Titration of sevoflurane in elderly patients: blinded, randomized clinical trial, in non-cardiac surgery after beta-adrenergic blockade

Abstract

Monitoring depth of anesthesia via the processed electroencephalogram (EEG) has been found useful in reducing the amount of anesthetic drugs, optimizing wake-up times, and, in some studies, reducing awareness. Our goal was to determine if titrating sevoflurane as the maintenance anesthetic to a depth of anesthesia monitor (SEDLine™, Masimo, CA) would shorten time to extubation in elderly patients undergoing non-cardiac surgery while on beta-adrenergic blockade. This patient population was selected because the usual cardiovascular signs of inadequate general anesthesia may be masked by beta-blocker therapy. Surgical patients older than 65years of age receiving beta-adrenergic blockers for a minimum of 24h preoperatively were randomized to two groups: a group whose titration of sevoflurane was based on SEDLine™ data (SEDLine™ group) and a group whose titration was based on usual clinical criteria (control group) where SEDLine™ data were concealed. The primary endpoint was time from skin closure to time to extubation. Aldrete score, White Fast Track score and QoR-40 were also assessed. There was no significant difference in time to extubation [12.5 (SD 7.4)min in the control group versus 13.0 (SD 5.9)min for the treatment group]. The control group used more fentanyl [339 mcg (SD 205)] than did the treatment group [238 mcg (SD 123)] (P<0.02). There was no difference in sevoflurane utilization, Aldrete, White Fast Track scores, time to PACU discharge, or QoR-40 assessments between the groups. Use of the SEDLine™ monitor's data to titrate sevoflurane did not improve the time to extubation or change short-term outcome of geriatric surgical patients receiving beta-adrenergic blockers. (ClinicalTrials.gov number, NCT00938782).