Local Anaesthetics, Additives, and Local Anaesthetic Systemic Toxicity (LAST) — WACS Viva & Clinical Scenarios (Pharmacology and Applied Pharmacology)

Exam-style local anaesthetics, additives, and local anaesthetic systemic toxicity (last) viva scenarios with examiner probes and model answers for ANAESTHESIA…

Scenarios covered

• SCENARIO 1: A 28-year-old male receives an axillary brachial plexus block with 30 mL of 0.5% plain bupivacaine for tendon repair. Two minutes after injection, he reports perioral numbness and tinnitus, followed immediately by generalized tonic-clonic seizures and wide-complex ventricular tachycardia. Outline your step-by-step emergency pharmacological and supportive management.
• SCENARIO 2: A 35-year-old parturient is scheduled for elective Caesarean delivery. You choose spinal anaesthesia using hyperbaric bupivacaine. Detail the factors governing the baricity, spread, duration, and differential nerve block of local anaesthetic agents in the subarachnoid space.
• SCENARIO 3: A surgical team requests 60 mL of local anaesthetic infiltration for multiple lipoma excisions in a 50 kg female. Calculate the maximum safe doses of lidocaine plain, lidocaine with adrenaline (1:200,000), and bupivacaine plain. Formulate a safe local anaesthetic solution for this patient.
• SCENARIO 4: A 45-year-old male with severe coronary artery disease undergoes supraclavicular nerve block. Defend your choice of ropivacaine or levobupivacaine versus racemic bupivacaine on the basis of stereospecific cardiotoxicity.