INTRODUCTION: Lower respiratory tract infection (LRTI) is a serious illness especially in under 5 years of age. Hyponatremia is the most common electrolyte abnormality seen in hospitalized children. This study aimed at evaluating the correlation between hyponatremia in children admitted to the pediatric ward, in the setting of acute LRTI in different age groups and to determine the association of hyponatremia with different types of acute LRTI in children.

METHODS: This study included 231 clinically diagnosed children (1 month to 12 years) of acute LRTI. General examination and systemic examination was done. Laboratory investigations included serum electrolyte level (Na+) and radiological investigation included chest X-ray. There were Bronchopneumonia (BPN), lobar pneumonia, wheeze-associated lower respiratory tract infection (WALRI), bronchiolitis, and empyema were characterized in children. Statistical analysis was done using SPSS 16.0 version. P-value <0.05 was considered statistically significant.

RESULTS: Out of 231 cases, hyponatremia was present in 136 cases (58.9%). Mild, moderate, and severe hyponatremia were present in 83.8%, 13.2%, and 2.9% patients, respectively. Most of the patients with BPN had mild hyponatremia (89%). The prevalence of hyponatremia was significantly higher in age 6-10 years (OR=4.29, 95%CI=0.90-20.45, p<0.05), females (OR=0.56, 95%CI=0.32-0.96, p=0.03) and cases of empyema (OR=4.49, 95%CI=1.48-13.60, p=0.008).

DISCUSSION AND CONCLUSION: In conclusion, among children hospitalized with LRTI, an older age (6-10 years), being female, and the presence of empyema are significant risk factors for the development of hyponatremia. In such children, serum electrolytes should be regularly measured to prevent adverse clinical outcomes.