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Severe symptomatic hyponatraemia — SCE Acute Medicine MCQ

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HardAcute Renal and Metabolic EmergenciesSevere symptomatic hyponatraemiaSCE Acute Medicine

A 62-year-old woman with small-cell lung cancer has a generalised seizure on the AMU. Sodium is 110 mmol/L, serum osmolality is low and she is euvolaemic. CT head shows no acute bleed. What is the most important immediate action?

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Correct answer: A — Give hypertonic saline bolus with close sodium monitoring

Seizure with severe hyponatraemia requires immediate hypertonic saline to raise sodium enough to reduce cerebral oedema, with careful monitoring to avoid overcorrection. Oral measures are too slow for severe symptoms. Desmopressin may be used to control overcorrection in selected cases, not as the first therapy for a seizure. The pearl is that the initial target is symptom improvement, not normal sodium.

Reference: Society for Endocrinology hyponatraemia emergency guidance