N-acetylcysteine in cardiovascular-surgery-associated renal failure: a meta-analysis.

BACKGROUND Clinical trials with N-acetylcysteine (NAC) in perioperative cardiovascular settings have shown inconsistent effects for renal endpoints. We aimed to systematically review these trials to ascertain its role in prevention of post-cardiovascular surgery acute renal failure. METHODS We searched MEDLINE, EMBASE, Cochrane Renal Health Library, and Google Scholar for randomized controlled studies that evaluated NAC in adult patients undergoing cardiovascular surgery. Acute renal failure, acute renal failure requiring dialysis, and mortality were the primary outcomes. Additional outcomes studied were length of intensive care unit stay, postoperative serum creatinine, creatinine clearance, renal biomarkers, and adverse effects of NAC. RESULTS Twelve studies comprising 1,324 patients were found to be eligible. Meta-analytic estimates showed that NAC was not associated with reduction in acute renal failure (odds ratio [OR]: 0.89, 95% confidence interval [CI]: 0.68 to 1.15), acute renal failure requiring dialysis (OR: 1.09, 95% CI: 0.57 to 2.09) or mortality (OR: 0.95, 95% CI: 0.53 to 1.71). N-acetylcysteine was well tolerated but was not associated with any reduction in the length of intensive care unit stay. It had inconsistent effects on postoperative serum creatinine, creatinine clearance, and renal biomarkers. Subgroup analysis restricted to studies using intravenous NAC preparation showed a nonsignificant trend toward reduction in acute renal failure (OR: 0.81, 95% CI: 0.61 to 1.08) without any significant change in other outcomes. CONCLUSIONS Overall analysis of the existent literature shows that NAC is not beneficial in the prevention of post-cardiovascular surgery renal dysfunction. Routine use of NAC for this indication should be avoided.