Brachial Plexus Anatomy and Upper Extremity Nerve Blocks — WACS Viva & Clinical Scenarios (Anatomy, Applied Anatomy and Regional Anaesthesia)

Exam-style brachial plexus anatomy and upper extremity nerve blocks viva scenarios with examiner probes and model answers for ANAESTHESIA candidates.

Scenarios covered

• SCENARIO 1: A 45-year-old male with a history of severe bullous emphysema sustained a comminuted right humeral head fracture following a road traffic collision. You plan an interscalene brachial plexus block for open reduction and internal fixation. Explain the precise sonographic and surface anatomy of the interscalene groove, the structures at risk, and your strategy to manage or avoid ipsilateral phrenic nerve paresis.
• SCENARIO 2: A 30-year-old female presents for urgent open reduction and internal fixation of a distal radius fracture. You perform an ultrasound-guided supraclavicular brachial plexus block. Twenty minutes following the injection of 25 mL of 0.5% bupivacaine, she develops sudden shortness of breath, ipsilateral chest tightness, and a dry cough. Detail your diagnostic differential, immediate anatomical reasoning, and acute anaesthetic intervention.
• SCENARIO 3: A 58-year-old male with poorly controlled type 2 diabetes presents for emergency drainage of a deep palmar space abscess and debridement of the right hand. Ultrasound is unavailable. Describe the landmark-guided technique for an axillary brachial plexus block and supplemental peripheral blocks, identifying every anatomical structure traversed and the specific motor responses elicited if a peripheral nerve stimulator is utilized.
• SCENARIO 4: A 22-year-old motorcyclist sustains an open midshaft forearm fracture. An infraclavicular brachial plexus block is chosen. Detail the anatomical boundaries of the infraclavicular fossa, the relationship of the cords to the axillary artery and vein, the puncture approach (coracoid versus costoclavicular), and how this technique minimizes the risk of phrenic nerve blockade.
• SCENARIO 5: A 40-year-old carpenter undergoes elective tendon repair of the right thumb under an axillary brachial plexus block. Intraoperatively, during surgical manipulation on the lateral aspect of the forearm and thenar eminence, the patient complains of sharp pain. Explain the anatomical basis for this sensory sparing and describe the exact rescue block required to achieve complete surgical anaesthesia.