Alfentanil analgesia for surgical procedures of medium and long duration.

The clinical potential of alfentanil, a short acting narcotic analgesic as a supplement to only nitrous oxide/oxygen was evaluated in 141 patients having surgery of medium and long duration. Following induction of anesthesia with thiopentone alfentanil 1 mg was injected just prior to intubation. Anesthesia was maintained with a mixture of nitrous oxide/oxygen, (2:1) with analgesia achieved by a loading dose of alfentanil 0.1 mg/kg slowly given over 5 to 10 minute period prior to surgery. Additional increments (10-15 micrograms/kg) were given when the expected length of the operation was more than 30 minutes. The course of anesthesia was rated good in 96.4% of the patients. Cardiovascular stability was a feature in almost all patients. Stress responses due to severe surgical stimuli were almost immediately abolished by the administration of small increments of alfentanil (0.5-1 mg). Recovery was extremely rapid and without side-effects. Reversal of respiratory depression was rarely needed.