rate, mean arterial pressure, central venous pressure, cardiac index CI), and observe the situation of cardiac autonomic rhythm recovery after the opening of aorta. Record the cardioplegia volume, the lowest nasopharyngeal temperature,the length of stay in ICU after operative, the length of stay in hospital, and postoperative cardiac adverse event respectively.Immediately before induction of anesthesia (To), after CPB 6h (Ti),24 h (T2) we collect radial arterial blood to detect plasma creatine kinase isoenzyme (CK-MB), cardiac troponin I (cTnI), brain natriuretic peptide (BNP), C-reactive protein (CRP), interleukin IL-6, IL-10 levels,and observe cardiac autonomic rebeating situation after the opening of aortic. Results:Comparison of hemodynamic parameters:At 15min and 30min after CPB, heart rate of SC group was faster than the other two groups(P<0.05). At 15min and 30min after CPB, ejection fraction of SC group is higher than the other two groups(P<0.05).Recovery rates of cardiac autonomic jump in SI and SC groups were higher than the P group (P<0.O5). Patients in three groups had no adverse cardiac events.Comparison of biochemical index:Up to 6h and 24h after cardiopulmonary bypass, in group SI, postoperative cTnI values were significantly (P<0.05) lower than both the P and SC groups. CRP levels were also significantly (P<0.05) lower in the SI group at 6h and 24h after cardiopulmonary bypass compared with both the P and SC groups. There was, however, no significant difference in inflammatory cytokines (IL-6, IL-10), BNP, CK-MB levels and length of stay in either the intensive care unit or in the hospital in the three groups(P>0.05).Conclusion:We conclude that prior interrupted sevoflurane administration confers some cardioprotection as compared with continuous sevoflurane administration or propofol-based anaesthesia, and showed less myocardial cell damage。...