ICU · Neurocritical Care
Post-cardiac arrest prognostication
Also known as Post-arrest prognostication · Neurological outcome prediction · Somatosensory evoked potentials (SSEP) · Neuron-specific enolase (NSE)
Prognostication after cardiac arrest predicts neurological outcome to guide continuation or withdrawal of life-sustaining therapy. The key principle: use a MULTIMODAL approach — no single test is 100% reliable. Timing: do NOT prognosticate before 72h post-arrest. Must be: normothermic (no fever for 72h), off sedatives for adequate washout, off NMBAs, no severe metabolic derangement. Assessment tools: (1) Clinical examination (brainstem reflexes, motor response, myoclonus), (2) Electrophysiology (SSEP N20, EEG), (3) Biomarkers (NSE), (4) Imaging (CT/MRI brain). The most reliable single indicator: bilateral absence of N20 response on SSEP (positive predictive value for poor outcome 95%). Goal: accurate, honest, compassionate prognostication for families.
Checked against its sources on 11 Sept 2026
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Target exams
Red flags
- Do NOT prognosticate before 72h post-arrest — wait for sedative washout and normothermia
- No single test is 100% reliable — use MULTIMODAL approach (clinical + SSEP + EEG + biomarkers + imaging)
- Bilateral absence of N20 on SSEP = most reliable single predictor of poor outcome (PPV >95%)
- False positives exist — over-pessimistic prognostication leads to inappropriate withdrawal of life-sustaining therapy
Meet the patient
A 58-year-old man is admitted to the ICU after an out-of-hospital VF cardiac arrest (bystander CPR, defibrillated at 12 minutes, ROSC at 18 minutes). He received targeted temperature management at 36 degrees for 24 hours and is now normothermic; sedation (propofol plus fentanyl) has been off for 36 hours. At 72 hours post-ROSC he is intubated, with no purposeful response to pain, brainstem reflexes intact, and intermittent right-arm myoclonus. The family ask about his prognosis.[1]
Two rules. Never prognosticate before the prerequisites are met (72 hours, normothermia, sedation off, confounders cleared), and never withdraw on a single test — require concordance of two or more major predictors. The myoclonus and the intact brainstem reflexes are a discordant picture; the correct response is to complete the multimodal assessment and wait, not to conclude.[1]
References7ShowHide
- [1]Sandroni C, Cariou A, et al. Prognostication in comatose survivors of cardiac arrest: an advisory statement from the European Resuscitation Council and the European Society of Intensive Care Medicine. Resuscitation, 2014.PMID 25438253
- [2]Nielsen N, Wetterslev J, et al. Targeted temperature management at 33°C versus 36°C after cardiac arrest. N Engl J Med, 2013.PMID 24237006
- [3]Dankiewicz J, et al. Hypothermia versus Normothermia after Out-of-Hospital Cardiac Arrest N Engl J Med, 2021.PMID 34133859
- [4]Perkins GD, Ji C, et al. A Randomized Trial of Epinephrine in Out-of-Hospital Cardiac Arrest. N Engl J Med, 2018.PMID 30021076
- [5]Nolan JP, Sandroni C, Böttiger BW, et al. European Resuscitation Council and European Society of Intensive Care Medicine guidelines 2021: post-resuscitation care. Intensive Care Med, 2021.PMID 33765189
- [6]Lascarrou JB, Merdji H, Le Gouge A, et al. Targeted Temperature Management for Cardiac Arrest with Nonshockable Rhythm. N Engl J Med, 2019.PMID 31577396
- [7]Westhall E, Rossetti AO, van Rootselaar AF, et al. Standardized EEG interpretation accurately predicts prognosis after cardiac arrest. Neurology, 2016.PMID 26865516