Hemodynamic responses and myocardial ischemia in patients undergoing OPCAB surgery with either isoflurane or propofol anesthesia

Objective: To compare the effects of isoflurane inhalation anesthesia and propofol intravenous anesthesia on hemodynamics and myocardial ischemia in patients undergoing off pump coronary artery bypass.Methods: Sixty patients were randomized into two equal groups to receive isoflurane-based inhalation anesthesia or propofol-based intravenous anesthesia.In the two groups,0.8%-1.5% isoflurane in oxygen was inhalated and propofol 2-3 mg·kg^-1·h^-1was continuously infused,respectively.Total fentanyl doses were given up to 15-20 μg·kg^-1 for all cases. Hemodynamic measurements included mixed venous oxygen saturation（SvO₂）,heart rate（HR）,mean arterial pressure（MAP）,mean pulmonary artery pressure（MPAP）, pulmonary capillary wedge pressure（PCWP）,cardiac index（CI）,systemic vascular resistance index（SVRI）,pulmonary vascular resistance index（PVRI） and central venous pressure（CVP）.Automated ST segment trends were analysed from leads II.Requirement of inotropes were recorded.Results: The two groups did not differ with respect to preoperative and operative data.MAP dropped more pronounced during anastomasis on the left anterior descending artery and the branches of circumflex in the two groups,and was consistent with the decrease of CI.Both SVRI and PVRI decreased along with the decrease of MAP andCI,the tendency showed more notable in propofol group.SvO₂decreased significantly during manipulations in both groups（P＜0.05）.All hemodynamic parameters did not differ between the two groups.The use of vasoactive drugs（phenylephrine or/and dopamine） and ST segment changes were similar in the two groups.Conclusion: For either isoflurane inhalation anesthesia or propofol intravenous anesthesia,the hemodynamics,ECG changes and requirement of inotropes intraoperatively are comparable.All the hemodynamic changes are well tolerated by all patients.