Background: Evaluation of prognostic value of electroencephalography (EEG) and somatosensory evoked potentials (SEP) according to different recording times.
Methods: A retrospective cohort study performed at the medical ICU of the AOU Careggi Teaching Hospital (Florence, Italy) of comatose adults (>18 years) after cardiac arrest (CA) and treated with therapeutic hypothermia (TH). We evaluated the Glasgow Coma Scale, EEG, and SEP performed at 12, 24, and 72 hrs after CA. Outcome was determined by the Glasgow Outcome Scale at 6 months after CA.
Results: We analyzed 167 patients. All patients with grade 1 EEG ("continuous") within 12 hours of CA recovered consciousness (false positive rate: 0.0%). Grade 2 EEG ("non-continuous") at 72 hours predicted a poor outcome with FPR=0.0%. Bilateral absent SEP at any time after CA predicted a poor outcome.
Conclusions: EEG is a reliable time-dependent predictor of a good outcome (within 12 hours) and a poor outcome (after 72 hours). SEP is a time-independent predictor of a poor outcome.