Uusalo P, et al. - Whether dexmedetomidine (a highly selective α₂-adrenoceptor agonist) would attenuate barbiturate requirements in procedural sedation, was investigated in 200 consecutive pediatric patients undergoing magnetic resonance imaging (MRI). The DEX group comprised half of the patients who were given 3 μg/kg of intranasal (IN) dexmedetomidine 45–60 min before MRI, and the THIO group comprising the rest of the patients who were administered only thiopental for procedural sedation. Further intravenous thiopental dosing was used to maintain sedation. They assessed thiopental consumption, heart rate (HR) and peripheral oxygen saturation. In the DEX group and in the THIO group, the respective cumulative thiopental requirement during MRI was 4.4 (2.7–6.0) mg/kg/h and 12.4 (9.8–14.8) mg/kg/h, respectively. The needed thiopental dosage for efficient procedural sedation for pediatric MRI was significantly attenuated in relation to premedication with IN dexmedetomidine (3 μg/kg).