Effect of Dexmedetomidine on Postoperative Renal Function in Patients Undergoing Cardiac Valve Surgery Under Cardiopulmonary Bypass: A Randomized Clinical Trial

Objective: The effect of dexmedetomidine on postoperative renal function was investigated in patients undergoing cardiac valve surgery under cardiopulmonary bypass (CPB). Design: A randomized controlled trial. Setting: University teaching, grade A tertiary hospital. Participants: A total of 70 patients scheduled to undergo cardiac valve replacement or valvuloplasty under CPB were eligible and randomly divided into groups D (n = 35) and C (n = 35) between January 2020 and March 2021. Interventions: Patients in group D were administered 0.6 mg/kg/h of dexmedetomidine intravenously from 10 minutes before anesthesia induc-tion to 6 hours after surgery; normal saline was used instead of dexmedetomidine in group C. Measurements and Main Results: The primary outcome was the incidence of acute kidney injury (AKI). Acute kidney injury was defined according to the Kidney Disease Improving Global Outcomes (2012). It was 22.86% and 48.57% in groups D and C, respectively (p = 0.025). The secondary outcomes were intraoperative hemodynamics and various indices in serum. Ten minutes before CPB (T-1), 10 minutes after CPB (T-2), and 30 minutes after CPB (T-3), mean arterial pressure in group D was lower than that in group C, with statistical significance (74.94 +/- 8.52 v 81.89 +/- 13.66 mmHg, p=0.013; 62.83 +/- 11.27 v 71.86 +/- 7.89 mmHg, p < 0.001; 72.26 +/- 8.75 v 78.57 +/- 8.83 mmHg, p = 0.004). At T-1, the heart rate in group D was significantly lower than in group C (80.89 +/- 14.04 v 95.54 +/- 12.53 bpm, p=0.022). The tumor necrosis factor a, inter-leukin-6, C-reactive protein, and cystatin C levels in group D were lower than those in group C after the surgery (T-4) and 24 hours after surgery(T-5), with statistical significance. The duration of mechanical ventilation, intensive-care-unit stay time, and hospital stay time in group D were significantly shorter than in group C. The incidences of tachycardia, hypertension, nausea, and vomiting in group D were similar to those in group C. Conclusions: Dexmedetomidine may be considered as a way to reduce the incidence and severity of postoperative AKI in patients undergoing cardiac valve surgery under cardiopulmonary bypass. (c) 2023 Elsevier Inc. All rights reserved.