Renal effects of dexmedetomidine during coronary artery bypass surgery: a randomized placebo-controlled study

This was a double-blind, randomized, parallel-group study. Patients with normal renal function and scheduled for elective CABG were randomized to placebo or to infusion of dexmedetomidine to achieve a pseudo steady-state plasma concentration of 0.60 ng/ml. The infusion was started after anesthesia induction and continued until 4 h after surgery. The primary endpoint was creatinine clearance. Other variables included urinary creatinine and output, fractional sodium and potassium excretion, urinary potassium, sodium and glucose, serum and urinary osmolality and plasma catecholamine concentrations. The data were analyzed with repeated-measures ANOVA or Cochran-Mantel-Haenszel test.Sixty-six of 87 randomized patients were evaluable for analysis. No significant between-group differences were recorded for any indices of renal function except for a mean 74% increase in urinary output with dexmedetomidine in the first 4 h after insertion of a urinary catheter (p < 0.001). Confidence interval examination revealed that the sample size was large enough for the no-difference statement for creatinine clearance.Use of intravenous dexmedetomidine did not alter renal function in this cohort of relatively low-risk elective CABG patients but was associated with an increase in urinary output.This study was carried out in 1994-1997 and was thus not registered.Perioperative administration of alpha2-adrenergic agonist dexmedetomidine, has been shown to reduce anesthetic requirements, enhance hemodynamic stability and provide sedation during postoperative recovery following coronary artery bypass and other surgery [1-6]. Acute kidney injury (AKI) is a recognized complication of cardiovascular surgery and one associated with high mortality and costs-of-care [7]. The pathogenesis of AKI is multifactorial and involves hemodynamic, inflammatory and nephrotoxic components [7]. It is also known that hemodynamics, sympathetic nervous system activity and renal function are tightly interrelated. S