title: Prevention of contrast-induced acute kidney injury: is simple oral hydration similar to intravenous? A systematic review of the evidence.
abstract: BACKGROUND
  Pre-procedural intravenous fluid administration is an effective prophylaxis measure for contrast-induced acute kidney injury. For logistical ease, the oral route is an alternative to the intravenous. The objective of this study was to compare the efficacy of the oral to the intravenous route in prevention of contrast-induced acute kidney injury.
  
  
  METHODS
  A systematic review and meta-analysis of randomised trials with a stratified analysis and metaregression. Databases included MEDLINE (1950 to November 23 2011), EMBASE (1947 to week 47 2011), Cochrane CENTRAL (3(rd) quarter 2011). Two reviewers identified relevant trials and abstracted data. SETTINGS AND POPULATION: Trials including patients undergoing a contrast enhanced procedure.
  
  
  METHODS
  Randomised controlled trial; adult (>18 years) population; comparison of oral versus intravenous volume expansion.
  
  
  METHODS
  Oral route of volume expansion compared to the intravenous route.
  
  
  RESULTS
  Any measure of acute kidney injury, need for renal replacement therapy, hospitalization and death.
  
  
  RESULTS
  Six trials including 513 patients met inclusion criteria. The summary odds ratio was 1.19 (95% CI 0.46, 3.10, p = 0.73) suggesting no difference between the two routes of volume expansion. There was significant heterogeneity (Cochran's Q = 11.65, p = 0.04; I(2) = 57). In the stratified analysis, inclusion of the five studies with a prespecified oral volume expansion protocol resulted in a shift towards oral volume expansion (OR 0.75, 95% CI 0.37, 1.50, p = 0.42) and also resolved the heterogeneity (Q = 3.19, P = 0.53; I(2) = 0).
  
  
  CONCLUSIONS
  Small number of studies identified; lack of hard clinical outcomes.
  
  
  CONCLUSIONS
  The oral route may be as effective as the intravenous route for volume expansion for contrast-induced acute kidney injury prevention. Adequately powered trials with hard endpoints should be done given the potential advantages of oral (e.g. reduced patient burden and cost) over intravenous volume expansion.
authors.affiliation: Division of Nephrology, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada. shiremath@toh.on.ca
authors.forename: Swapnil
authors.initials: S
authors.lastname: Hiremath
authors.forename: Ayub
authors.initials: A
authors.lastname: Akbari
authors.forename: Wael
authors.initials: W
authors.lastname: Shabana
authors.forename: Dean A
authors.initials: DA
authors.lastname: Fergusson
authors.forename: Greg A
authors.initials: GA
authors.lastname: Knoll
mesh_terms: D058186:Acute Kidney Injury / Q000139:chemically induced* / Q000517:prevention & control*; D061605:Administration, Intravenous; D000284:Administration, Oral; D003287:Contrast Media / Q000008:administration & dosage* / Q000009:adverse effects*; D006801:Humans
chemical_list: D003287:Contrast Media
references.citation: Circulation. 2011 Feb 1;123(4):409-16
references.pmid: 21242477
references.citation: Clin J Am Soc Nephrol. 2009 Oct;4(10):1584-92
references.pmid: 19713291
references.citation: BMJ. 1994 Jan 8;308(6921):72-4
references.pmid: 8298415
references.citation: Ann Vasc Surg. 2007 Sep;21(5):593-7
references.pmid: 17823041
references.citation: J Interv Cardiol. 2010 Oct;23(5):460-6
references.pmid: 20796166
references.citation: Nephron Clin Pract. 2003 Jan;93(1):C29-34
references.pmid: 12411756
references.citation: MMWR Recomm Rep. 1992 Oct 16;41(RR-16):1-20
references.pmid: 1435668
references.citation: Nephrol Dial Transplant. 2010 Jan;25(1):107-18
references.pmid: 19812232
references.citation: J Occup Health. 2010;52(4):209-15
references.pmid: 20551583
references.citation: Kidney Int. 2005 Jul;68(1):14-22
references.pmid: 15954892
references.citation: Int J Surg. 2010;8(5):336-41
references.pmid: 20171303
references.citation: Control Clin Trials. 1986 Sep;7(3):177-88
references.pmid: 3802833
references.citation: J Am Coll Cardiol. 2004 Oct 6;44(7):1393-9
references.pmid: 15464318
references.citation: Chest. 1998 Dec;114(6):1570-4
references.pmid: 9872190
references.citation: Ann Intern Med. 2009 Feb 3;150(3):170-7
references.pmid: 19189906
references.citation: Arch Intern Med. 2002 Feb 11;162(3):329-36
references.pmid: 11822926
references.citation: Am J Med. 1997 Nov;103(5):368-75
references.pmid: 9375704
references.citation: Crit Care. 2008;12(4):220
references.pmid: 18671838
references.citation: Control Clin Trials. 1996 Feb;17(1):1-12
references.pmid: 8721797
references.citation: Kardiol Pol. 2010 Sep;68(9):1015-20
references.pmid: 20859892
references.citation: Rev Cardiovasc Med. 2006 Fall;7(4):177-97
references.pmid: 17224862
references.citation: Kidney Int Suppl. 2006 Apr;(100):S3-7
references.pmid: 16612398
references.citation: Radiology. 2010 Jul;256(1):21-8
references.pmid: 20574082
references.citation: JAMA. 2004 May 19;291(19):2328-34
references.pmid: 15150204
references.citation: Am J Kidney Dis. 2002 May;39(5):930-6
references.pmid: 11979336
references.citation: Epidemiology. 2011 Jan;22(1):128; author reply 128
references.pmid: 21150360
references.citation: Am J Med. 1983 Feb;74(2):243-8
references.pmid: 6824004
references.citation: Crit Care. 2007;11(2):R31
references.pmid: 17331245
references.citation: JAMA. 2008 Sep 3;300(9):1038-46
references.pmid: 18768415
references.citation: Am J Cardiol. 2006 Sep 18;98(6A):27K-36K
references.pmid: 16949378
references.citation: BMJ. 1997 Sep 13;315(7109):629-34
references.pmid: 9310563
references.citation: Am J Med. 1989 Jun;86(6 Pt 1):649-52
references.pmid: 2729314
references.citation: Nephrol Dial Transplant. 2006 Aug;21(8):2120-6
references.pmid: 16611682
references.citation: J Gen Intern Med. 2009 Mar;24(3):289-98
references.pmid: 19156472
references.citation: Catheter Cardiovasc Interv. 2001 May;53(1):40-5
references.pmid: 11329216
references.citation: Am J Cardiol. 2006 Sep 18;98(6A):59K-77K
references.pmid: 16949381
references.citation: Clin J Am Soc Nephrol. 2008 Sep;3(5):1274-81
references.pmid: 18463172
references.citation: Bull World Health Organ. 2000;78(10):1246-55
references.pmid: 11100619
references.citation: Eur Radiol. 2011 Dec;21(12):2527-41
references.pmid: 21866433
references.citation: Catheter Cardiovasc Interv. 2009 Nov 1;74(5):728-46
references.pmid: 19830793
references.citation: Am J Kidney Dis. 2010 Jun;55(6):1018-25
references.pmid: 20097462
references.citation: Circulation. 2011 May 10;123(18):2022-60
references.pmid: 21444889
references.citation: Catheter Cardiovasc Interv. 2001 Apr;52(4):409-16
references.pmid: 11285590