BCA BCA Neuroanesthesia & Neurosurgical Procedures 2 — Questions and Answers
Question 1: Which volatile anesthetic is MOST likely to increase intracranial pressure at concentrations above 1 MAC?
- Sevoflurane
- Desflurane
- Isoflurane
- All volatile agents have similar ICP effects above 1 MAC (Correct answer)
Correct answer: All volatile agents have similar ICP effects above 1 MAC
All volatile anesthetic agents cause dose-dependent cerebral vasodilation and ICP elevation above 1 MAC; the effect is dose-dependent rather than agent-specific.
Question 2: In a patient with a traumatic brain injury (TBI), the TARGET mean arterial pressure (MAP) to maintain cerebral perfusion pressure (CPP) of at least 60 mmHg with an ICP of 20 mmHg is:
- 60 mmHg
- 70 mmHg
- 80 mmHg (Correct answer)
- 90 mmHg
Correct answer: 80 mmHg
CPP = MAP − ICP; to achieve CPP ≥ 60 mmHg with ICP of 20 mmHg, MAP must be ≥ 80 mmHg.
Question 3: Mannitol reduces intracranial pressure primarily by:
- Inhibiting CSF production
- Creating an osmotic gradient that draws water from brain parenchyma (Correct answer)
- Causing cerebral vasoconstriction
- Blocking sodium channels in neurons
Correct answer: Creating an osmotic gradient that draws water from brain parenchyma
Mannitol establishes an osmotic gradient across the blood–brain barrier, drawing free water from brain tissue into the intravascular space and reducing brain volume.
Question 4: Which neuromuscular blocking agent is CONTRAINDICATED in patients with acute denervation injury (e.g., spinal cord injury within 72 hours)?
- Rocuronium
- Vecuronium
- Cisatracurium
- Succinylcholine (Correct answer)
Correct answer: Succinylcholine
Succinylcholine causes massive potassium release from upregulated acetylcholine receptors in denervated muscle, risking fatal hyperkalemic cardiac arrest.
Question 5: During awake craniotomy for brain mapping, the anesthetic technique that best allows intraoperative neurological testing while maintaining patient comfort is:
- General anesthesia with MEP monitoring
- Asleep-awake-asleep technique with dexmedetomidine/propofol (Correct answer)
- High-dose opioid sedation
- Ketamine-based dissociative anesthesia
Correct answer: Asleep-awake-asleep technique with dexmedetomidine/propofol
The asleep-awake-asleep technique using dexmedetomidine and/or propofol provides sedation during opening/closing while allowing an awake, cooperative patient for cortical mapping.
Question 6: Cerebral autoregulation maintains constant cerebral blood flow (CBF) over a MAP range of approximately:
- 30–60 mmHg
- 50–150 mmHg (Correct answer)
- 70–180 mmHg
- 90–200 mmHg
Correct answer: 50–150 mmHg
Normal cerebral autoregulation maintains constant CBF across a MAP of approximately 50–150 mmHg; outside this range, CBF becomes pressure-passive.
BCA BCA Neuroanesthesia & Neurosurgical Procedures 2
Which volatile anesthetic is MOST likely to increase intracranial pressure at concentrations above 1 MAC?