Effectiveness of flumazenil on return of cognitive functions after a general anesthetic

Benzodiazepines used intra-operatively can occasionally cause prolonged sedation. Flumazenil (Romazicon) is an imidazobenzodiazepine that functions as a benzodiazepine receptor antagonist. This clinical investigation was designed to evaluate the efficacy and of intravenous flumazenil in reversing the central effects of midazolam after a general anesthetic using midazolam for maintenance. 30 ASA I-III inpatients entered and completed this study. All were interviewed preoperatively and baseline performance on a battery of psychomotor tests was obtained. Parameters measured included an assessment of sleep status, vital signs, responsiveness to verbal stimuli, quality of speech, facial expression, eye coordination, recognition of a picture card, finger-finger-to-nose (FFN) coordination and overall discharge readiness. General anesthesia was induced with midazolam. Midazolam and fentanyl were the primary maintenance agents combined with N2O and O2 (70:30) and a limited concentration of isoflurane. In the recovery room the test drug was administered in a double-blinded, randomized manner. 20 patients received flumazenil (F), the rest placebo (P). Testing was done at times 0, 5, 15, 30, 60, 120, and 180 min in the PACU. Memory testing consisted of recall of study pictures at 180 min and recognition on the first postoperative day. Demographic data were similar for both groups with the exception of age. The F group had a higher mean composite score (comprising responsiveness to verbal stimuli, speech, facial expression and eye coordination) and better FFN scores at 5, 15, and 30 min (p < 0.01). There were no significant differences between groups at other times. F patients identified pictures better at 5 and 15 min (p < 0.004 and 0.04).(ABSTRACT TRUNCATED AT 250 WORDS)