Fluid overload at initiation of renal replacement therapy is associated with lack of renal recovery in patients with acute kidney injury

Nephrol Dial Transplant. 2012 Mar;27(3):956-61. doi: 10.1093/ndt/gfr470. Epub 2011 Aug 19.


Background: Patients with acute kidney injury (AKI) requiring initiation of renal replacement therapy (RRT) have poor short- and long-term outcomes, including the development of dialysis dependence. Currently, little is known about what factors may predict renal recovery in this population.

Methods: We conducted a single-center, retrospective analysis of 170 hospitalized adult patients with AKI attributed to acute tubular necrosis who required inpatient initiation of RRT. Data collection included patient characteristics, laboratory data, details of hospital course and degree of fluid overload at RRT initiation. The primary outcome was recovery of renal function to dialysis independence.

Results: Within 1 year of RRT initiation, 35.9% (61/170) of patients reached the primary end point of renal recovery. The median (interquartile range) duration of RRT was 11 (3-33) days and 83.6% (51/61) recovered prior to hospital discharge. Recovering patients had significantly less fluid overload at the time of RRT initiation compared to non-recovering patients (3.5 versus 9.3%, P = 0.004). In multivariate Cox proportional hazard regression analysis, a rise in percent fluid overload at dialysis initiation remained a significant negative predictor of renal recovery (hazard ratio 0.97, 95% confidence interval 0.95-1.00, P = 0.024).

Conclusions: In patients with AKI, a higher degree of fluid overload at RRT initiation predicts worse renal recovery at 1 year. Clinical trials are needed to determine whether interventions targeting fluid overload may improve patient and renal outcomes.

MeSH terms

  • Acute Kidney Injury / complications
  • Acute Kidney Injury / mortality*
  • Acute Kidney Injury / therapy*
  • Adult
  • Aged
  • Body Fluids*
  • Female
  • Fluid Therapy / adverse effects*
  • Humans
  • Male
  • Middle Aged
  • Renal Replacement Therapy*
  • Retrospective Studies
  • Survival Rate
  • Time Factors
  • Water Intoxication / etiology*