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Topical Lidocaine Maximum Dose Airway — FRCA Final MCQ

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ModerateAirway ManagementTopical Lidocaine Maximum Dose AirwayFRCA Final

A 50-year-old woman (ASA II) is undergoing an awake fibreoptic intubation for a predicted difficult airway. After topicalisation of the airway with 4% lidocaine via spray-as-you-go technique, the total lidocaine dose used is 320 mg. Her weight is 60 kg. The maximum dose of lidocaine for topical airway anaesthesia is:

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Correct answer: B — 9 mg/kg (540 mg)

For topical airway application (as opposed to injection), lidocaine has a higher maximum recommended dose of up to 9 mg/kg. This is because topical mucosal absorption is slower and less complete than injection, resulting in lower peak plasma levels. The British Thoracic Society recommends up to 8.2 mg/kg for bronchoscopy topicalisation. The dose of 320 mg (5.3 mg/kg) is well within the safe topical range. However, absorption can be enhanced by inflamed or ulcerated mucosa, and caution should be exercised in patients with liver disease or low body weight.

Reference: DAS – 2020 – Awake tracheal intubation guidelines; BTS – 2013 – Bronchoscopy guidelines; BNF – 2025