Pain relief for outpatient colonoscopy: a comparison of alfentanil with fentanyl.

Alfentanil was used as an adjuvant to midazolam for analgesia in thirty outpatients undergoing colonoscopy. A similar group of thirty outpatients received fentanyl. The operating conditions and recovery times of the two groups were compared. Alfentanil usage resulted in better operating conditions. Recovery time was similar. Patient acceptance was high. No patient suffered respiratory depression during or after the procedure.