[Sedation of a pediatric patient using dexmedetomidine for day-care MRI]

We report the use of dexmedetomidine for sedation in a 4-year-old boy with a history of bronchial asthma for day-care MRI. Diazepam and atropine sulfate were administrated orally as premedication. In the recovery room, 0.7 microg x kg(-1) x h(-1) of dexmedetomidine was administered intravenously after a bolus infusion 6.0 microg x kg(-1) x h(-1) for 10 min. In the MRI room, a disposable pump was used as an infusion device. The MRI examination was completed in 30 min, and administration of dexmedetomidine was terminated. No body movement or respiratory disorders were seen during the MRI. Sixty min after the termination of dexmedetomidine administration, the Ramsay score had temporarily recovered to 2, but he was drowsy. He was fully awake 210 min after termination of dexmedetomidine administration. Nausea after swallowing water and stagger while walking were not noted. Subsequently, he went home. It is felt that dexmedetomidine is suitable for sedation during MRI examination because it has little effect on respiration. However, the vital sings must be carefully observed during and after the administration of dexmedetomidine because information on its usefulness for pediatric patients or/and day-care are inadequate and infusion rate of disposable pump varies depending on environmental temperature or consistency of drugs.