Significance of Serum Sodium Level as Potential Severity Biomarker in Pediatric Acute Bronchiolitis

Abstract

Introduction: Due to viral infection, specifically RSV, acute bronchiolitis, which is common in infants under two years old, increases in the winter. Most of the time, supportive treatment can alleviate moderate symptoms. Hospitalization is required in severe cases, particularly in high-risk newborns. Because of fluid therapy and high levels of antidiuretic hormone, hyponatremia—which is frequently observed in cases of severe bronchiolitis—may be a sign of a more serious illness. Preventing mortality in at-risk newborns requires early detection of extrapulmonary symptoms.

Aim: The purpose of this study is to determine whether there is any correlation, if any, between the severity of the illness and its prognosis in hospitalized children with acute bronchiolitis.

Material and Methods: This prospective observational study was carried out on children aged one month to two years who were admitted with acute bronchiolitis at a tertiary care hospital in eastern India.

Results: The study found that 19.2% of children with acute bronchiolitis developed hyponatremia, with most having mild (78.3%) or moderate (21.7%) cases. Initial severity on admission varied, with moderate bronchiolitis most common (71.7%). Significant differences in serum sodium levels were observed among severity groups, being higher in mild cases (141.60±4.48) compared to severe (135.11±6.52). Hyponatremic children had longer hospital stays (7.57±2.51 days) than normonatremic ones (6.00±2.2), correlating negatively with serum sodium levels (r= -0.57, p=0.003).

Conclusion: According to the study's findings, children with acute bronchiolitis—mostly mild to moderate in severity—have a significant prevalence of hyponatremia. Milder cases of bronchiolitis are correlated with higher initial serum sodium levels. Significantly, hyponatremia is linked to longer hospital stays, suggesting that it may serve as a marker for the severity of the illness and the length of hospital stay in these patients.