Rectal thiopental versus an intramuscular cocktail for sedating children before computerized tomography.

The sedative effects of rectal thiopental sodium and an intramuscular cocktail of meperidine hydrochloride, chlorpromazine hydrochloride and promethazine hydrochloride were compared in 72 pediatric patients undergoing computerized tomography (CT). Pediatric patients scheduled were randomly assigned to receive either the i.m. cocktail (2.0 mg/kg of meperidine, 1.0 mg/kg of both chlorpromazine and promethazine) or 25--45 mg/kg of thiopental rectally before scanning. Side effects, and onset, duration and depth of sedation were recorded by 14 unblinded investigators. Clarity of CT scans was rated by two blinded radiologists. Additional doses of sedatives were administered as necessary. Sedation was not achieved in 3% of the thiopental group or in 14+ of the i.m. cocktail group. Additional sedatives were required by eight patients in the thiopental group and by five patients in the cocktail group. The mean time for onset of sedation was 8 minutes with thiopental and 18 minutes with the cocktail. The mean duration of sedation was 7 hours for the cocktail group and 2.75 hours for the 25-mg/kg rectal thiopental group. All scans were diagnostic (acceptable) in the rectal thiopental group, but 14% of those in the i.m. cocktail group were nondiagnostic. Rectal thiopental is an effective alternative to an i.m. cocktail for sedating children before CT scans and may reduce the number of nondiagnostic scans.