ICU Sedation After Coronary Artery Bypass Graft Surgery: Dexmedetomidine-Based Versus Propofol-Based Sedation Regimens

Objective: To compare dexmedetomidine-based to propofol-based sedation after coronary artery bypass graft (CABG) surgery in the intensive care unit (ICU). Design: Randomized, open label. Setting: Twenty-five centers in the United States and Canada. Participants: Two hundred ninety-five adults undergoing CABG surgery. Interventions: At sternal closure, patients in group A received 1.0 μg/kg of dexmedetomidine over 20 minutes and then 0.2 to 0.7 μg/kg/h to maintain a Ramsay sedation score ≥3 during assisted ventilation and ≥2 after extubation. Patients could be given propofol for additional sedation if necessary; group B patients received propofol-based care according to each investigator's standard practice. Measurements and Main Results: Mean sedation levels were within target ranges in both groups. Mean times to weaning and extubation were similar, although fewer dexmedetomidine patients remained on the ventilator beyond 8 hours. Morphine use was significantly reduced in the dexmedetomidine group. Only 28% of the dexmedetomidine patients required morphine for pain relief while ventilated versus 69% of propofol-based patients (p < 0.001). Propofol patients required 4 times the mean dose of morphine while in the ICU. Mean blood pressure increased initially in both groups, then decreased to 3 mmHg below baseline in dexmedetomidine patients; mean arterial pressure remained at 9 mmHg above baseline in propofol patients. No ventricular tachycardia occurred in the dexmedetomidine-sedated patients compared with 5% of the propofol patients (p = 0.007). Respiratory rates and blood gases were similar. Fewer dexmedetomidine patients received β-blockers (p = 0.014), antiemetics (p = 0.015), nonsteroidal anti-inflammatory drugs (p < 0.001), epinephrine (p = 0.030), or high-dose diuretics (p < 0.001). Conclusion: Dexmedetomidine provided safe and effective sedation for post-CABG surgical patients and significantly reduced the use of analgesics, β-blockers, antiemetics, epinephrine, and diuretics.