Standardized EEG interpretation accurately predicts prognosis after cardiac arrest

Publication

Standardized EEG interpretation accurately predicts prognosis after cardiac arrest

Journal Paper/Review - Feb 10, 2016

Westhall Erik, Kjaergaard Jesper, Kuiper Michael, Pellis Tommaso, Stammet Pascal, Wanscher Michael, Wetterslev Jørn, Wise Matt P, Cronberg Tobias, TTM-trial investigators, Fässler Edith, Hovdenes Jan, Hassager Christian, Gasche Yvan, Rossetti Andrea O, van Rootselaar Anne-Fleur, Wesenberg Kjaer Troels, Horn Janneke, Ullén Susann, Friberg Hans, Nielsen Niklas, Rosén Ingmar, Åneman Anders, Erlinge David, Kleger Gian-Reto

Citation

Westhall E, Kjaergaard J, Kuiper M, Pellis T, Stammet P, Wanscher M, Wetterslev J, Wise M, Cronberg T, TTM-trial investigators, Fässler E, Hovdenes J, Hassager C, Gasche Y, Rossetti A, van Rootselaar A, Wesenberg Kjaer T, Horn J, Ullén S, Friberg H, Nielsen N, Rosén I, Åneman A, Erlinge D, Kleger G. Standardized EEG interpretation accurately predicts prognosis after cardiac arrest. Neurology 2016; 86:1482-90.

Type

Journal Paper/Review (English)

Journal

Neurology 2016; 86

Publication Date

Feb 10, 2016

Issn Electronic

1526-632X

Pages

1482-90

Brief description/objective

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.