Long-term outcome in ICU patients with acute kidney injury treated with renal replacement therapy: a prospective cohort study

Crit Care. 2016 Aug 12;20(1):256. doi: 10.1186/s13054-016-1409-z.


Background: In intensive care unit (ICU) patients, acute kidney injury treated with renal replacement therapy (AKI-RRT) is associated with adverse outcomes. The aim of this study was to evaluate variables associated with long-term survival and kidney outcome and to assess the composite endpoint major adverse kidney events (MAKE; defined as death, incomplete kidney recovery, or development of end-stage renal disease treated with RRT) in a cohort of ICU patients with AKI-RRT.

Methods: We conducted a single-center, prospective observational study in a 50-bed ICU tertiary care hospital. During the study period from August 2004 through December 2012, all consecutive adult patients with AKI-RRT were included. Data were prospectively recorded during the patients' hospital stay and were retrieved from the hospital databases. Data on long-term follow-up were gathered during follow-up consultation or, in the absence of this, by consulting the general physician.

Results: AKI-RRT was reported in 1292 of 23,665 first ICU admissions (5.5 %). Mortality increased from 59.7 % at hospital discharge to 72.1 % at 3 years. A Cox proportional hazards model demonstrated an association of increasing age, severity of illness, and continuous RRT with long-term mortality. Among hospital survivors with reference creatinine measurements, 1-year renal recovery was complete in 48.4 % and incomplete in 32.6 %. Dialysis dependence was reported in 19.0 % and was associated with age, diabetes, chronic kidney disease (CKD), and oliguria at the time of initiation of RRT. MAKE increased from 83.1 % at hospital discharge to 93.7 % at 3 years. Multivariate regression analysis showed no association of classical determinants of outcome (preexisting CKD, timing of initiation of RRT, and RRT modality) with MAKE at 1 year.

Conclusions: Our study demonstrates poor long-term survival after AKI-RRT that was determined mainly by severity of illness and RRT modality at initiation of RRT. Renal recovery is limited, especially in patients with acute-on-chronic kidney disease, making nephrological follow-up imperative. MAKE is associated mainly with variables determining mortality.

Keywords: Acute kidney injury (AKI); Acute-on-chronic kidney failure; Long-term survival; Major adverse kidney events (MAKE); Modality of renal replacement therapy; Renal recovery; Renal replacement therapy (RRT); Timing of renal replacement therapy.

Publication types

  • Observational Study

MeSH terms

  • Acute Kidney Injury / mortality
  • Acute Kidney Injury / therapy*
  • Age Factors
  • Aged
  • Cohort Studies
  • Diabetes Complications / complications
  • Diabetes Complications / epidemiology
  • Female
  • Humans
  • Intensive Care Units / standards
  • Intensive Care Units / statistics & numerical data
  • Male
  • Middle Aged
  • Multivariate Analysis
  • Oliguria / epidemiology
  • Oliguria / mortality
  • Patient Outcome Assessment*
  • Prevalence
  • Proportional Hazards Models
  • Prospective Studies
  • Renal Insufficiency, Chronic / complications
  • Renal Insufficiency, Chronic / mortality
  • Renal Replacement Therapy / adverse effects*
  • Renal Replacement Therapy / statistics & numerical data
  • Statistics, Nonparametric
  • Survivors / statistics & numerical data