Relationship of hyponatremia in bronchiolitis to clinical outcomes

Abstract

For many years, hyponatremia has been recognized in adult critical care as a predictor of worse outcomes. The reasons for the phenomenon are not clear but may be due to the direct effects of reduced sodium concentrations leading to abnormal fluid shifts. Some of these patients have syndrome of inappropriate anti-diuretic hormone, and others have iatrogenic fluid overload. There have been few studies in the pediatric population. In this issue of The Journal, Luu et al from the University of Colorado report a retrospective cohort study of children admitted to the pediatric intensive care unit (PICU) with bronchiolitis. Serum sodium concentrations were obtained within the first two hours of admission and correlated with clinical outcomes. Results showed that 22% of 102 children had hyponatremia within two hours of admission. These children had increased mortality, increased days on the mechanical ventilator, increased PICU length of stay, and increased need for noninvasive ventilatory support. The authors conclude that children with bronchiolitis who have a serum sodium of less than 135 mEq/L within two hours of admission to the PICU fare worse than their cohorts with normal sodium values. This conclusion begs the question: What is the mechanism, and should this be the focus of future investigations? The type and composition of fluid administered during the first 24 hours will be an important variable to study. Hyponatremia in Children with Bronchiolitis Admitted to the Pediatric Intensive Care Unit Is Associated with Worse OutcomesThe Journal of PediatricsVol. 163Issue 6PreviewTo characterize the relationship between hyponatremia (serum sodium <135 mEq/L) and clinical outcomes in children ages 1 month to 2 years admitted to the pediatric intensive care unit (PICU) with bronchiolitis. Full-Text PDF