Abstract
Objective: To identify reliable predictors of outcome in comatose patients after cardiac arrest using a single routine EEG and standardized interpretation according to the terminology proposed by the American Clinical Neurophysiology Society.
Methods: In this cohort study, 4 EEG specialists, blinded to outcome, evaluated prospectively recorded EEGs in the Target Temperature Management trial (TTM trial) that randomized patients to 33°C vs 36°C. Routine EEG was performed in patients still comatose after rewarming. EEGs were classified into highly malignant (suppression, suppression with periodic discharges, burst-suppression), malignant (periodic or rhythmic patterns, pathological or nonreactive background), and benign EEG (absence of malignant features). Poor outcome was defined as best Cerebral Performance Category score 3–5 until 180 days.
Results: Eight TTM sites randomized 202 patients. EEGs were recorded in 103 patients at a median 77 hours after cardiac arrest; 37% had a highly malignant EEG and all had a poor outcome (specificity 100%, sensitivity 50%). Any malignant EEG feature had a low specificity to predict poor prognosis (48%) but if 2 malignant EEG features were present specificity increased to 96% (p < 0.001). Specificity and sensitivity were not significantly affected by targeted temperature or sedation. A benign EEG was found in 1% of the patients with a poor outcome.
Conclusions: Highly malignant EEG after rewarming reliably predicted poor outcome in half of patients without false predictions. An isolated finding of a single malignant feature did not predict poor outcome whereas a benign EEG was highly predictive of a good outcome.
GLOSSARY
- ACNS=
- American Clinical Neurophysiology Society;
- CPC=
- Cerebral Performance Category scale;
- CI=
- confidence intervals;
- SSEP=
- somatosensory evoked potentials;
- TTM=
- Target Temperature Management;
- WLST=
- withdrawal of life-sustaining therapy
Footnotes
Go to Neurology.org for full disclosures. Funding information and disclosures deemed relevant by the authors, if any, are provided at the end of the article. The Article Processing Charge was paid by the Swedish Research Council.
Coinvestigators are listed on the Neurology® Web site at Neurology.org.
Supplemental data at Neurology.org
Editorial, page 1470
- Received September 7, 2015.
- Accepted in final form December 1, 2015.
- © 2016 American Academy of Neurology
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Disputes & Debates: Rapid online correspondence
- Author reply to Dr. Sethi re prognostic value of sleep transients after cardiac arrest
- Routine EEG predictors of outcome in comatose patients after cardiac arrest
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