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Local anaesthetic toxicity — NDEB AFK MCQ

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HardBiomedical SciencesLocal anaesthetic toxicityNDEB AFK

A 58-year-old patient weighing 52 kg requires extraction of tooth 3.6. After four cartridges of 2% lidocaine with epinephrine 1:100,000, the patient becomes restless, reports circumoral tingling, and develops tremor. What is the most likely cause/mechanism?

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Correct answer: B — Excess systemic lidocaine exposure

The neurological symptoms after multiple cartridges in a low-weight adult are most consistent with systemic local anaesthetic toxicity from lidocaine exposure. Intravascular epinephrine can cause palpitations and tremor, but circumoral tingling and progressive neurological excitation point more strongly to anaesthetic toxicity. The practical pearl is to calculate maximum dose by weight before repeated cartridges, especially in small adults or medically complex patients.

Reference: NDEB KSAs 2024; CDA dental pharmacology reference texts