Comparison between intranasal dexmedetomidine and intranasal ketamine as premedication for procedural sedation in children undergoing MRI: a double-blind, randomized, placebo-controlled trial

Providing anesthesia to children undergoing MRI is challenging. Adequate premedication, administered noninvasively, would make the process smoother. In this study, we compare the efficacy of intranasal dexmedetomidine (DXM) with the intranasal administration of ketamine for procedural sedation in children undergoing MRI. We studied 150 children, between 1 and 10 years of age, divided randomly into three groups (DXM, K, and S). For blinding, every child received the intranasal drugs twice; syringe S1, 60 min before, and syringe S2, 30 min before intravenous (IV) cannulation. For children in group DXM, S1 contained DXM (1 mu g/kg) and S2 was plain saline. Children in group K received saline in S1 and ketamine (5 mg/kg) in S2 whereas children in group S received saline in both S1 and S2. The child's response to drug administration, ease of IV cannulation, the satisfaction of the anesthesiologist and child's parents with the premedication, and the total propofol dose required for the satisfactory conduct of the procedure were compared. We also compared the time to awakening and discharge of the child as well as the occurrence of any side effects with these drugs. Both DXM and ketamine were equally effective as premedication in these patients. Most of the children accepted the intranasal drugs with minimal discomfort; 90.4 % of the anesthesiologists in the DXM group and 82.7 % in the ketamine group were satisfied with the conditions for IV cannulation whereas only 21.3 % were satisfied in the saline group. The total dose of propofol used was less in the study groups. Furthermore, children in group DXM and group K had earlier awakening and discharge than those in group S. DXM and ketamine were equally effective, by the intranasal route, as premedication in children undergoing MRI.