Early postoperative cognitive recovery and gas exchange patterns after balanced anesthesia with sevoflurane or desflurane in overweight and obese patients undergoing craniotomy

Overweight and obese patients are at especially high risk for delayed awakening after general surgery. Whether this risk also applies to cerebral neurosurgical procedures remains unclear. This study evaluated early postoperative cognitive recovery and gas exchange patterns, after balanced anesthesia with sevoflurane or desflurane, in overweight and obese patients undergoing craniotomy for supratentorial expanding lesions. Fifty-six patients were consecutively enrolled, and randomly assigned to 1 of 2 study groups to receive balanced anesthesia with sevoflurane or desflurane. Cognitive function was evaluated with the Short Orientation Memory Concentration Test and the Rancho Los Amigos Scale and gas exchange patterns (pH, PaO2, and PaCO2) were recorded in all patients at 5 time-points: preoperatively and postoperatively, after patients reached an Aldrete score Z9, at 15, 30, 45, and 60 minutes. Preoperative cognitive status was similar in the 2 treatment groups. Early postoperative cognitive recovery was more delayed and Short Orientation Memory Concentration Test scores at 15 and 30 minutes postanesthesia were lower in patients receiving sevoflurane- based anesthesia than in those receiving desfluranebased anesthesia (21.5±3.5 vs. 14.9±3.5) (P<0.005) and (26.9±0.7 vs. 21.5±1.4) (P<0.005), and the postoperative Rancho Los Amigos Scalegrade 8 showed a similar trend (25/28 patients 89% vs. 8/28 patients 28% (P<0.005) and 28/28 patients (100% vs. 13/28 patients 46%) (P<0.005). Similarly, gas-exchange analysis showed higher PaCO2 at 15 and 30 minutes and lower pH up to 45 minutes postextubation in patients receiving sevoflurane-based anesthesia. In overweight and obese patients undergoing craniotomy desflurane-based anesthesia allows earlier postoperative cognitive recovery and reversal to normocapnia and normal pH. Key Words: neuroanesthesia, postoperative