title: Fluid overload is an independent risk factor for acute kidney injury in critically Ill patients: results of a cohort study.
abstract: BACKGROUND
  Acute Kidney injury (AKI) is common and increases mortality in the intensive care unit (ICU). We carried out this study to explore whether fluid overload is an independent risk factor for AKI.
  
  
  METHODS
  Single-center prospective, observational study. Consecutively admitted, ICU patients were followed for development of AKI. Intravenous fluid volumes, daily fluid balances were measured, hourly urine volumes, daily creatinine levels were recorded.
  
  
  RESULTS
  Three hundred thirty nine patients were included; AKI developed in 141 (41.6%) patients; RISK in 27 (8%) patients; INJURY in 25 (7%); FAILURE in 89 (26%) by the RIFLE criteria. Fluid balance was significantly higher in patients with AKI; 1755 ± 2189 v/s 924 ± 1846 ml, p < 0.001 on ICU day 1. On multivariate regression analysis, a net fluid balance in first 24 h of ICU admission, OR 1.02 (95% CI 1.01,1.03 p = 0.003), percentage of fluid accumulation adjusted for body weight OR1.009 (95% CI 1.001,1.017, p = 0.02), fluid balance in first 24 h of ICU admission with serum creatinine adjusted for fluid balance, OR 1.024 (95% CI 1.012,1,035, p = 0.005), Age, OR 1.02 95% CI 1.01,1.03, p < 0.001, CHF, OR 3.1 (95% CI 1.16,8.32, p = 0.023), vasopressor requirement on ICU day one, OR 1.9 (95% CI 1.13,3.19, p = 0.014) and Colistin OR 2.3 (95% CI 1.3, 4.02, p < 0.001) were significant predictors of AKI. There was no significant association between fluid type; Chloride-liberal, Chloride-restrictive, and AKI.
  
  
  CONCLUSIONS
  Fluid overload is an independent risk factor for AKI.
authors.affiliation: Adult Critical Care Medicine, King Faisal Specialist Hospital & Research Center Riyadh, Riyadh, Saudi Arabia. nsalahuddin@kfshrc.edu.sa.
authors.forename: Nawal
authors.identifier: http://orcid.org/0000-0002-4422-6699
authors.initials: N
authors.lastname: Salahuddin
authors.affiliation: Adult Critical Care Medicine, King Faisal Specialist Hospital & Research Center Riyadh, Riyadh, Saudi Arabia.
authors.forename: Mustafa
authors.initials: M
authors.lastname: Sammani
authors.affiliation: Adult Critical Care Medicine, King Faisal Specialist Hospital & Research Center Riyadh, Riyadh, Saudi Arabia.
authors.forename: Ammar
authors.initials: A
authors.lastname: Hamdan
authors.affiliation: Critical Care, Department of Nursing, King Faisal Specialist Hospital & Research Centre Riyadh, Riyadh, Saudi Arabia.
authors.forename: Mini
authors.initials: M
authors.lastname: Joseph
authors.affiliation: Department of Surgery, King Faisal Specialist Hospital & Research Centre Riyadh, Riyadh, Saudi Arabia.
authors.forename: Yasir
authors.initials: Y
authors.lastname: Al-Nemary
authors.affiliation: Adult Critical Care Medicine, King Faisal Specialist Hospital & Research Center Riyadh, Riyadh, Saudi Arabia.
authors.forename: Rawan
authors.initials: R
authors.lastname: Alquaiz
authors.affiliation: Adult Critical Care Medicine, King Faisal Specialist Hospital & Research Center Riyadh, Riyadh, Saudi Arabia.
authors.forename: Ranim
authors.initials: R
authors.lastname: Dahli
authors.affiliation: Adult Critical Care Medicine, King Faisal Specialist Hospital & Research Center Riyadh, Riyadh, Saudi Arabia.
authors.forename: Khalid
authors.initials: K
authors.lastname: Maghrabi
mesh_terms: D058186:Acute Kidney Injury / Q000401:mortality* / Q000628:therapy*; D017677:Age Distribution; D000368:Aged; D015984:Causality; D015331:Cohort Studies; D015897:Comorbidity; D016638:Critical Illness / Q000401:mortality / Q000628:therapy; D005260:Female; D005440:Fluid Therapy / Q000401:mortality* / Q000706:statistics & numerical data*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D012529:Saudi Arabia / Q000453:epidemiology; D015996:Survival Rate; D016896:Treatment Outcome; D014883:Water-Electrolyte Imbalance / Q000401:mortality* / Q000628:therapy*
keywords: Acute kidney injury; Chloride-liberal fluids; Critical illness; Fluid overload; Renal congestion