Simplified frontal EEG in adults under veno-arterial extracorporeal membrane oxygenation

• Main Authors: Cyril Touchard, Jérôme Cartailler, Geoffroy Vellieux, Etienne de Montmollin, Pierre Jaquet, Ruben Wanono, Jean Reuter, Marylou Para, Lila Bouadma, Jean-François Timsit, Marie-Pia d’Ortho, Nathalie Kubis, Anny Rouvel Tallec, Romain Sonneville, The DINAMO Study Group
• Format: Article
• Language: English
• Published: SpringerOpen 2021-05-01
• Series: Annals of Intensive Care
• Subjects: Frontal EEG; Critical care EEG; Extracorporeal membrane oxygenation; Outcome
• Online Access: https://doi.org/10.1186/s13613-021-00854-0

Abstract Background EEG-based prognostication studies in intensive care units often rely on a standard 21-electrode montage (stdEEG) requiring substantial human, technical, and financial resources. We here evaluate whether a simplified 4-frontal electrode montage (4-frontEEG) can detect EEG patterns associated with poor outcomes in adult patients under veno-arterial extracorporeal membrane oxygenation (VA-ECMO). Methods We conducted a reanalysis of EEG data from a prospective cohort on 118 adult patients under VA-ECMO, in whom EEG was performed on admission to intensive care. EEG patterns of interest included background rhythm, discontinuity, reactivity, and the Synek’s score. They were all reassessed by an intensivist on a 4-frontEEG montage, whose analysis was then compared to an expert’s interpretation made on stdEEG recordings. The main outcome measure was the degree of correlation between 4-frontEEG and stdEEG montages to identify EEG patterns of interest. The performance of the Synek scores calculated on 4-frontEEG and stdEEG montage to predict outcomes (i.e., 28-day mortality and 90-day Rankin score $${\ge {4}}$$ ≥ 4 ) was investigated in a secondary exploratory analysis. Results The detection of EEG patterns using 4-frontEEG was statistically similar to that of stdEEG for background rhythm (Spearman rank test, ρ = 0.66, p < 0.001), discontinuity (Cohen’s kappa,  $$\kappa$$ κ  = 0.955), reactivity ( $$\kappa$$ κ  = 0.739) and the Synek’s score (ρ = 0.794, p < 0.001). Using the Synek classification, we found similar performances between 4-frontEEG and stdEEG montages in predicting 28-day mortality (AUC 4-frontEEG 0.71, AUC stdEEG 0.68) and for 90-day poor neurologic outcome (AUC 4-frontEEG 0.71, AUC stdEEG 0.66). An exploratory analysis confirmed that the Synek scores determined by 4 or 21 electrodes were independently associated with 28-day mortality and poor 90-day functional outcome. Conclusion In adult patients under VA-ECMO, a simplified 4-frontal electrode EEG montage interpreted by an intensivist, detected common EEG patterns associated with poor outcomes, with a performance similar to that of a standard EEG montage interpreted by expert neurophysiologists. This simplified montage could be implemented as part of a multimodal evaluation for bedside prognostication.