[Alfentanil combination anesthesia in infants].

In the last few years new narcotic agents with more favourable pharmacokinetic properties have been introduced into clinical practice. Short half-lives and smaller distribution volumes facilitate control of anaesthetic depth and shorten the recovery period. One of these narcotics is alfentanil. This study was performed on the effects of alfentanil when used during anaesthesia in infants under the age of one year. After induction and relaxation alfentanil 20 mcg/kg were given i.v. initially. The same dose was repeated as needed until 15 min. before surgery ended. The patients were ventilated with N2O/O2 (2:1). Muscle relaxation was maintained at 90-95% with vecuronium, monitoring "train of four" twitch response. The effects of alfentanil on airway pressure, pulse and blood pressure were measured during and without muscle relaxation. The time from end of surgery until full recovery was recorded. Percutaneous CO2-tension was measured in the recovery room. There were no clinical problems with induction or recovery. The average time until the infants opened their eyes and started moving was 1.8 min. No significant changes in pulse and blood pressure occurred during surgery. Airway pressure showed minimal increases when muscle relaxation decreased. These data suggest that alfentanil/N2O anaesthesia can be considered as an alternative if halogenated hydrocarbons are rated unsuitable in paediatric anaesthesia.