Dexmedetomidine to Lessen Intensive Care Unit (ICU) Agitation

"Dexmedetomidine will be administered intravenously as a maintenance infusion of 0.2 to 1.5 mcg/kg/hour, commencing at 0.5 mcg/kg/hour and titrated according to effect, for as long as deemed necessary by the treating physician. Specifically, the study medication may be (as recommended by the manufacturer) continued after extubation, and if discontinued may be restarted at any time up until ICU discharge. The clinician will have the option of using a loading dose of 1.0 mcg/kg IV over 20 minutes, as recommended by the manufacturer.~Bedside nursing staff will adjust drug infusion rates as necessary, in consultation with the treating physician, aiming to achieve a Riker Sedation-Agitation Scale 20 score of 4."

An identical syringe containing only saline with no dexmedetomidine added will be supplied. Initial rate of infusion and subsequent adjustments will be the same as in the active comparator group.