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Thyrotoxicosis Pre-Operative Optimisation — FRCA Final MCQ

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ModeratePreoperative AssessmentThyrotoxicosis Pre-Operative OptimisationFRCA Final

A 55-year-old woman is scheduled for a total thyroidectomy for thyrotoxicosis. She is on carbimazole and propranolol. Pre-operatively her free T4 is 45 pmol/L (normal 12-22). What is the most appropriate pre-operative action?

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Correct answer: C — Start dexamethasone and proceed

Elective thyroidectomy for thyrotoxicosis should be deferred until the patient is rendered euthyroid (normal fT4 and fT3) to reduce the risk of thyroid storm (perioperative thyrotoxic crisis). Carbimazole should be continued and dose adjusted, with propranolol for rate control. Lugol's iodine (potassium iodide) may be given for 10-14 days pre-operatively to reduce thyroid vascularity and gland friability, making surgery safer – but only after achieving near-euthyroid state. Emergency surgery on an unprepared thyrotoxic patient carries significant mortality risk.

Reference: NICE – 2019 – NG145 Thyroid disease; RCOA – 2023 – Endocrine anaesthesia