Related Experiment Video
Updated: Jun 2, 2026
Evaluation of Fluid Overload by Bioelectrical Impedance Vectorial Analysis
Published on: August 17, 2022
Weight-based determination of fluid overload status and mortality in pediatric intensive care unit patients requiring
David T Selewski1, Timothy T Cornell, Rebecca M Lombel
1Division of Nephrology, Department of Pediatrics and Communicable Diseases, C.S. Mott Children's Hospital, University of Michigan, Ann Arbor, MI, USA. dselewsk@med.umich.edu
Insights
Fluid overload (FO) in pediatric intensive care unit (PICU) patients receiving continuous renal replacement therapy (CRRT) is linked to mortality. A new weight-based FO method is practical and predicts outcomes, offering a bedside tool for clinicians.
Area of Science:
- Pediatric Critical Care Medicine
- Nephrology
- Clinical Outcomes Research
Background:
- Fluid overload (FO) at continuous renal replacement therapy (CRRT) initiation is a known mortality risk in pediatric intensive care unit (PICU) patients.
- Traditional FO assessment using daily fluid balance is labor-intensive and prone to errors.
- A more practical and accurate method for assessing FO is needed.
Purpose of the Study:
- To evaluate a weight-based definition of FO at CRRT initiation in PICU patients.
- To compare the accuracy and practicality of weight-based FO assessment with the standard fluid balance method.
- To determine if weight-based FO assessment predicts mortality in PICU patients.
Main Methods:
- Retrospective single-center review of 113 PICU patients requiring CRRT.
- Comparison of FO degree using standard fluid balance versus weight-based methods (PICU admission weight and hospital admission weight).
- Univariate and multivariate analyses to assess FO prediction of mortality.
Main Results:
- Greater FO degrees were observed in nonsurvivors, regardless of the assessment method.
- Univariate analysis showed similar odds ratios for mortality per 1% FO increase across all three methods.
- Multivariate analyses indicated all methods approached significance in predicting PICU survival.
Conclusions:
- Weight-based definitions of FO are effective for assessing FO at CRRT initiation in PICU patients.
- Weight-based FO assessment is associated with increased mortality in a broad PICU population.
- This study supports a practical, weight-based FO definition for bedside use in PICU settings.
Purpose:
In pediatric intensive care unit (PICU) patients, fluid overload (FO) at initiation of continuous renal replacement therapy (CRRT) has been reported to be an independent risk factor for mortality. Previous studies have calculated FO based on daily fluid balance during ICU admission, which is labor intensive and error prone. We hypothesized that a weight-based definition of FO at CRRT initiation would correlate with the fluid balance method and prove predictive of outcome.
Methods:
This is a retrospective single-center review of PICU patients requiring CRRT from July 2006 through February 2010 (n = 113). We compared the degree of FO at CRRT initiation using the standard fluid balance method versus methods based on patient weight changes assessed by both univariate and multivariate analyses.
Results:
The degree of fluid overload at CRRT initiation was significantly greater in nonsurvivors, irrespective of which method was used. The univariate odds ratio for PICU mortality per 1% increase in FO was 1.056 [95% confidence interval (CI) 1.025, 1.087] by the fluid balance method, 1.044 (95% CI 1.019, 1.069) by the weight-based method using PICU admission weight, and 1.045 (95% CI 1.022, 1.07) by the weight-based method using hospital admission weight. On multivariate analyses, all three methods approached significance in predicting PICU survival.
Conclusions:
Our findings suggest that weight-based definitions of FO are useful in defining FO at CRRT initiation and are associated with increased mortality in a broad PICU patient population. This study provides evidence for a more practical weight-based definition of FO that can be used at the bedside.
Related Concept Videos
01:30Continuous Renal Replacement Therapy
01:26Extracorporeal Removal of Drugs: Continuous Renal Replacement Therapy
01:20Acute Kidney Injury V: Interprofessional Care
01:28Drug Dosing in Renal Diseases: Estimation of Glomerular Filtration Rate Based on Serum Creatinine Concentration
01:22Acute Kidney Injury VI: Nursing Management
01:25Drug Dosing in Renal Diseases: Dose Adjustments Based on Drug Clearance and Elimination Rate Constant