Effect of flumazenil on recovery from general anesthesia with isoflurane: A randomized controlled trial

Abstract

Background and objectivesThe inhalational anesthetic isoflurane is widely used in general anesthetics. Its mechanism of action involves interaction with the receptor of gamma-aminobutyric acid (GABA), which is also the binding site for benzodiazepines. Flumazenil, benzodiazepine antagonist, reverses the effects of these drugs in GABA receptors and could therefore also reverse the effect of isoflurane. In anesthesia practice, extubation and early anesthetic recovery reduce morbidity and incidence of complications. The objective of this trial is to determine whether the use of flumazenil may contribute to faster recovery from anesthesia. MethodsForty patients scheduled to undergo general anesthesia with isoflurane were enrolled in this prospective, double-blind, randomized trial. Patients were randomized to receive, at the end of anesthesia, flumazenil or placebo as allocated into two groups. The anesthetic technique was standardized. The groups were compared concerning values of cerebral state index (CSI), heart rate, blood pressure and oxygen saturation from the application of flumazenil or placebo until 30min after injection. Data regarding time to extubation, time to reach 10 points in the Aldrete–Kroulic score (AK=10) and Vigilance score (VS=10) was also collected. ANOVA test was applied to analyze the results, considering p<0.05. ResultsPatients receiving flumazenil achieved faster extubation than the control (p=0.033). No differences were observed in values of CSI, the time until AK=10 and until VS=10. ConclusionsAdministration of flumazenil at the end of isoflurane general anesthesia resulted in earlier extubation in studied patients.