Thoracic Epidural Anesthesia Preserves Myocardial Function During Intraoperative and Postoperative Period in Coronary Artery Bypass Grafting Operation

Abstract

Aim. The purpose of this study was to investigate the effect of thoracic epidural anesthesia (TEA) in patients with poor ventricular function undergoing conventional coronary artery bypass graft surgery (CABG) during the intraoperative and the postoperative period. Methods. Eighty patients (n=80) undergoing elective CABG surgery with cardiopulmobary bypass (CPB) were divided into 4 groups: 1) General anesthesia (GA) plus poor ventricular (PV) function patients (Group GA plus PV) (n=20) ejection fraction (EF) <= 40%

2) GA plus good ventricular (GV) function patients (Group GA plus GV) (n=20) EF > 40%

3) Thoracic epidural anaesthesia (TEA)+GA poor ventricular function patients (Group TEA+GA plus PV) (n=20) EF less than or equal to 40%

4) TEA+GA good ventricular function patients (Group TEA+GA plus GV) (n=20) EF > 40%. Results. Within groups at 4 h after the end of CPB in the Group TEA+GA plus PV and Group TEA+GA plus GV the cardiac index values were significantly higher than baseline values

P < 0.05 whereas no difference was found in the Group GA plus PV and Group GA plus GV. According to Tukey test using repeated measures between trend of groups the cardiac index values were significantly different P < 0.05. In the Group TEA+GA plus PV cardiac index values were significantly higher than the Group GA plus PV P < 0.05. But in the Group GA plus GV cardiac index values were not significantly different than the Group TEA+GA plus GV. The incidence of reperfusion ventricular fibrillation (VF) after release of aortic cross-clamp in the Group TEA+GA plus PV (4 of 20 patients: 20%) was significantly lower than in the Group GA plus PV (11 of 20 patients: 55%)

P < 0.05. The incidence of reperfusion VF after release of aortic cross-clamp in the Group TEA+GA plus GV (5 of 20 patients: 25%) was not significantly different than in the Group GA plus GV (10 of 20 patients: 50%)

NS. Conclusion. TEA seems to be effective in patients with poor left ventricular function. Our results (improved cardiac index reduced arrhythmias after release of aortic clamp and decreased inotropic requirement) are better with TEA particularly in patients with poor left ventricular function.