ELECTROLYTE DISTURBANCES ((SERIES)) 
HYPERNATRAEMIA
Na more than 145 mmol/l.
Severe symptoms mainly develop when Na > 160mmol/l.
more severe with acute hypernatraemia.
Chronic (> 5 days) well tolerated due to brain compensation.
Hypernatremia may lead to underestimation of degree of
dehydration:point_right:
Weight loss is more reliable.
The child may appear sicker than expected for the clinical
signs of dehydration that are present.
Shock occurs late because I.V volume is relatively preserved.
Look for signs of intracellular dehydration and neurological dysfunction:
Lethargy or Irritability.
Skin feels “doughy”.
Ataxia, tremor, Hyperreflexia.
Seizures, reduced GCS.
HYPONATRAEMIA
Hyponatraemia is defined as serum sodium < 135mmol/L.
Most children with Na > 125mmol/L are asymptomatic.
Hyponatraemia and rapid fluid shifts lead to cerebral oedema.
If Na < 125mmol/L or if serum sodium has fallen rapidly vague
symptoms such as nausea and malaise are more likely and
may progress.
If Na < 120mmol/L: headache, lethargy, obtundation & seizures
may occur.
Chronic hyponatraemia (developing > 24 hours)
Ch hyponatraemia:point_right: more subtle features( restlessness,
weakness, fatigue or irritability)
Rapid correction of hyponatraemia can result in osmotic
demyelination syndrome which manifests as😨((irreversible))
neurologic features (dysarthria, confusion, obtundation and
coma) which often present days after sodium correction.
Hyponatraemic seizures may be refractory to anticonvulsants and sodium correction should not be delayed.
((RCH GUIDELINES))