Efficacy and safety of rectal thiopental, intramuscular cocktail and rectal midazolam for sedation in children undergoing neuroimaging

Background : This study was designed to investigate the overall usefulness of rectal thiopental, rectal midazolam and i.m. modified cocktail (meperidine-chlorpromazine hydrochloride-feniramin maleat) in 70 children undergoing computed tomography (CT) and magnetic resonance imaging (MRI). Methods : The dosage of thiopental was 50 mg per kg for infants under 6 months of age, 35 mg per kg between six and 12 months, and 25 mg per kg for older children. The maximal dose did not exceed 700 mg in this study. The dosage of midazolam was 1 mg per kg for all children. A modified cocktail was described as a formulation including 11 mg/mL of meperidine, 2.8 mg/mL of chlorpromazine and 2.8 mg/mL of pheniramine maleat. The dosage of modified cocktail was 0.1 mL per kg for all children. Results : The mean induction time for the i.m. cocktail was significantly longer than that for rectal thiopental (P<0.001). The mean duration of deep sedation was 60.79±27.00 min with rectal thiopental and 58.74±39.70 min with i.m. cocktail (P>0.05). Although the mean duration of sleep for rectal thiopental and i.m. cocktail was similar, the mean discharge duration for i.m. cocktail was significantly longer than that for rectal thiopental (P<0.05). Children sedated with the cocktail therapy also required a longer period of observation in the department. Significant decreases in heart rate, systolic blood pressure and oxygen saturation occurred in three groups (P<0.001). Significant decreases in body temperature occurred after rectal thiopental and i.m. cocktail therapy (P<0.01). The effect of rectal midazolam was minimal. Conclusions : Rectal thiopental may be the drug of choice for pediatric sedation because it has a more rapid onset and offset of action. It is also safe and effective at the dosage studied in children undergoing MRI. Rectal midazolam also may be used in children undergoing CT imaging because of minimal side-effects.