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Guillain-Barré syndrome — SCE Acute Medicine MCQ

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ModerateAcute Neurological PresentationsGuillain-Barré syndromeSCE Acute Medicine

A 37-year-old man is assessed on the acute medical unit. He has ascending weakness 10 days after diarrhoeal illness. Reflexes are absent and he reports mild breathlessness when lying flat. Initial assessment includes relevant observations, bedside tests and urgent blood results. What is the most appropriate investigation?

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Correct answer: A — Measure forced vital capacity regularly

Measure forced vital capacity regularly is the best answer because GBS can cause respiratory muscle failure, so serial vital capacity guides urgent escalation. Plasma glucose and beta-hydroxybutyrate is plausible, but it is less appropriate for the physiology or timing described in this stem. The other distractors either fit a neighbouring presentation, delay definitive treatment, or miss the key immediate risk. Clinical pearl: Autonomic instability is another important cause of deterioration.

Reference: https://cks.nice.org.uk/#acute-medicine-order-50-1