title: N-acetylcysteine in cardiac surgery: do the benefits outweigh the risks? A meta-analytic reappraisal.
abstract: OBJECTIVE
  N-acetylcysteine (NAC) reduces proinflammatory cytokines, oxygen free-radical production, and ameliorates ischemia reperfusion injury; therefore, it may theoretically reduce postoperative complications in cardiac surgery. The aim of this study was to determine, through systematic review and meta-analysis of all relevant randomized trials, whether NAC reduces mortality, morbidity, or resource utilization in cardiac surgery.
  
  
  METHODS
  Meta-analysis.
  
  
  METHODS
  University hospitals.
  
  
  METHODS
  A total of 1,407 patients from 15 randomized studies were included in the analysis.
  
  
  METHODS
  None.
  
  
  RESULTS
  All randomized trials searched up to May 2009 comparing the use of NAC versus placebo during cardiac surgery in any language and reporting at least 1 predefined outcome were included. The random effect model was used to calculate odds ratios (ORs, 95% confidence intervals [CIs]) and weighted mean differences (WMD, 95% CI) for dichotomous and continuous variables, respectively. During cardiac surgery, the use of NAC did not significantly decrease acute renal failure requiring renal replacement therapy (OR = 1.05; 95% CI, 0.52-2.11; p = 0.90), new atrial fibrillation (OR = 0.67; 95% CI, 0.37-1.22; p = 0.19), or mortality (OR = 0.81; 95% CI, 0.39-1.68; p = 0.57). There were no differences in the incidence of incremental increase in serum creatinine concentration greater than 25% above baseline (OR = 0.86; 95% CI, 0.66-1.12; p = 0.26), acute myocardial infarction (OR = 0.69; 95% CI, 0.29-1.61, p =0.39), stroke (OR = 0.78; 95% CI, 0.30-2.03; p = 0.61), red blood cell transfusion requirement (OR = 0.77; 95% CI, 0.45-1.31; p = 0.33), re-exploration (OR = 1.33; 95% CI, 0.70-2.26; p = 0.29), or postoperative drainage (WMD = 33 mL; 95% CI,-125 to 191 mL; p = 0.69) between NAC and placebo.
  
  
  CONCLUSIONS
  Current evidence shows that the perioperative use of NAC has no proven benefit or risk on clinically important outcomes in patients undergoing cardiac surgery.
authors.affiliation: Department of Anesthesiology, Cardiovascular Institute and Fuwai Hospital, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing, China. guyanwang@tom.com
authors.forename: Guyan
authors.initials: G
authors.lastname: Wang
authors.forename: Daniel
authors.initials: D
authors.lastname: Bainbridge
authors.forename: Janet
authors.initials: J
authors.lastname: Martin
authors.forename: Davy
authors.initials: D
authors.lastname: Cheng
mesh_terms: D000111:Acetylcysteine / Q000009:adverse effects / Q000627:therapeutic use*; D006348:Cardiac Surgical Procedures / Q000009:adverse effects*; D016166:Free Radical Scavengers / Q000009:adverse effects / Q000627:therapeutic use; D006801:Humans; D011183:Postoperative Complications / Q000188:drug therapy / Q000209:etiology / Q000517:prevention & control*; D016032:Randomized Controlled Trials as Topic / Q000379:methods; D018570:Risk Assessment / Q000379:methods; D012307:Risk Factors
chemical_list: D016166:Free Radical Scavengers; D000111:Acetylcysteine