Long-term survival and dialysis dependency following acute kidney injury in intensive care: extended follow-up of a randomized controlled trial

PLoS Med. 2014 Feb 11;11(2):e1001601. doi: 10.1371/journal.pmed.1001601. eCollection 2014 Feb.

Abstract

Background: The incidence of acute kidney injury (AKI) is increasing globally and it is much more common than end-stage kidney disease. AKI is associated with high mortality and cost of hospitalisation. Studies of treatments to reduce this high mortality have used differing renal replacement therapy (RRT) modalities and have not shown improvement in the short term. The reported long-term outcomes of AKI are variable and the effect of differing RRT modalities upon them is not clear. We used the prolonged follow-up of a large clinical trial to prospectively examine the long-term outcomes and effect of RRT dosing in patients with AKI.

Methods and findings: We extended the follow-up of participants in the Randomised Evaluation of Normal vs. Augmented Levels of RRT (RENAL) study from 90 days to 4 years after randomization. Primary and secondary outcomes were mortality and requirement for maintenance dialysis, respectively, assessed in 1,464 (97%) patients at a median of 43.9 months (interquartile range [IQR] 30.0-48.6 months) post randomization. A total of 468/743 (63%) and 444/721 (62%) patients died in the lower and higher intensity groups, respectively (risk ratio [RR] 1.04, 95% CI 0.96-1.12, p = 0.49). Amongst survivors to day 90, 21 of 411 (5.1%) and 23 of 399 (5.8%) in the respective groups were treated with maintenance dialysis (RR 1.12, 95% CI 0.63-2.00, p = 0.69). The prevalence of albuminuria among survivors was 40% and 44%, respectively (p = 0.48). Quality of life was not different between the two treatment groups. The generalizability of these findings to other populations with AKI requires further exploration.

Conclusions: Patients with AKI requiring RRT in intensive care have high long-term mortality but few require maintenance dialysis. Long-term survivors have a heavy burden of proteinuria. Increased intensity of RRT does not reduce mortality or subsequent treatment with dialysis.

Trial registration: www.ClinicalTrials.govNCT00221013.

Publication types

  • Multicenter Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acute Kidney Injury / diagnosis
  • Acute Kidney Injury / mortality
  • Acute Kidney Injury / therapy*
  • Aged
  • Albuminuria / mortality
  • Albuminuria / therapy
  • Australia
  • Chi-Square Distribution
  • Female
  • Humans
  • Intensive Care Units*
  • Kaplan-Meier Estimate
  • Male
  • Middle Aged
  • Multivariate Analysis
  • New Zealand
  • Odds Ratio
  • Prevalence
  • Proportional Hazards Models
  • Prospective Studies
  • Renal Dialysis* / adverse effects
  • Renal Dialysis* / mortality
  • Risk Factors
  • Survivors*
  • Time Factors
  • Treatment Outcome

Associated data

  • ClinicalTrials.gov/NCT00221013

Grant support

This study was supported by an Australian Government NHMRC Project Grant (#632811). MG's work on this study was supported by a Jacquot Fellowship from the Royal Australasian College of Physicians. AC was supported by a NHMRC Senior Research Fellowship. JM is supported by a Practitioner Fellowship from the National Health and Medical Research Council. No funding bodies had any role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.