An epidural catheter is placed at L2–L3 for post-operative analgesia. The patient suddenly develops loss of consciousness, severe hypotension, and ventricular fibrillation after a test dose. The most likely cause and immediate priority treatment are:

• A Total spinal; immediate airway securing
• B Vasovagal syncope; Trendelenburg position
• C Anaphylaxis; adrenaline 1 mg IV
• D Intravenous local anaesthetic (LA) injection; lipid emulsion 20% 1.5 mL/kg IV bolus ✓

Explanation

The scenario describes systemic local anaesthetic toxicity (LAST) from accidental intravascular injection. Cardiac manifestations (arrhythmia including VF, cardiac arrest) are the most life-threatening feature and can occur rapidly. The primary treatment is 20% intralipid (lipid emulsion) — 1.5 mL/kg IV bolus over 1 minute, followed by infusion at 0.25 mL/kg/min. Cardiopulmonary resuscitation follows ACLS protocol modified to avoid vasopressin, beta-blockers, and calcium channel blockers. Bupivacaine causes more cardiotoxicity than lignocaine or ropivacaine due to greater sodium channel blockade.

Reference: Morgan & Mikhail's Clinical Anesthesiology, 6th ed.

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Written and medically reviewed by the StethoPrep medical team.