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Anterior shoulder instability — MRCEM SBA MCQ

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HardShoulder InjuriesAnterior shoulder instabilityMRCEM SBA

A patient with sodium 111 mmol/L has a generalised seizure and reduced consciousness. The duration of hyponatraemia is unknown. Which immediate sodium strategy is appropriate?

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Correct answer: B — Give monitored bolus 3% hypertonic saline for controlled early correction

The best answer is “Give monitored bolus 3% hypertonic saline for controlled early correction”. Seizure and depressed consciousness make this severe symptomatic hyponatraemia. Hypertonic 3% saline is given in monitored boluses to obtain a small prompt rise, commonly around 4–6 mmol/L, sufficient to reduce cerebral oedema and stop life-threatening symptoms. The goal is not immediate normalisation. Sodium is checked frequently and further therapy is controlled to avoid osmotic demyelination, particularly when chronicity is uncertain. Fluid restriction is too slow, isotonic saline may be ineffective or harmful in SIADH, and desmopressin is used selectively to control overcorrection.

Reference: Society for Endocrinology emergency guidance: severe symptomatic hyponatraemia: https://pmc.ncbi.nlm.nih.gov/articles/PMC5314809/