Double-blinded, randomized controlled trial of N-acetylcysteine for prevention of acute kidney injury in high risk patients undergoing off-pump coronary artery bypass

AimThe aim of this study was to investigate the influence of perioperative N-acetylcysteine (NAC) administration, a known antioxidant, on the incidence of acute kidney injury (AKI) after off-pump coronary bypass surgery (OPCAB) in patients with known risk factors of AKI. MethodsOne hundred and seventeen patients with 1 of the following risk factors of AKI were randomized into either the control (n=57) or the NAC (n=60) group; (i) preoperative serum creatinine >1.4mg/dL; (ii) left ventricular ejection fraction <35% or congestive heart failure (iii) age >70 years (iv) diabetes or (v) re-operation. Patients in the NAC group received 150mg/kg of NAC IV bolus at anaesthetic induction followed by a continuous infusion at 150mg/kg per day for 24h. AKI was diagnosed based on Acute Kidney Injury Network criteria during 48h postoperatively. ResultsThe incidence of AKI was 32% (19/60) and 35% (20/57) in the control and the NAC group, respectively (P=0.695). The serum concentrations of creatinine and cystatin C were similar between the groups throughout the study period. Fluid balance including the amount of blood loss and transfusion requirement were similar between the groups except the amount of postoperative urine output, which was higher in the control group compared with the NAC group (55281247mL vs. 49821185mL, control vs. NAC, P=0.017). ConclusionPerioperative administration of NAC did not prevent the development of postoperative AKI after OPCAB in highly susceptible patients to AKI. Summary at a Glance This manuscript describes whether N-acetylcysteine (NAC) could prevent AKI in high risk patients undergoing off-pump coronary artery bypass (OPCAB). Although high dose NAC did not prevent the development of postoperative AKI, it might be informative because only a few randomized control studies have been reported so far.