Clinical approach to the patient with hyponatremia

Clinical approach to the patient with hyponatremia

1.         Confirm the patient truly has a hypo-osmolar state by checking serum osmolality

2.         Assess for serious signs or symptoms suggesting cerebral edema

3.         Determine the duration of development of hyponatremia (less or more than 48 hours)

4.         Assess the patient’s extracellular fluid volume status using clinical examination and laboratory testing (spot urine sodium, serum uric acid)

5.         Check the urine osmolality to see if the urine is appropriately dilute (< 100 mOsm/kg) or inappropriately concentrated (≥ 100 mOsm/kg)

6.         Assess for underlying causes of hyponatremia that may correct rapidly with treatment (eg, hyponatremia induced by thiazide diuretics)

7.         Assess the patient’s medications (intravenous antibiotics, infusions) and nutritional intake (total parenteral nutrition, tube-feeding) for sources of water

8.  Look for drugs the patient is taking that potentiate antidiuretic hormone action (ie, selective serotonin uptake inhibitors)