Similar recovery from bispectral index-titrated isoflurane and sevoflurane anesthesia after outpatient gynecological surgery

Abstract Study Objective To test the hypothesis that the recovery of gynecological day-case patients is equally fast after isoflurane and sevoflurane anesthesia, when administration of the inhaled agent is adjusted by monitoring the bispectral index (BIS). Design Prospective, randomized, controlled, single-blinded clinical study. Setting University-affiliated women's hospital. Patients 120 adult female patients, ASA physical status I or II, scheduled for ambulatory surgery under general anesthesia. Interventions Patients were randomized to receive either isoflurane or sevoflurane as the maintenance anesthetic. BIS values were titrated to remain between 50 and 60 during the maintenance of anesthesia by adjusting the inspired concentration of the inhaled agent. Administration of the inhaled agent was discontinued abruptly at the end of the procedure. Measurements The times to achieving several recovery end points were recorded. The main outcome parameter was the time to home-readiness. In the postoperative care unit, sedation was evaluated with the digit-symbol substitution test. The degree of pain and nausea was evaluated on the visual analog scale. Main results There were no statistically significant differences in the times to home-readiness, or in any other parameters of early or intermediate recovery between the 2 groups. The degrees of sedation, pain, and nausea in the postoperative care unit were similar in the 2 groups. Conclusions Isoflurane and sevoflurane are equally acceptable maintenance anesthetics in terms of the speed and quality of recovery in gynecological ambulatory surgery patients when the dose of the inhaled agent is adjusted to achieve a BIS between 50 and 60.