aetiology
Last reviewed 08/2022
Water overload:
- secondary to ADH secretion commonly occuring in hyaline membrane disease, ventilation pneumothorax or intraventricular haemorrhage
- in the first 24 hours due to excess fluid administration to the mother or child
- in acute renal failure before fluid restriction
Increased sodium losses:
- excess renal loss in the preterm baby is exacerbated by diuretic or aminophylline therapy
- inherited tubular disorders
- adrenal insufficiency - with dehydration and hyperkalaemia
- excess gastrointestinal losses in gastroenteritis
Inadequate sodium intake:
- late hyponatremia may be caused by inadequate sodium content during intravenous nutrition
- in the preterm after 2 weeks of low solute breast milk or formula. Preterm milk has a higher sodium concentration and should not be used after 4 to 6 weeks unless high sodium losses continue
intraventricular haemorrhage in neonates