Patients identified by selection criteria within 48 hours of intubation will be randomly assigned to one of three study arms: dexmedetomidine 0.2 mcg/kg/hr, dexmedetomidine 0.6 mcg/kg/hr, or placebo. If not already on, patients will be converted to propofol and fentanyl for sedation and analgesia, which will be titrated to a goal SAS score of 3-4.~Patients will be monitored, assessed, and evaluated by all regular policies and procedures of the institution. Extubation will be at the discretion of the physicians and medical team caring for the patient. If the patient is still intubated at five days study drug will then be stopped and further use of dexmedetomidine will be at the discretion of the physicians.~Primary objective will assess impact of increasing dose of dexmedetomidine on total daily dose of fentanyl and propofol while maintaining sedation in a mechanically ventilated patient in a general medical intensive care unit.~Secondary objectives include total ventilation time, ICU length of stay, hospital length of stay, patient outcomes/mortality, and total pharmacy expenditures.
Assess impact of increasing dose of dexmedetomidine on total daily dose of fentanyl and propofol while maintaining sedation in a mechanically ventilated patient in a general medical intensive care unit.