title: Acetylcysteine for prevention of contrast nephropathy: meta-analysis.
abstract: BACKGROUND
  Contrast nephropathy is associated with increased in-hospital morbidity and mortality and leads to extension of hospital stay in patients with chronic renal insufficiency. Acetylcysteine seems to be a safe and inexpensive way to reduce contrast nephropathy. We aimed to assess the efficacy of acetylcysteine to prevent contrast nephropathy after administration of radiocontrast media in patients with chronic renal insufficiency.
  
  
  METHODS
  We did a meta-analysis of randomised controlled trials comparing acetylcysteine and hydration with hydration alone for preventing contrast nephropathy in patients with chronic renal insufficiency. The trials were identified through a combined search of the BIOSIS+/RRM, MEDLINE, Web of Science, Current Contents Medizin, and The Cochrane Library Databases. We used incidence of contrast nephropathy 48 h after administration of radiocontrast media as an outcome measure.
  
  
  RESULTS
  Seven trials including 805 patients were eligible according to our inclusion criteria and were analysed. Overall incidence of contrast nephropathy varied between 8% and 28%. Since significant heterogeneity was indicated by the Q statistics (p=0.016) we used a random-effects model to combine the data. Compared with periprocedural hydration alone, administration of acetylcysteine and hydration significantly reduced the relative risk of contrast nephropathy by 56% (0.435 [95% CI 0.215-0.879], p=0.02) in patients with chronic renal insufficiency. Meta-regression revealed no significant relation between the relative risk of contrast nephropathy and the volume of radiocontrast media administered or the degree of chronic renal insufficiency before the procedure.
  
  
  CONCLUSIONS
  Compared with periprocedural hydration alone, acetylcysteine with hydration significantly reduces the risk of contrast nephropathy in patients with chronic renal insufficiency. The relative risk of contrast nephropathy was not related to the amount of radiocontrast media given or to the degree of chronic renal insufficiency before the procedure.
authors.affiliation: Fifth Department of Medicine, University Hospital Mannheim, Mannheim, Germany. rainer.birck@med5.ma.uni-heidelberg.de
authors.forename: Rainer
authors.initials: R
authors.lastname: Birck
authors.forename: Stefan
authors.initials: S
authors.lastname: Krzossok
authors.forename: Florian
authors.initials: F
authors.lastname: Markowetz
authors.forename: Peter
authors.initials: P
authors.lastname: Schnülle
authors.forename: Fokko J
authors.initials: FJ
authors.lastname: van der Woude
authors.forename: Claude
authors.initials: C
authors.lastname: Braun
mesh_terms: D000111:Acetylcysteine / Q000627:therapeutic use*; D058186:Acute Kidney Injury / Q000097:blood / Q000139:chemically induced* / Q000453:epidemiology; D000368:Aged; D003287:Contrast Media / Q000009:adverse effects*; D003545:Cysteine / Q000097:blood; D005260:Female; D006801:Humans; D007676:Kidney Failure, Chronic / Q000453:epidemiology*; D008297:Male; D008875:Middle Aged; D017063:Outcome Assessment, Health Care; D011859:Radiography / Q000009:adverse effects; D016032:Randomized Controlled Trials as Topic
chemical_list: D003287:Contrast Media; D003545:Cysteine; D000111:Acetylcysteine