Comparison of Dexmedetomidine versus Propofol for Sedation in Mechanically Ventilated Patients after Cardiovascular Surgery

Many cardiovascular surgeries are fast-tracked to extubation and require short-term sedation. Dexmedetomidine and propofol have very different mechanisms of action and pharmacokinetic profiles that make them attractive sedative agents in this patient population. Recently, there has been increased use of dexmedetomidine in the intensive care unit (ICU), but few studies exist or have been published directly comparing both agents in this setting. We conducted a retrospective cohort study with patients admitted to the ICU after cardiovascular surgery from January through June 2011. Adult patients who underwent coronary artery bypass and/or cardiac valve surgery received either dexmedetomidine or propofol continuous infusion for short-term sedation after cardiovascular surgery. The primary end point was time (hours) on mechanical ventilation after surgery. Secondary end points included ICU length of stay (LOS), hospital LOS, incidence of delirium, and requirement of a second sedative agent. A total of 352 patients met study inclusion criteria, with 33 enrolled in the dexmedetomidine group and 319 in the propofol group. Time on mechanical ventilation was shorter in the dexmedetomidine group (7.4 hours vs. 12.9 hours, P = .042). No difference was seen in ICU or hospital LOS. The need for a second sedative agent to achieve optimal sedation (24% vs. 27%, P = .737) and incidence of delirium (9% vs. 7.5%, P = .747) were similar between both groups. Sedation with dexmedetomidine resulted in a significant reduction in time on mechanical ventilation. However, no difference was seen in ICU or hospital LOS, incidence of delirium, or mortality.