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

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 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.