Weight variability at pediatric intensive care unit admission and adverse outcomes in critically ill children

Abstract

Background: Body weight can fluctuate during critical illness due to factors such as fluid shifts, nutritional status, the type of acute illness, and underlying comorbidities. We investigated the association between acute body weight variability (WV) and clinical outcomes in critically ill pediatric patients. Methods: We retrospectively analyzed data from patients aged 1 month to 18 years who were admitted to the pediatric intensive care unit (PICU) of a university-affiliated tertiary hospital between August 2017 and July 2021. WV was defined as the percentage difference between the measured body weight at PICU admission and the usual body weight, obtained either from recent hospital records or caregiver reports. Associations between WV and clinical outcomes, including PICU mortality and ventilator-free days (VFDs), were assessed. Results: Of the 926 patients, 74 (8.0%) died. Median WV was significantly higher in non-survivors than in survivors (8.7% vs. 0.0%, P<0.001). Increased WV was independently associated with higher mortality (hazard ratio [HR], 1.102; 95% CI, 1.073-1.131) and fewer VFDs (odds ratio [OR], 0.599; 95% CI, 0.524-0.684). Combining WV with Pediatric Index of Mortality 3 score significantly improved mortality prediction over either parameter alone (area under the curve, 0.888; P=0.047). Conclusions: Higher WV at PICU admission is independently associated with adverse clinical outcomes, including increased mortality and fewer VFDs. WV could complement existing mortality prediction models in pediatric critical care.