Severe hyponatremia can cause neurological symptoms, seizures, coma, and death.
Prompt recognition and correction of severe hyponatremia are crucial to prevent complications.
A thorough medication review is necessary. Medications like thiazide diuretics, SSRIs, and antiepileptic drugs can cause hyponatremia.
Urine sodium concentration can aid in determining the cause of hyponatremia, with levels below 20 mmol/L suggesting extrarenal salt losses and levels above 40 mmol/L indicating renal salt wasting.
Overly rapid correction of chronic hyponatremia (more than 48 hours) can lead to osmotic demyelination syndrome (formerly central pontine myelinolysis), which is rare in patients with plasma sodium above 120 mEq/L.
To avoid central pontine myelinolysis, sodium should not be corrected faster than 0.5 mmol/L/hr unless patient is seriously symptomatic. Some experts advocate for a more conservative approach, targeting 4-6 mmol/L/day with a maximum of 8 mmol/L/day.