Background: Lower respiratory infection (LRTI) is one of
the serious illnesses, especially in less than 5 years of age
group requiring hospitalization and contributes to 30% of
deaths yearly worldwide mainly due to pneumonia as the
leading cause. Aim This study aimed to find the association
of hyponatremia (serum sodium less than 135 mEq/L) with
severe LRTI. Methods: This cross-sectional study was
conducted on 100 children admitted to PICU with severe
LRTI including bronchopneumonia (BPN), lobar
pneumonia, bronchiolitis, and empyema, all children were
subjected to full history taking, complete clinical
examination and investigations as complete blood count,
arterial blood gases, C-reactive protein, potassium and
sodium levels and radiological investigations as chest X-ray
and chest CT . The conditions were assessed by PRESS
score. Results: Most cases had normal sodium (63%), 3%
had severe hyponatremia, 10% had moderate hyponatremia,
19% had mild hyponatremia, and 5% had hypernatremia.
Children with hyponatremia had statistically higher
frequencies of MV, mortality and statistically longer
duration of oxygen support and hospital stay. At sodium
level