Cerebrospinal Fluid Dynamics, Adult Hydrocephalus, Endoscopic Third Ventriculostomy, and Shunt Surgery — WACS Viva & Clinical Scenarios (Neuroanaesthesia)

Exam-style cerebrospinal fluid dynamics, adult hydrocephalus, endoscopic third ventriculostomy, and shunt surgery viva scenarios with examiner probes and model…

Scenarios covered

SCENARIO 1: A 26-year-old woman with obstructive hydrocephalus secondary to aqueductal stenosis is undergoing an endoscopic third ventriculostomy (ETV). While the neurosurgeon is irrigating and fenestrating the floor of the third ventricle with a Fogarty balloon catheter, the patient's heart rate drops suddenly from 82 bpm to 28 bpm, and blood pressure spikes to 200/115 mmHg. Detail your immediate diagnostic reasoning, surgical instructions, and pharmacological resuscitation.
SCENARIO 2: A 72-year-old man with Normal Pressure Hydrocephalus (Hakim-Adams triad) and ischemic heart disease is scheduled for a VP shunt insertion. Brain CT shows ventriculomegaly disproportionate to sulcal enlargement. Describe your anaesthetic assessment, intraoperative management during subcutaneous tunnelling, and precautions to prevent acute subdural haematoma formation from rapid ventricular decompression.
SCENARIO 3: During an ETV in a 34-year-old male, the neurosurgeon notes poor visualization due to choroid plexus bleeding and increases the irrigation rate of warm Ringer's lactate. Five minutes later, the invasive arterial line waveform is flattened, the patient becomes severely hypertensive, heart rate falls to 35 bpm, and the pupil on the side of the endoscope dilates. Explain the pathophysiology of this crisis and your immediate management.
SCENARIO 4: A 40-year-old woman with a history of tuberculous meningitis presents with communicating hydrocephalus and is booked for a VP shunt under general anaesthesia. She has a baseline GCS of 13. Describe your induction, maintenance, fluid therapy, and pain management strategies, including the anaesthetic implications of anti-tuberculous drug interactions.