Need of Inotrope in Coronary Artery Bypass Grafting with two Methods of Anesthesia

Propofol’s unique pharmacokinetic profile offers advantages for rapid emergence in patients after coronary artery bypass graft surgery. However, concern for negative inotropic properties potentially limits its usage in these patients. The present study was undertaken to compare the hemodynamic effects of anesthesia, with propofol base versus morphine base, on usage of inotrope during weaning off cardiopulmonary bypass. This study was conducted on 60 patients with A.S.A II, III, EF>35% without history of recent myocardial infarction. We randomized 60 patients undergoing CABG surgery to receive either a propofol-based (propofol 50 μ g/kg/min+ fentanyl 0.1 μ g/kg/min as infusion) or morphine-based (morphine 0.3-0.4 mg/kg+Midazolam 0.1-0.15 mg/kg as bolus) anesthesia during pump. Either group underwent general anesthesia similarly (midazolam 0.1-0.15 mg/kg, Morphine 0.3-0.4 mg/kg, thiopental 3-4 mg/kg and pancuronium bromide 0.15 mg/kg) and it was maintained with halothane 0.5% O2+N2O (50%/50%). The requirement to inotrope was assessed by mean arterial blood pressure(BP) and central venous pressure(CVP). If CVP was more than 14 mmHg and mean BP was less than 80 mmHg we started infusion of epinephrine 0.02 μ g/kg/min that was increased to 0.5 μ g/kg/min. Thirty-seven of the patients required inotrope, out of whom, 24 patients received morphine-based anesthesia and 13 patients received propofol anesthesia(P<0.05). The result of this trial suggests that a morphine-based anesthesia requires additional inotrope support during weaning off CPB in contrast to a propofol-based anesthesia.