Hyponatremia as a Prognostic Marker in Children with Severe Lower Respiratory Tract Infections

Abstract

Introduction: Lower Respiratory Tract Infection is inflammation of airways below the level of larynx. It requires hospitalization in children below 5 years and accounts for 30% of global deaths annually. Various complications including electrolyte imbalances can be seen in such children. Hyponatremia is the most common electrolyte abnormality. Hyponatremia in pediatric pneumonia is mainly due to syndrome of inappropriate antidiuretic hormone secretion, whereas in bronchiolitis, is due to hyperinflation of lungs which reduces right atrial blood flow and stimulates vasopressin release leading to dilutional hyponatremia.

Aims: To find the association of hyponatremia with severe lower respiratory tract infection.

Methods: This cross-sectional study was conducted in 110 children, aged 2 months-14 years, with cough for less than 3 weeks, fast breathing, chest indrawing and Pediatric Respiratory Severity Score of 4-5. Serum sodium level was sent during admission. Monitoring was done for, need of oxygen support, any complications, duration of oxygen supplementation, total duration of hospital stay and final outcome of patient. Data were analyze during SPSS version 25.Chi-square test and Fisher exact test were used.

Results: Hyponatremia was detected in 38.18% children, of which 61.90% had mild hyponatremia, 33.33% had moderate and 4.76% had severe hyponatremia. Association of severity of hyponatremia with need of non-rebreathing face mask, mechanical ventilator, duration of hospital stay and final outcome was statistically significant (p-value<0.05). Mean duration of oxygen requirement was longer in hyponatremic children (5.8±1.2 days) than with normal sodium (2.7±0.8 days).

Conclusion: Hyponatremia was commonly seen in children with severe lower respiratory tract infections. It could adversely affect the morbidity in terms of need of oxygen supplement, duration of hospitalization, duration of oxygen requirement and mortality. Thus, monitoring of serum sodium and timely correction, if abnormal, is warranted to prevent complications, and improve outcomes in such children.