Fluid Overload and Mortality in Children Receiving Continuous Renal Replacement Therapy: The Prospective Pediatric Continuous Renal Replacement Therapy Registry

Sutherland, Scott M.; Zappitelli, Michael; Alexander, Steven R.; Chua, Annabelle N.; Brophy, Patrick D.; Bunchman, Timothy E.; Hackbarth, Richard; Somers, Michael J.G.; Baum, Michelle; Symons, Jordan M.; Flores, Francisco X.; Benfield, Mark; Askenazi, David; Chand, Deepa; Fortenberry, James D.; Mahan, John D.; McBryde, Kevin; Blowey, Douglas; Goldstein, Stuart L.

doi:10.1053/j.ajkd.2009.10.048

« Previous Next »American Journal of Kidney Diseases
Volume 55, Issue 2 , Pages 316-325, February 2010

Fluid Overload and Mortality in Children Receiving Continuous Renal Replacement Therapy: The Prospective Pediatric Continuous Renal Replacement Therapy Registry

Scott M. Sutherland, MD
- Department of Pediatrics, Stanford University School of Medicine and Lucile Packard Children's Hospital, Palo Alto, CA
- Address correspondence to Scott M. Sutherland, MD, Stanford University Medical Center, 300 Pasteur Dr, Rm G-306, Stanford, CA 94305
Michael Zappitelli, MD, MSc
- Department of Pediatrics, Division of Nephrology, Montreal Children's Hospital, McGill University Health Centre, Montreal, Canada
Steven R. Alexander, MD
- Department of Pediatrics, Stanford University School of Medicine and Lucile Packard Children's Hospital, Palo Alto, CA
Annabelle N. Chua, MD
- Department of Pediatrics, Renal Section, Baylor College of Medicine and Texas Children's Hospital, Houston, TX
Patrick D. Brophy, MD
- Department of Pediatrics, Division of Nephrology, University of Iowa Children's Hospital, Iowa City, IA
Timothy E. Bunchman, MD
- Department of Pediatrics and Human Development, Michigan State University and Helen DeVos Children's Hospital, Grand Rapids, MI
Richard Hackbarth, MD
- Department of Pediatrics and Human Development, Michigan State University and Helen DeVos Children's Hospital, Grand Rapids, MI
Michael J.G. Somers, MD
- Department of Pediatrics, Division of Nephrology, Harvard Medical School and Children's Hospital, Boston, MA
Michelle Baum, MD
- Department of Pediatrics, Division of Nephrology, Harvard Medical School and Children's Hospital, Boston, MA
Jordan M. Symons, MD
- Department of Pediatrics, University of Washington School of Medicine and Children's Hospital and Regional Medical Center, Seattle, WA
Francisco X. Flores, MD
- Department of Pediatrics, Division of Nephrology, University of South Florida College of Medicine, All Children's Hospital, St. Petersburg, FL
Mark Benfield, MD
- Division of Pediatric Nephrology, Children's Hospital of Alabama, University of Alabama at Birmingham, Birmingham, AL
David Askenazi, MD
- Division of Pediatric Nephrology, Children's Hospital of Alabama, University of Alabama at Birmingham, Birmingham, AL
Deepa Chand, MD
- Department of Pediatric Nephrology, Akron Children's Hospital, Akron, OH
James D. Fortenberry, MD
- Department of Pediatrics, Emory University School of Medicine and Children's Healthcare of Atlanta at Egleston, Atlanta, GA
John D. Mahan, MD
- Department of Pediatrics, Ohio State University College of Medicine and Public Health and Columbus Children's Hospital, Columbus, OH
Kevin McBryde, MD
- Department of Nephrology, Children's National Medical Center, Washington DC
Douglas Blowey, MD
- Department of Pediatric Nephrology, Children's Mercy Hospital and Clinics, Kansas City, MO
Stuart L. Goldstein, MD
- Department of Pediatrics, Renal Section, Baylor College of Medicine and Texas Children's Hospital, Houston, TX

Received 26 February 2009; accepted 30 October 2009. published online 31 December 2009.

Background

Critically ill children with hemodynamic instability and acute kidney injury often develop fluid overload. Continuous renal replacement therapy (CRRT) has emerged as a favored modality in the management of such children. This study investigated the association between fluid overload and mortality in children receiving CRRT.

Study Design

Prospective observational study.

Setting & Participants

297 children from 13 centers across the United States participating in the Prospective Pediatric CRRT Registry.

Predictor

Fluid overload from intensive care unit (ICU) admission to CRRT initiation, defined as a percentage equal to (fluid in [L] − fluid out [L])/(ICU admit weight [kg]) × 100%.

Outcome & Measurements

The primary outcome was survival to pediatric ICU discharge. Data were collected regarding demographics, CRRT parameters, underlying disease process, and severity of illness.

Results

153 patients (51.5%) developed < 10% fluid overload, 51 patients (17.2%) developed 10%-20% fluid overload, and 93 patients (31.3%) developed ≥ 20% fluid overload. Patients who developed ≥ 20% fluid overload at CRRT initiation had significantly higher mortality (61/93; 65.6%) than those who had 10%-20% fluid overload (22/51; 43.1%) and those with < 10% fluid overload (45/153; 29.4%). The association between degree of fluid overload and mortality remained after adjusting for intergroup differences and severity of illness. The adjusted mortality OR was 1.03 (95% CI, 1.01-1.05), suggesting a 3% increase in mortality for each 1% increase in severity of fluid overload. When fluid overload was dichotomized to ≥ 20% and < 20%, patients with ≥ 20% fluid overload had an adjusted mortality OR of 8.5 (95% CI, 2.8-25.7).

Limitations

This was an observational study; interventions were not standardized. The relationship between fluid overload and mortality remains an association without definitive evidence of causality.

Conclusions

Critically ill children who develop greater fluid overload before initiation of CRRT experience higher mortality than those with less fluid overload. Further goal-directed research is required to accurately define optimal fluid overload thresholds for initiation of CRRT.

Index Words: Continuous renal replacement therapy (CRRT), acute kidney injury, fluid overhead, pediatric