Organ dysfunction after cardiac surgery may be reduced by dexmedetomidine. We evaluated whether perioperative dexmedetomidine reduces complications after cardiac surgery with cardiopulmonary bypass.

In this randomised, double-blind, placebo-controlled trial conducted in nine Chinese hospitals, adults scheduled for cardiac surgery with cardiopulmonary bypass were randomly assigned to receive i.v. dexmedetomidine (0.4 μg kg⁻¹ h⁻¹) or saline (placebo) for 12 h after the induction of anaesthesia. The co-primary outcomes were in-hospital mortality and major complications after surgery (including stroke, myocardial infarction, heart block, cardiac arrest), analysed by intention-to-treat. Secondary outcomes included individual complications.

A total of 1073 participants (46% female; mean age: 54 yr [range: 47−63 yr]) completed the study after randomisation. Major complications occurred in 161/536 (30%) participants who received dexmedetomidine, compared with 169/537 (32%) who received saline (relative risk: 0.93 [95% confidence interval: 0.72–1.21]; P=0.66). In addition, 10/536 (1.9%) participants who received dexmedetomidine died in hospital, compared with 15/537 (2.8%) participants who received saline (odds ratio: 0.66 [95% confidence interval: 0.29–1.49]; P=0.32). Major complications, other than heart block, did not differ between participants who received dexmedetomidine, compared with participants who received saline. Safety outcomes and process measures did not differ between participants allocated to dexmedetomidine or saline.

Perioperative use of dexmedetomidine did not reduce death, complications, or both in adults undergoing cardiopulmonary bypass-assisted cardiac surgery.