P12-S Frontotemporal electrode set for ICU bedside cEEG monitoring for comatose patients after cardiac arrest

Background: Electroencephalogram (EEG) patterns within 24 h after cardiac arrest (CA) have shown to reliably predict neurological outcome. The recording set-up may be simplified by using a less extensive electrode set. We compared a 4-channel frontotemporal EEG headband (BrainStatus, Bittium, Oulu, Finland) to a 9-channel Ag-AgCl electrode set.Material and methods: Between July 2018 and January 2019, EEGs were recorded in 22 consecutive adult patients admitted after CA with both electrode sets simultaneously. EEG patterns were assessed visually, corresponding to the guidelines of the American Clinical Neurophysiology Society (ACNS). Five minute epochs at 24 h after CA were scored by three independent EEG readers blinded to clinical data. Final classification was determined by majority vote. To evaluate classification agreement between the electrode sets, confusion matrices and Cohen’s Kappa were used.Results: At 24 h after CA, the background patterns of 21 patients were available. With the 9 electrode set, nine patients had a continuous pattern, two patients had a discontinuous pattern, two patients showed burst-suppression without identical burst, one patient showed burst-suppression with identical bursts, and four patients had a suppressed background pattern. The background pattern of three patients was obscured by artefacts. The agreement for background pattern scoring of the 4 electrode set compared to this 9 electrode set was fair ( = 0.32).Conclusions: Visual classification of EEG patterns in patients with postanoxic coma with a 9-channel Ag-AgCl electrode set cannot be replaced with a 4-channel frontotemporal EEG headband