The Bolus Dose of Dexmedetomidine (ED50) That Avoids Hemodynamic Compromise in Children

The bolus dose of dexmedetomidine given will range from 0.25-2.0 mcg/kg and will be based on the up-and-down method, such that subject 1 will receive 0.5 mcg/kg and if no significant hemodynamic changes occur (heart rate decrease \< 20% or blood pressure decrease/increase \< 20%) the does will be increased by 0.25 mcg/kg for the subsequent subject. If significant hemodynamic changes occur (HR decrease \>/= 20% or SBP/DBP/MAP decrease or increase \>/= 20%) the dose will be decreased by 0.25 mcg/kg for the subsequent subject. Each subject will be observed for 10 minutes following the dexmedetomidine bolus.