 The investigators believe dexmedetomidine will provide superior sedation with reduced side effects and reduced time to discharge compared with pentobarbital. The investigators have developed sedation protocols with pentobarbital and dexmedetomidine in our ambulatory procedure center. These protocols are both routinely used for sedation in our unit. The investigators propose to study these two protocols in children ages 6 months to 6 years presenting to the ambulatory procedure center for non-painful procedural sedation. The investigators will compare failure of sedation, side effect profile, recovery and discharge times between the two pharmacologic protocols. 