Minimizing ICU Neurological Dysfunction With Dexmedetomidine-induced Sleep

This study aims to determine whether, compared with placebo, the nighttime administration of a intravenous dexmedetomidine is effective at inducing sleep and preventing postoperative delirium in extubated post-cardiac surgical patients.

Inclusion Criteria: * Age ≥ 60 * Scheduled for a cardiac surgical procedure with planned post-operative admission to the CSICU for ≥ 24 hours * Scheduled same day surgical admission Exclusion Criteria: * Blind, deafness or the inability to speak English * Greater than 2 days of ICU admission in the month preceding the current surgical procedure * Renal and liver failure requiring dialysis or Child-Pugh score \> 5 * Follow-up difficulties (i.e. active substance abuse, psychotic disorder, homelessness) * Previous cardiac surgery within 1 year of surgical procedure * Allergy to dexmedetomidine * Chronic therapy with benzodiazepines and/or antipsychotics * Severe deficit due to structural or anoxic brain damage * Surgical procedure requiring total circulatory arrest Objective Drop Criteria * Scheduled for a second surgical procedure during hospital stay * Post-operative intubation \> 12 hours