Hypernatraemia

Causes:

·      Major burns

·      Polyuric phase of ARF

·      Carbenoxalone

o   Causes pseudo hyperaldosteronism: Hypertension, hypokalaemia, hypernatraemia

Serum Na >145 mmol/L

Occurs when water intake is reduced or where water loss is increased (eg. Watery diarrhoea)

Usually picked up incidentally.

Check hyperglycaemia and hypercalcaemia

Check urine and plasma osmolality

–       Urine osm < plasma osm = consider diabetes insipidus

–       Urine osm > plasma osm = consider osmotic diuresis/ heatstroke

If patient is also hypovolaemic, then monitor UO and renal function

Treatment:

Treat underlying cause

IN mild cases, replace missing body water with water or glucose 5% iv

IN severe cases, (eg >170) – give iv 5% glucose if normovolameic or 5% saline if hypovolaemic