title: Midazolam coinduction does not delay discharge after very brief propofol anaesthesia.
abstract: Previous reports have demonstrated synergism of midazolam and propofol for induction of anaesthesia in humans. We tested the hypothesis that in the presence of alfentanil, the combination of midazolam with propofol for a very brief operative procedure would not affect the recovery phase. During pre-oxygenation, 64 outpatients scheduled for dilatation and curettage received placebo, or low-dose midazolam (0.03 mg.kg-1), or high-dose midazolam (0.06 mg.kg-1) iv, in a randomized double-blind manner. They then received alfentanil 10 micrograms.kg-1 iv, followed by titrated doses of propofol iv for induction and maintenance of anaesthesia. Ventilation with 70% N2O in O2 by mask was controlled to achieve a PETCO2 30-40 mmHg. Outcome measures were: propofol dose (induction and maintenance), time until eye-opening to command, and time to discharge-readiness. Propofol induction dose was decreased by increasing doses of midazolam (P = 0.00005). Midazolam delayed time to eye-opening (P = 0.02) but not time to discharge-readiness. This study had an 80% power to detect a 39 min difference in time to discharge-readiness. We conclude that midazolam propofol co-induction in the presence of alfentanil delays eye-opening, but does not delay discharge after anaesthesia.
authors.affiliation: Department of Anaesthesia, University of Calgary, Foothills Hospital, Alberta, Canada.
authors.forename: T
authors.initials: T
authors.lastname: Elwood
authors.forename: S
authors.initials: S
authors.lastname: Huchcroft
authors.forename: C
authors.initials: C
authors.lastname: MacAdams
mesh_terms: D015760:Alfentanil / Q000008:administration & dosage* / Q000494:pharmacology; D000762:Anesthesia Recovery Period; D000769:Anesthesia, Inhalation; D000771:Anesthesia, Intravenous; D002245:Carbon Dioxide / Q000378:metabolism; D004107:Dilatation and Curettage; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D004338:Drug Combinations; D004357:Drug Synergism; D005260:Female; D006801:Humans; D008874:Midazolam / Q000008:administration & dosage* / Q000494:pharmacology; D008875:Middle Aged; D009609:Nitrous Oxide; D010351:Patient Discharge; D010919:Placebos; D015742:Propofol / Q000008:administration & dosage* / Q000494:pharmacology; D014851:Wakefulness / Q000187:drug effects
chemical_list: D004338:Drug Combinations; D010919:Placebos; D002245:Carbon Dioxide; D015760:Alfentanil; D009609:Nitrous Oxide; D008874:Midazolam; D015742:Propofol