Skip to main content

Fluid balance and renal outcomes in patients requiring renal replacement therapy in the ICU

Introduction

Fluid overload is associated with mortality in critically ill patients with acute kidney injury (AKI) [13]. We explored this relationship in patients with AKI who received renal replacement therapy (RRT) in the ICU to investigate the relationship between fluid balance and intradialytic hypotension with mortality and recovery of renal function.

Methods

We conducted a retrospective cohort study among patients aged ≥16 years who had RRT initiated and continued for ≥2 days in a level 2 or 3 ICU at two academic centres, and had fluid balance data available. Patients with end-stage kidney disease, within 1 year of a renal transplant or who had RRT initiated to treat a toxic ingestion were excluded. We used multivariable logistic regression to determine the relationship between mean daily fluid balance over the first 7 days following RRT initiation and the outcomes of mortality and RRT dependence in survivors.

Results

A total of 522 patients were included (319 male, mean age 64 years); 264 (50.6%) died in hospital. Survivors and those who died were similar with respect to age, weight and incidence of heart failure, liver cirrhosis and primary renal diagnoses. Independent risk factors for hospital mortality were higher Sequential Organ Failure Assessment score at RRT initiation (odds ratio (OR) = 1.18, 95% confidence interval = 1.11 to 1.25), higher Charlson comorbidity index (OR = 1.22, 1.09 to 1.37), lower baseline creatinine (OR = 0.984 per 10 μmol/l, 0.970 to 0.998), lower minimum mean arterial pressure (MAP) on day 1 (OR = 0.81 per 10 mmHg, 0.66 to 0.95) and more positive fluid balance for the first 7 days (OR 1.03 per 100 ml, 1.02 to 1.05). Of 172 hospital survivors, 57 (33.1%) were RRT dependent at discharge. Although univariable analysis suggested lower SOFA scores and higher baseline serum creatinine levels in those who remained RRT dependent, no factor was independently associated with RRT dependence at discharge in a multivariate model.

Conclusion

In this cohort of patients with AKI requiring RRT, a more positive fluid balance over 1 week and lower initial minimum MAP were associated with mortality. Among survivors, a less positive fluid balance was not associated with increased risk of RRT dependence at discharge, suggesting that conservative fluid management does not significantly attenuate renal recovery.

References

  1. 1.

    Bouchard J, et al.: Kidney Int. 2009, 76: 422-427. 10.1038/ki.2009.159

    Article  PubMed  Google Scholar 

  2. 2.

    Grams ME, et al.: Clin J Am Soc Nephrol. 2011, 6: 966-973. 10.2215/CJN.08781010

    PubMed Central  Article  PubMed  Google Scholar 

  3. 3.

    Payen D, et al.: Crit Care. 2008, 12: R74. 10.1186/cc6916

    PubMed Central  Article  PubMed  Google Scholar 

Download references

Author information

Affiliations

Authors

Corresponding author

Correspondence to JA Silversides.

Rights and permissions

This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated in a credit line to the data.

Reprints and Permissions

About this article

Cite this article

Silversides, J., Kuint, R., Pinto, R. et al. Fluid balance and renal outcomes in patients requiring renal replacement therapy in the ICU. Crit Care 17, P434 (2013). https://doi.org/10.1186/cc12372

Download citation

Keywords

  • Mean Arterial Pressure
  • Renal Replacement Therapy
  • Acute Kidney Injury
  • Sequential Organ Failure Assessment
  • Sequential Organ Failure Assessment Score