title: Clinical factors associated with initiation of renal replacement therapy in critically ill patients with acute kidney injury-a prospective multicenter observational study.
abstract: OBJECTIVE
  Our objective was to describe the current practice for initiation of RRT in this population. There is uncertainty regarding the optimal time to initiate renal replacement therapy (RRT) in critically ill patients with acute kidney injury (AKI).
  
  
  METHODS
  Prospective study of patients receiving RRT in 6 intensive care units (ICUs) at 3 hospitals from July 2007 to August 2008. We characterized factors associated with start of RRT and evaluated their relationship with mortality.
  
  
  RESULTS
  We included 234 patients. RRT was initiated 1 day (0-4) after ICU admission (median [interquartile range]). Median creatinine was 331 μmol/L (225-446 μmol/L), urea 22.9 mmol/L (13.9-32.9 mmol/L), and RIFLE-Failure in 76.9%. Of traditional indications, Pao(2)/Fio(2) < 200 (54.5%) and oliguria (32.9%) were most common. ICU and hospital mortality were 45.3% and 51.9%, respectively. In adjusted analysis, mortality at RRT initiation was associated with creatinine <332 μmol/L (odds ratio [OR] 2.8; 95% confidence interval [CI] 1.5-5.4), change in urea from admission >8.9 mmol/L (OR 1.8; 95% CI, 1.0-3.4), urine output <82 mL/24 hours (OR 3.0; 95% CI, 1.4-6.5), fluid balance >3.0 L/24 hours (OR 2.3; 95% CI, 1.2-4.5), percentage of fluid overload >5% (OR 2.3; 95% CI, 1.2-4.7), 3 or more failing organs (OR 4.5; 95% CI, 1.2-4.2), Sequential Organ Failure Assessment score >14 (OR 2.3; 95% CI, 1.3-4.3), and start 4 days or more after admission (OR 4.3; 95% CI, 1.9-9.5). Mortality was higher as factors accumulated.
  
  
  CONCLUSIONS
  In ICU patients requiring RRT, there was marked variation in factors that influence start of RRT. RRT initiation with fewer clinical triggers was associated with lower mortality. Timing of RRT may modify survival but requires appraisal in a randomized trial.
authors.affiliation: University of Alberta Hospital, Edmonton, Alberta, Canada T6G 2B7. bagshaw@ualberta.ca
authors.forename: Sean M
authors.initials: SM
authors.lastname: Bagshaw
authors.forename: Ron
authors.initials: R
authors.lastname: Wald
authors.forename: Jim
authors.initials: J
authors.lastname: Barton
authors.forename: Karen E A
authors.initials: KE
authors.lastname: Burns
authors.forename: Jan O
authors.initials: JO
authors.lastname: Friedrich
authors.forename: Andrew A
authors.initials: AA
authors.lastname: House
authors.forename: Matthew T
authors.initials: MT
authors.lastname: James
authors.forename: Adeera
authors.initials: A
authors.lastname: Levin
authors.forename: Louise
authors.initials: L
authors.lastname: Moist
authors.forename: Neesh
authors.initials: N
authors.lastname: Pannu
authors.forename: Daniel E
authors.initials: DE
authors.lastname: Stollery
authors.forename: Michael W
authors.initials: MW
authors.lastname: Walsh
mesh_terms: D058186:Acute Kidney Injury / Q000401:mortality / Q000628:therapy*; D002170:Canada / Q000453:epidemiology; D005260:Female; D006305:Health Status Indicators; D017052:Hospital Mortality; D006801:Humans; D007677:Kidney Function Tests; D008297:Male; D008875:Middle Aged; D018579:Patient Selection; D011446:Prospective Studies; D006435:Renal Dialysis / Q000379:methods*; D016019:Survival Analysis