Outcome of Bronchiolitis with Hyponatremia

Abstract Introduction: Bronchiolitis is one of the most prevalent lower respiratory tract infections in infants in Bangladesh. Hyponatremia may develop in bronchiolitis patients, which may be associated with worse outcomes. Objective: To see the association between hyponatremia and in-hospital outcomes of children with bronchiolitis. Materials and Methods: This prospective cohort study was conducted in the department of pediatrics of a tertiary care hospital on 160 bronchiolitis patients from 1 month to 2 years of age. Serum sodium concentration was measured. Patients were grouped into hyponatremic and normonatremic. Hyponatremic patients were further classified into mild, moderate, and severe. Observable outcome variables were the length of hospital stay, need for noninvasive ventilation (NIV), mechanical ventilation, frequency of heart failure (HF), seizure, and mortality. Results: Among 160 patients, 40 (25%) had hyponatremia and 120 (75%) had normonatremia. Among the hyponatremic patients, 80% had mild, 15% had moderate, and 5% had severe hyponatremia. Hyponatremic bronchiolitis patients had longer median length of hospital stay in comparison with normonatremic patients (7 days vs. 4 days; P < 0.001), higher need for NIV (60% vs. 18.2%; P < 0.001) and higher frequency of HF (20% vs. 2.5%; P < 0.001). Conclusion: Hyponatremia was frequently observed in bronchiolitis, which seems to be associated with higher morbidity.