Common Local Anaesthetic and anaesthesia exam questions for medical finals, OSCEs and MRCP PACES
What is the maximum dose, in mg/kg, for the following local anaesthetics?
- Lidocaine (3mg/kg & 7mg/kg adrenaline)
- Bupivicaine (2mg/kg & 3mg/kg adrenaline)
What are the symptoms and signs of local anaesthetic toxicity and how is it managed?
- CNS symptoms & signs: perioral paraesthesiae; tinnitus; twitching; visual disturbances; light-headedness/dizziness; tongue numbness/metallic taste; anxiety; confusion; ‘feeling of impending doom’; seizures with further increased toxicity inhibiting cardiorespiratory centres in the medulla leading to respiratory failure; arrhythmias; cardiac arrest; hypotension; coma; death
- Cardiovascular symptoms & signs: bradycardia; hypotension; arrhythmias; cardiac arrest
- Treatment: Call for help/senior support; ABC management with supplemental oxygen; circulatory support/fluids; ventilation (if required). Consider use of lipid emulsion eg Intralipid™ 20% solution. Consider benzodiazepines for seizures