MicroRNA Mediates Volatile Anesthetics Preconditioning Induced Artery Protection

1. Sixty patients scheduled for off-pump coronary artery bypass surgery were randomly assigned to isoflurane wash-in/wash-out group(S-I group, n=30)or propofol intravenous anesthesia group(P group, n=30). 2. Anesthesia and monitoring method All patients were monitored according to the American Society of Anesthesia guidelines and received standard general induction of anesthesia. 3. SI group:10min after intubation,begin to isoflurane wash-in/wash-out operation:isoflurane administration was interrupted for at least 10 min,by washout with a high fresh gas flow(10 l/min)to achieve a MAC value below 0.2. Following the interruption,sevoflurane was again washed in with a high fresh gas flow(6 l/min)to achieve 1 MAC end-tidal concentration as soon as possible,and repeated twice periods of 10 minutes.Discontinuation of the halogenated agent for at least 15 minutes during the last wash out time. 4. P Group:propofol infusion 3-5μg/kg/h. 5. When isoflurane inhaled anesthetic,propofol are stopped infusion.If during this interruption the BIS value increased to\>50,0.5 mg/kg propofol was administered repeatedly in boluses until the BIS value have returned to\<50. 6.1h after isoflurane preconditioning,specimens of internal mammary artery(surplus arterial tissue is obtained from the repair internal mammary artery)and ascending aorta(the stump after ascending aortic punch)will be saved, and before isoflurane preconditioning,1h,3h,5h after isoflurane preconditioning, central venous blood samples will also be drawn.