Dexmedetomidine versus Propofol Sedation Reduces Delirium after Cardiac Surgery: A Randomized Controlled Trial

Postoperative delirium (POD) is a serious complication after cardiac surgery. Use of dexmedetomidine to prevent delirium is controversial. The authors hypothesized that dexmedetomidine sedation after cardiac surgery would reduce the incidence of POD.

After institutional ethics review board approval, and informed consent, a single-blinded, prospective, randomized controlled trial was conducted in patients 60 yr or older undergoing cardiac surgery. Patients with a history of serious mental illness, delirium, and severe dementia were excluded. Upon admission to intensive care unit (ICU), patients received either dexmedetomidine (0.4 μg/kg bolus followed by 0.2 to 0.7 μg kg h infusion) or propofol (25 to 50 μg kg min infusion) according to a computer-generated randomization code in blocks of four. Assessment of delirium was performed with confusion assessment method for ICU or confusion assessment method after discharge from ICU at 12-h intervals during the 5 postoperative days. Primary outcome was the incidence of POD.

POD was present in 16 of 91 (17.5%) and 29 of 92 (31.5%) patients in dexmedetomidine and propofol groups, respectively (odds ratio, 0.46; 95% CI, 0.23 to 0.92; P = 0.028). Median onset of POD was on postoperative day 2 (1 to 4 days) versus 1 (1 to 4 days), P = 0.027, and duration of POD 2 days (1 to 4 days) versus 3 days (1 to 5 days), P = 0.04, in dexmedetomidine and propofol groups, respectively.

When compared with propofol, dexmedetomidine sedation reduced incidence, delayed onset, and shortened duration of POD in elderly patients after cardiac surgery. The absolute risk reduction for POD was 14%, with a number needed to treat of 7.1.