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Abstract: FR-PO279

Fluid Overload Predicts Mortality in Critically Ill Patients Undergoing Continuous Renal Replacement Therapy

Session Information

Category: Fluid and Electrolytes

  • 902 Fluid and Electrolytes: Clinical


  • Arruda, Nigel, University of Colorado, Aurora, Colorado, United States
  • Griffin, Benjamin, University of Colorado, Aurora, Colorado, United States
  • Barhight, Matthew, Childrens Hospital Colorado, Aurora, Colorado, United States
  • Gist, Katja M., University of Colorado, Children''s Hospital Colorado, Aurora, Colorado, United States
  • Jovanovich, Anna Jeanette, Denver VA / University of Colorado, Denver, Colorado, United States
  • Aftab, Muhammad, University of Colorado, Anschutz Medical Center, Aurora, Colorado, United States
  • Faubel, Sarah, University of Colorado Denver , Denver, Colorado, United States

Acute kidney injury (AKI) requiring renal replacement therapy (RRT) is common in the intensive care unit (ICU) and has a mortality rate of >50%. Fluid overload (FO) >10% of body weight has been shown to be deleterious in ICU patients, but studies specifically evaluating patients with severe AKI requiring continuous renal replacement therapy (CRRT) remain limited. Furthermore, the effects of volume removal following CRRT initiation are not well described. The purpose of this study was to examine the impact of (1) FO at CRRT initiation and (2) fluid removal on in-hospital mortality.


We conducted a retrospective analysis of adult ICU patients who underwent CRRT for a minimum of 24 hours at University of Colorado Hospital from September 2015 to July 2016. Patients were characterized by fluid balance at initiation of CRRT and total volume removed by CRRT during their hospitalization. The primary outcome was in-hospital mortality. Logistic regression was used to adjust for Sequential Organ Failure Assessment (SOFA) score, gender, and body mass index.


A total of 87 patients were included in the final analysis, of which 41 (47.1%) patients had FO >10% of body weight at the time of CRRT initiation. Negative fluid balance on CRRT was achieved in 64 (73.5%) patients. The adjusted odds ratio for mortality in those with >10% FO was 2.69 (Table 1). There was no association between mortality and negative fluid balance on CRRT.


Our study adds to prior studies showing that fluid overload is independently associated with increased mortality in ICU patients requiring CRRT. However, we found no significant association between fluid balance during CRRT and mortality. The effect of fluid balance on mortality in ICU patients requiring RRT, both before and after RRT initiation, merits further investigation.

Table 1. Final multivariate model for in-hospital mortality
VariableOR (95% CI)p-value
Fluid Overload > 10%*2.69 (1.02 – 7.14)0.046
Negative Fluid Balance on RRT^1.16 (0.39 - 3.02)0.9
SOFA Score1.14 (0.97 – 1.34)0.1
Female Gender0.79 (0.32 – 1.99)0.8
Body Mass Index1.02 (0.96 – 1.34)0.5

* Comparison group is Fluid Overload < 0% ^ Comparison group is Positive Fluid Balance on RRT


  • Other NIH Support