title: Severe acute kidney injury not treated with renal replacement therapy: characteristics and outcome.
abstract: BACKGROUND
  Only a proportion of critically ill patients with severe [RIFLE (Risk, Injury, Failure, Loss, End-stage renal disease) criteria, class-F] acute kidney injury (AKI) appear to receive renal replacement therapy (RRT). The aim of this study was to study the characteristics and outcome of patients with severe (RIFLE-F) AKI who did not receive RRT.
  
  
  METHODS
  We identified all consecutive patients admitted to our institution that developed RIFLE-F AKI by creatinine criteria over a 3-year period and did not receive RRT, and compared their characteristics and outcomes with those of RIFLE-F RRT-treated patients.
  
  
  RESULTS
  Within the study period, 20,126 patients were admitted to our institution for >24 h. Among them, 2949 were admitted to the intensive care unit (ICU) and 195 developed RIFLE-F AKI. Of these, 90 received RRT (RRT patients) and 105 did not (no-RRT patients). Compared with RRT patients, no-RRT patients were similar in terms of age, gender and ward of origin. However, they had a shorter median ICU stay (2.7 versus 7.9 days; P < 0.001), required less mechanical ventilation (56.2 versus 70%; P < 0.05) and had a lower mean Acute Physiology and Chronic Health Evaluation III score (82.7 versus 86.7; P < 0.05). The two main reasons these patients did not receive RRT were limitations of medical therapy (LOMT) orders in 41 (39%) cases and expected renal functional improvement in 59 (56.2%). Mortality in no-RRT patients was 58.1% compared with 55.5% in the RRT group (P = 0.72). After exclusion of LOMT patients, the mortality of the no-RRT group, although lower than that of the RRT group, remained high (30.5 versus 55%; P < 0.001). Most of these deaths occurred after ICU discharge and appeared secondary to underlying chronic diseases or recurrence of the initial insult.
  
  
  CONCLUSIONS
  After exclusion of LOMT patients, about a third of critically ill patients with severe (RIFLE-F) AKI did not receive RRT. A third of these patients died in hospital. The timing of the deaths and their underlying causes do not suggest that a broader application of RRT would have changed patient outcomes.
authors: Department of Intensive Care, Austin Health, Heidelberg, Australia.
authors: Antoine G
authors: AG
authors: Schneider
authors: Shigehiko
authors: S
authors: Uchino
authors: Rinaldo
authors: R
authors: Bellomo
mesh_terms: D058186:Acute Kidney Injury / Q000401:mortality* / Q000628:therapy*; D000368:Aged; D016638:Critical Illness / Q000401:mortality; D005260:Female; D006801:Humans; D007362:Intensive Care Units / Q000706:statistics & numerical data*; D008297:Male; D017582:Renal Replacement Therapy / Q000401:mortality*; D012189:Retrospective Studies; D015996:Survival Rate; D016896:Treatment Outcome