Comparison of propofol-based versus volatile-based anaesthesia and postoperative sedation in cardiac surgical patients: a prospective, randomized, study.

Background: Clinical trials have shown conflicting results regarding the use of volatile anaesthesia before or after an ischaemic insult in cardiac surgical patients and its effect on myocardial injury. This may be attributable to the failure of continuing volatile agents into the early postoperative period. We hypothesised that combined volatilebased anaesthesia and postoperative sedation would decrease the extent of myocardial injury after coronary artery bypass grafting (CABG) when compared with an intravenous, propofol-based approach. This study aimed to assess the feasibility of the perioperative protocol and investigate whether volatile anaesthesia provides cardioprotection in patients undergoing CABG.

Methods: Randomized, controlled trial enrolling 157 patients with preserved left ventricular function scheduled for elective or urgent on-pump CABG. Patients received either volatile- or propofol-based anaesthesia and postoperative sedation. Volatile sedation in the ICU was provided with the use of the AnaConDa® device (Sedana Medical, Uppsala, Sweden). The primary outcome was myocardial injury measured by serial troponin measurement at the beginning of surgery, 2, 4 and 12-16 h after ICU admission. The secondary outcome was cardiac performance expressed as cardiac index (CI) and the need for inotropic and vasopressor drug support. The peak postoperative troponin level was defined as the highest level at any time in the first 16 h after surgery.

Results: 127 patients completed the study protocol, 60 patients in the volatile group and 67 patients in the propofol group. Troponin levels were similar between groups at all of the measured time points. There were no differences in cardiac index or vasoactive drug support except for the immediate post- cardiopulmonary bypass (CPB) period when patients in the volatile group had low systemic vascular resistance, high CI and required more vasopressors. There was no difference in postoperative kidney function, intensive care unit discharge or hospital discharge time.

Conclusions: The use of volatile-based anaesthesia and postoperative sedation did not confer any cardioprotection compared with propofol-based anaesthesia and sedation in patients who had good left ventricular function and were undergoing CABG.