Total intravenous anaesthesia with midazolam and flumazenil in outpatient clinics

Abstract
Total intravenous anaesthesia with midazolam and alfentanil, reversed with the benzodiazepine antagonist flumazenil, was studied in patients admitted for outpatient gynaecological dilatation and curettage. One hundred patients were randomly allocated to four groups with different anaesthetic techniques: I: alfentanil and thiopentone induction, 66% N2O maintenance; II: alfentanil and midazolam sedation prior to isoflurane and N2O induction and maintenance; III: midazolam and alfentanil induction; oxygen/air, placebo reversal; IV: midazolam and alfentanil induction, oxygen/air, flumazenil reversal. All methods of anaesthesia proved satisfactory with no serious side‐effects or complications. Induction was faster in Group I (26 s) compared with Group III and IV (37–38 s) and Group I (62 s). Respiration was less depressed in Group II compared with the other groups. Recovery function was better in Group IV during the first 30 postoperative min and worse in Group III during the first 120 postoperative min compared with the other groups. Reduced performances in P‐deletion and 4‐choice reaction‐time tests in the midazolam patients were not reversed by 0.5 mg flumazenil, suggesting that flumazenil did not antagonize all benzodiazepine effects in our patients. Postoperative amnesia was most pronounced in Group III. There was no significant difference in patient function 7 h postoperatively, at home in the evening or during the next days. We conclude that total intravenous anaesthesia with alfentanil and midazolam with flumazenil reversal is a promising technique for short outpatient anaesthetic procedures.