Five-year outcomes of severe acute kidney injury requiring renal replacement therapy.
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.
Schiffl
Helmut
H
Department of Internal Medicine-Campus Innenstadt, University of Munich, Munich, Germany. helmut.schiffl@kfh-dialyse.de
Fischer
Rainald
R
D000208:Acute Disease; D058186:Acute Kidney Injury / Q000401:mortality / Q000503:physiopathology / Q000628:therapy*; D000368:Aged; D005260:Female; D005500:Follow-Up Studies; D005919:Glomerular Filtration Rate / Q000502:physiology; D006801:Humans; D053208:Kaplan-Meier Estimate; D007674:Kidney Diseases / Q000401:mortality / Q000503:physiopathology / Q000628:therapy*; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D016016:Proportional Hazards Models; D011446:Prospective Studies; D017582:Renal Replacement Therapy; D012720:Severity of Illness Index; D016896:Treatment Outcome