Effect of dexmedetomidine on acute kidney injury after aortic surgery: a single-centre, placebo-controlled, randomised controlled trial.

ABSTRACT

BACKGROUND: Acute kidney injury (AKI) is a frequent and serious complication after aortic surgery requiring cardiopulmonary bypass (CPB). Dexmedetomidine, a selective α-2 adrenoreceptor agonist, may reduce AKI because of its sympatholytic and anti-inflammatory effects against ischaemia-reperfusion injury. We investigated the effect of dexmedetomidine administration on AKI after aortic surgery requiring CPB in a placebo-controlled randomised controlled trial. METHODS: A total of 108 patients were randomly assigned to an infusion of dexmedetomidine or saline at a rate of 0.4 µg kg-1 h-1 for 24 h starting after anaesthetic induction. The primary outcome was the incidence of AKI, as defined by the Kidney Disease Improving Global Outcomes (KDIGO) criteria. The secondary outcomes included delirium and major morbidity. Safety outcomes were drug-related adverse events (bradycardia, hypotension). RESULTS: AKI occurred in 7/54 (13%) subjects randomised to dexmedetomidine, compared with 17/54 (31%) subjects randomised to saline infusion (odds ratio=0.32; 95% confidence interval [CI], 0.12-0.86; P=0.026). Secondary outcomes, including stroke, mortality, and delirium, were similar between subjects randomised to dexmedetomidine (16/54 [30%] or saline control (22 [41%]; odds ratio=0.61 [95% CI, 0.28-1.36]). The incidence of bradycardia and hypotension was similar between groups (14/54 (26%) vs. 17/54 (32%) (odds ratio0.76 (95%CI0.33-1.76) and 29/54 (54%) vs. 36/54 (67%) (odds ratio0.58 (95%CI0.27-1.26), respectively). The length of hospital stay was shorter in the dexmedetomidine group (12 [10-17] days) vs saline control (15 [11-21] days; P=0.039). CONCLUSIONS: Pre-emptive dexmedetomidine administration for 24 h starting after induction of anaesthesia reduced the incidence of AKI after aortic surgery requiring CPB, without any untoward side-effects related to its sedative or sympatholytic effects. CLINICAL TRIAL REGISTRATION NCT02607163 (www.ClinicalTrials.gov).