Five-year outcomes of severe acute kidney injury requiring renal replacement therapy

Nephrol Dial Transplant. 2008 Jul;23(7):2235-41. doi: 10.1093/ndt/gfn182. Epub 2008 Apr 11.


Background: Current research priorities in critical care medicine are focusing on long-term outcomes of survivors of critical illness. Severe acute kidney injury (AKI) is a common occurrence in intensive care. However, few studies have followed up these patients beyond 12 months after hospital discharge.

Methods: Of a cohort of 425 patients, 226 survivors with severe AKI necessitating renal replacement therapy (RRT) were followed up for 60 months after hospital discharge. None of these patients had pre-existing kidney disease. Vital status and renal function were documented annually for 5 years.

Results: None of the discharged or transferred patients was dependent on RRT; 57% had complete recovery and 43% had partial recovery of renal function. During the first year after hospital discharge, 18% of survivors died, during the second year 4% and during the third to fifth year 2% per year. At 5 years, 25% of the cohort were still alive. Further improvement in renal function (eGFR) was noted in 26 patients within the first year only. Deterioration of renal function occurred in eight patients. At 5 years, renal function was normal in 86% of the remaining survivors, it was impaired in 9% and 5% of the patients alive needed dialysis again. The proportional Cox regression analysis model showed that pre-existing extrarenal comorbidity, surgery and partial recovery of renal function were independent determinants of long-term survival.

Conclusions: This prospective observational study indicates that severe AKI is not only a determinant of excess in-hospital case fatalities of critically ill patients, but it also carries significant implications for long-term mortality.

MeSH terms

  • Acute Disease
  • Acute Kidney Injury / mortality
  • Acute Kidney Injury / physiopathology
  • Acute Kidney Injury / therapy*
  • Aged
  • Female
  • Follow-Up Studies
  • Glomerular Filtration Rate / physiology
  • Humans
  • Kaplan-Meier Estimate
  • Kidney Diseases / mortality
  • Kidney Diseases / physiopathology
  • Kidney Diseases / therapy*
  • Longitudinal Studies
  • Male
  • Middle Aged
  • Prognosis
  • Proportional Hazards Models
  • Prospective Studies
  • Renal Replacement Therapy*
  • Severity of Illness Index
  • Treatment Outcome