This will be a prospective double-blinded randomized placebo-controlled study. Patients admitted to the ICU and consented for the study will be started on either Naloxone continuous infusion of 0.25micrograms/kilogram/hour (mcg/kg/hr) or normal saline continuous infusion at equal rate and volume to be determined by the pharmacy. The dose or rate of Naloxone infusion will not be manipulated throughout the study.