Sat27November0556PM 26

A 26-year-old woman with a past history of schizophrenia is admitted via the Emergency Department with nausea and lethargy.

On clinical examination, she is clinically euvolaemic with Glasgow Coma Score (GCS) of 14. There are no focal neurological signs. The serum sodium concentration is 114 mmol/L. There is no history of seizure activity.

What is the most appropriate next step in correcting her abnormal biochemistry?

(Please select 1 option)

Demeclocycline PO

Fluid restriction This is the correct answer

Furosemide 50 mg IV

3% N. saline infusion

0.9% N. saline infusion Incorrect answer selected

Explanation

The most likely diagnosis is a syndrome of inappropriate antidiuretic hormone (SIADH) secretion. The most likely cause in this patient is her medication. Numerous psychiatric medications, particularly antipsychotics such as haloperidol, quetiapine, and clozapine can cause this condition.

Although her sodium is very low, she has not suffered any seizures and we must be wary of raising serum sodium by more than 10 mmol/24 hours due to the risk of central pontine myelinolysis. Fluid restriction is the first step with ADH antagonists such as tolvaptan and demeclocyline reserved for more refractory cases.

As the patient appears volume replete, administration of saline is not the correct initial move. The problem is due to an excess of free body water; therefore, restriction of this is the first step.

Reference:

Clinical review: Practical approach to hyponatraemia and hypernatraemia in critically ill patients

Answer Statistics

1

7%

2

34%

3

1%

4

45%

5

16%

Times answered: 280