During surgery for an intracranial aneurysm, temporary clip occlusion is planned for up to 20 minutes. Which pharmacological strategy provides the BEST cerebral protection during this period of focal ischaemia?
- A Nimodipine infusion to prevent vasospasm
- B Induced mild hypothermia to 33°C
- C Mannitol 1 g/kg to reduce brain bulk and improve exposure
- D EEG burst suppression with high-dose propofol or barbiturates ✓
Explanation
EEG burst suppression achieved with propofol or barbiturate loading reduces CMRO2 by 50–60%, maximising the brain's tolerance to temporary ischaemia during clip application. By suppressing neuronal electrical activity to silence, oxygen demand falls substantially, extending the window of tolerance for focal ischaemia. Nimodipine is used prophylactically for vasospasm after SAH, not for intraoperative ischaemia. Intraoperative hypothermia to 33°C (IHAST trial) did not improve outcomes versus normothermia. Mannitol aids brain relaxation but does not protect against ischaemia.
Reference: Morgan & Mikhail's Clinical Anesthesiology, 6th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.