Fluid Balance in Children Receiving Non-invasive Respiratory Support for Lower Respiratory Tract Illness in a Pediatric Intensive Care Unit

BACKGROUND Fluid management and the impact of fluid overload in children with lower respiratory illnesses (LRI) receiving non-invasive respiratory support (NIRS) are not well defined. We aim to evaluate fluid balance in children receiving NIRS and its association with clinical outcomes. METHODS A Prospective cohort study included children between 1 month and < 18 years admitted with LRI who received NIRS and were enrolled at admission from July 2023 to January 2025 in the Pediatric Intensive Care Unit of a private tertiary care hospital in Pakistan. Daily fluid balance was recorded, cumulative fluid balance, which is the sum of fluid balance over the entire PICU length of stay, indexed as the percentage of admission body weight, and peak fluid overload is the percentage of maximum positive fluid balance, were calculated. >10% fluid overload (FO) was considered a critical point. Association of Median daily fluid, cumulative fluid balance, and peak fluid overload with the duration of NIRS and PICU length of stay (LOS) was assessed. Multivariate analysis was performed using stepwise backward elimination, with p < 0.05 considered statistically significant. RESULTS Two hundred and sixty patients were enrolled in the study, median age was 12 months, and admitting diagnoses included pneumonia 41% (n = 102), bronchiolitis 26% (n = 67), and asthma 15% (n = 39). Positive cumulative fluid balance was observed in 191 (73%) children. Peak FO was stratified into four groups: <5% (n = 137), 5–10% (n = 63), 10–20% (n = 47), and > 20% (n = 12). In multivariable analysis, fluid overload was not significantly associated with the duration of NIRS (p = 0.622, 95% CI) or longer stay in PICU. (p = 0.652, at 95% CI). Subgroup analysis of children with bronchiolitis versus pneumonia and high-flow nasal cannula versus non-invasive mechanical ventilation also did not show a significant association. CONCLUSIONS In children with LRI receiving NIRS, fluid overload was frequently observed; however, it was not independently associated with the duration of NIRS or PICU LOS.