Dexmedetomidine Infusion Versus Oral Melatonin for Prevention of Intensive Care Delirium

Patients will receive an intravenous dexmedetomidine infusion of 0.2 mcg/kg/h starting at 9 p.m. The infusion will be halved at 6:00 A.M. and discontinued at 6:15 A.M.

Patients will receive oral melatonin tablet 3 mg 9:00 p.m.

Patients will receive saline infusion at the same rate of dexmedetomidine infusion and placebo capsule similar to that of melatonin.