The Preconditioning Effect of Sevoflurane on Coronary Artery Bypass Surgery Patients

Background: One of the most important issues in the field of surgery is ischemic preconditioning (IPC) of the myocardium during the coronary artery bypass grafting (CABG). The current study attempted to reevaluate the issue to find a potential approach to diminish morbidity, inotrope administration, ischemia and possibly intensive care unit stay after CABG in adult patients.Materials and Methods: Through randomized single-blind clinical trial, all elective coronary bypass surgeries in 40 to 80 years-old patients enrolled the study. Atrioventricular (AV) block (mobitz2); complete heart block; left bundle branch block (LBBB); acute heart failure (ejection fraction (EF) <30%); re-exploration due to surgical complications and MI cases in the last 7 days were excluded. In all patients, induction (sufentanil, cis-atracurium and etomidate) and maintenance phase (sufentanil, midazolam, cis-atracurium) of anesthesia were done following the same protocol. After cross-clamp of aorta in intervention group, the patients received oxygen (2Lit/min) and sevoflurane (4%) during coronary bypass surgery. After rewarming of the patients, sevoflurane was discontinued. Main outcome measures were troponin 4, 8, 24, 48 hours after surgery with charting the electrocardiogram (ECG) changes, need for inotrope agents and hemodynamic indices during and after CABG in ICU.Results: 58 CABG candidates enrolled the current study: 29 in intervention group and 29 in control group. There were no statistical differences between the groups concerning hemodynamic issues, Central Venous Pressure (CVP), hematocrit (HCT), ECG changes, demands for inotrope, or ICU stay between the groups.Conclusion: No significant relationship between application of 4% sevoflurane and IPC was found in adult CABG patients. However, the effect of Sevoflurane on IPC might be dose-related.

Keywords:

Ischemic preconditioning (IPC) , Sevoflurane , Coronary Artery Bypass Surgery (CABG)