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Abstract: FR-PO275

Chloride Increase Following Continuous Renal Replacement Therapy (CRRT) Initiation Is Associated with Mortality

Session Information

Category: Fluid and Electrolytes

  • 902 Fluid and Electrolytes: Clinical


  • Griffin, Benjamin, University of Colorado, Aurora, Colorado, United States
  • Arruda, Nigel, University of Colorado, Aurora, Colorado, United States
  • Teitelbaum, Isaac, University of Colorado Health Science Center, 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
  • Barhight, Matthew, Childrens Hospital Colorado, Aurora, Colorado, United States
  • Gist, Katja M., University of Colorado, Children''s Hospital Colorado, Aurora, Colorado, United States
  • Faubel, Sarah, University of Colorado Denver, Denver, Colorado, United States

Hyperchloremia is common in critically ill patients, and recent studies are increasingly linking elevated serum chloride with mortality. CRRT can rapidly shift chloride levels, and it is unclear what impact these changes have on patient outcomes. In this study we examined the association between changes in chloride following CRRT initiation and mortality.


We conducted a retrospective analysis of adult patients initiated on CRRT at the University of Colorado Hospital between July 2015 and September 2016. The main exclusion criterion was death within 24 hours of CRRT initiation. Chloride levels were measured upon admission to the ICU, prior to CRRT initiation, and every 8 hours thereafter until CRRT was discontinued. Changes in chloride were calculated from admission value to CRRT initiation. Changes after CRRT initiation were calculated from the first value following CRRT initiation to the highest value while on treatment. The primary outcome was in-hospital mortality. Logistic regression was used to adjust for SOFA score, body mass index, and gender.


A total of 127 cases were included in the analysis. Average chloride on admission was 102 ± 6.7 mEq/L and 106 ± 8.3 mEq/L at CRRT initiation. After adjusting for all covariables, chloride on admission, though not at CRRT initiation, predicted mortality: for every 1 mEq/L increase in admission chloride there was an 8% increased risk of mortality. Mean changes in chloride from admission to CRRT initiation and from CRRT initiation to end of therapy were 3.6 ± 7.4 mEq/L and 2.8 ± 3.5 mEq/L respectively. Change in chloride from admission to CRRT initiation was not significantly associated with in-hospital mortality. Notably, change in chloride of 1 mEq/L following CRRT initiation was associated with a 15% increased risk of mortality.


Hyperchloremia upon ICU admission is associated with increased mortality. Increases in chloride levels following CRRT initiation are also associated with mortality, even after adjusting for illness severity. The role of chloride in critical illness, particularly in those requiring CRRT, warrants further investigation.


  • Other NIH Support