A 68-year-old man is admitted to the ICU following out-of-hospital cardiac arrest with return of spontaneous circulation after 18 minutes of CPR. After 72 hours of targeted temperature management at 33°C, he remains deeply comatose with absent brainstem reflexes. His EEG shows the pattern marked **A** in the diagram — alternating bursts of high-amplitude polymorphic activity and flat suppression intervals. Which of the following best describes the clinical significance of this EEG finding in the context of post-arrest prognostication?

Question

Accepted Answer

C. It indicates severe anoxic-ischemic encephalopathy and carries a poor prognosis when present after 72 hours of normothermia, necessitating multimodal prognostication before withdrawal of care. ## Why option 1 is correct

Burst suppression (pattern **A**) in the context of post-cardiac arrest anoxic-ischemic encephalopathy after 72 hours of normothermia is a well-established poor prognostic indicator. According to Miller Anesthesia 9e and Adams Neurology 11e, this pattern reflects severe cortical dysfunction and, when present in this clinical timeline, is part of the multimodal prognostication algorithm alongside other ominous markers (myoclonic status, absent N20 SSEPs, neuron-specific enolase >60). The presence of burst suppression in this setting warrants careful prognostication before considering withdrawal of life-sustaining therapy.

## Why each distractor is wrong

- **Option 2**: Burst suppression in post-arrest anoxic injury is NOT an anesthetic target — it is a pathologic finding reflecting irreversible cortical damage. Increasing sedation will not reverse the underlying anoxic injury. Burst suppression is an intentional anesthetic target only in refractory status epilepticus or for cerebral protection during planned procedures (aneurysm clipping, circulatory arrest), not in post-arrest prognostication.

- **Option 3**: Burst suppression post-arrest is never benign or reversible. It represents severe, likely irreversible cortical dysfunction and is associated with poor neurologic outcomes. It does not resolve with rewarming or supportive care alone in the anoxic-ischemic context.

- **Option 4**: Burst suppression is NOT pathognomonic for Ohtahara syndrome. While Ohtahara (early infantile epileptic encephalopathy) does present with burst suppression on EEG in neonates, the clinical context here is a 68-year-old post-arrest patient. Ohtahara requires neonatal onset, tonic spasms, and burst suppression on both wake and sleep EEG — a completely different clinical entity.

**High-Yield:** Burst suppression = deep anesthetic target in refractory status epilepticus; OMINOUS prognostic sign in post-arrest anoxic injury after 72 hours normothermia.

[cite: Miller Anesthesia 9e Ch 50; Adams Neurology 11e Ch 16]

Answer

A. It is pathognomonic for Ohtahara syndrome and mandates immediate initiation of vigabatrin and ACTH therapy for neonatal seizure management

Answer

B. It suggests inadequate sedation depth during therapeutic hypothermia and indicates the need for increased propofol infusion to achieve deeper anesthesia

Answer

D. It represents a benign, reversible finding commonly seen in the first 24 hours post-arrest that typically resolves with continued supportive care and rewarming

Explanation

Practice similar questions