title: Prevention of radiocontrast nephropathy with N-acetylcysteine in patients with chronic kidney disease: a meta-analysis of randomized, controlled trials.
abstract: BACKGROUND
  Radiocontrast nephropathy (RCN) is a common cause of hospital-acquired acute renal failure. Results of several studies using N-acetylcysteine (NAC) for the prevention of RCN have yielded conflicting results. We performed a meta-analysis of group data extracted from previously published studies to assess the effect of NAC on the prevention of RCN in patients with pre-existing chronic kidney disease (CKD).
  
  
  METHODS
  Ovid's multidatabase search for MEDLINE, Cochrane Central Registry of Controlled Trials, Cochrane Database of Systematic Reviews, and HealthSTAR were used to identify candidate articles. Abstracts from proceedings of scientific meetings also were screened. We selected blinded and unblinded randomized controlled trials (RCTs) performed in humans 18 years and older with pre-existing CKD, defined by a mean baseline serum creatinine level of 1.2 mg/dL or greater (> or =106.1 micromol/L) or creatinine clearance less than 70 mL/min (<1.17 mL/s). The overall risk ratio (RR) for the development of RCN was computed using a random-effects model.
  
  
  RESULTS
  Eight RCTs (n = 885 patients) published in full-text articles were included in the primary analysis. In the control group, the overall rate of RCN was 18.5% (95% confidence interval [CI], 15 to 22). In the primary analysis, overall RR for RCN associated with the use of NAC was 0.41 (95% CI, 0.22 to 0.79; P = 0.007). In a sensitivity analysis that included 4 additional RCTs published in abstract form, RR remained significant at 0.55 (95% CI, 0.34 to 0.91; P = 0.020).
  
  
  CONCLUSIONS
  NAC reduces the risk for RCN in patients with CKD.
authors.affiliation: Department of Medicine, Division of Nephrology, Tufts-New England Medical Center, Boston, MA 02111, USA.
authors.forename: Alvaro
authors.initials: A
authors.lastname: Alonso
authors.forename: Joseph
authors.initials: J
authors.lastname: Lau
authors.forename: Bertrand L
authors.initials: BL
authors.lastname: Jaber
authors.forename: Andrew
authors.initials: A
authors.lastname: Weintraub
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Sarnak
mesh_terms: D000111:Acetylcysteine / Q000627:therapeutic use*; D058186:Acute Kidney Injury / Q000139:chemically induced / Q000517:prevention & control*; D006328:Cardiac Catheterization / Q000009:adverse effects; D003287:Contrast Media / Q000009:adverse effects*; D003553:Cystine / Q000031:analogs & derivatives* / Q000627:therapeutic use; D016166:Free Radical Scavengers / Q000627:therapeutic use*; D006801:Humans; D007676:Kidney Failure, Chronic / Q000150:complications; D016032:Randomized Controlled Trials as Topic; D014057:Tomography, X-Ray Computed / Q000009:adverse effects
chemical_list: D003287:Contrast Media; D016166:Free Radical Scavengers; D003553:Cystine; D000111:Acetylcysteine; C030905:N-monoacetylcystine