Effects Of Sevoflurane Washed In During Cardiopulmonary Bypass On Myocardial Injury In Patients Undergoing Coronary Artery Bypass Grafting

Objective To observe the changes of perioperative hemodynamics, myocardial morphology,24-h ambulatory electrocardiography, plasma cTnI concentrations and CK-MB activities between washing in1.0%sevoflurane through the gas mixture delivered to the oxygenator and routine cardiopulmonary bypass in patients undergoing coronary artery bypass graft surgery. To investigate the feasibility and science of the effects of sevoflurane washed in during cardiopulmonary bypass(CPB) on myocardial injury in patients undergoing CABG surgery.Methods Forty ASA II or III patients aged50-64yr, weighing53-90kg, scheduled for CABG under CPB were randomly divided into2groups (n=20):control group (group C) routine CPB; sevoflurane group(group S) washing in1.0%sevoflurane during CPB through the gas mixture delivered to the oxygenator. There were no premedication in all patients. In the operating room, all patients received routine monitoring, including five-lead electrocardiography, radial artery catheters with blood pressure, pulse oximetry, capnograhy. Anesthesia was indued iv with0.05mg/kg midazolum,0.3mg/kg etomidate,1μg/kg sufentanil and0.6mg/kg rocuronium to facilitate tracheal intubation and mechanical ventilation; then right internal jugular vein was cathetered for monitoring CVP. Anesthesia was maintained with propofol3-5mg·kg-1·h-1and sufentanil0.5-1.0μg·kg-1·h-1in both groups, and1.0%sevoflurane was washed in during CPB in group S. The patients were monitored with Holter within24h after operation for analysis of12-lead dynamic ECG. Global hemodynamic variables for subsequent statistical analysis(i.e., heart rate, mean arterial pressure, central venous pressure, rate-pressure product) were recorded5min after induction,5min before CPB, immediately after CPB,0,6h,12h,24h after operation. CPB time, cross-clamp time, mechanical ventilation time, surgery time, ICU stay and in-hospital time, the doses of dopamine and anesthetic medicines were recorded. Blood samples were taken from radial artery after the induction of anesthesia and6,12,24h after operation for determination of plasma cardiac troponin I(cTnl) concentration and creatine kinase-MB (CK-MB) activity. The blood sugar concentrations were tested immediately before skin incision,20min before CPB, 60min after CPB. Myocardial tissues were obtained from right auricle before aortic clamping and at the end of CPB for ultrastructure observation and the severity of mitochondria injury assessment.Results1, There were no significant differences in the characteristics of the patients, operative conditions, post-operative conditions (P>0.05). The incidence of atrial fibrillation and myocardial ischemia were separately30%,20%in group C, and25%,25%in group S, there was no significant differences between two groups (P>0.05).2, There was no significant difference in the perioperative hemodynamic variables (P>0.05).3, Compared with group C, plasma cTnl concentration was decreased at12h and24h after operation in group S (P<0.05). Plasma cTnl concentration was decreased at12h and24h after operation than that at6h after operation in the two groups (P<0.05or0.01).There was no significant difference in plasma CK-MB activity between the two groups (P>0.05).4, Compared with group C, the mitochondria injury score was decreased after the end of CPB in group S (P<0.05).5, The blood sugar concentrations were increased at20min before CPB and60min after CPB than at immediately skin incision. There was no significantly different between two groups.Conclusion Sevoflurane (1.0%) washed in during CPB for the patients undergoing CABG were not only safety but can attenuate myocardial injury.