Continuous EEG Monitoring and Clinical Outcomes in Patients Undergoing ECMO

Background Neurological complications during Extracorporeal membrane oxygenation (ECMO) can result in long-term cognitive deficits. This exploratory study aimed to determine the association between continuous EEG (cEEG) findings and neurological outcome in adult patients undergoing ECMO, Methods This retrospective cohort study analyzed EEG characteristics, and clinical outcomes in adult ECMO patients at a tertiary care center. We included all adult ECMO patients from January 1, 2015, to July 31, 2019 including patients in whom cEEG was initiated ASAP with ECMO orders. EEG data were evaluated for association with clinical outcome. Clinical outcomes were assessed using the Glasgow Outcome Scale (GOS), modified Rankin Scale (mRS), and Cerebral Performance Category (CPC) scale at discharge and 6 months. Results Among 329 ECMO encounters, 214 (65%) included cEEG monitoring. Low EEG voltage was associated with poor outcome (CPC, 52.4% vs 64% p = 0.001). EEG reactivity was associated with outcome at 6 months (CPC, 54.8% reactive and good outcome vs 67% unreactive and poor outcomes p = 0.005). The presence of predominant background frequency, normal voltage, was associated with good outcome while higher Mayo EEG grade with poor outcomes. In the limited subset of patients with Sequential Organ Failure Assessment (SOFA) Score, no significant differences were noted between patients with different Mayo EEG grades, EEG reactivity, or background changes. Higher SOFA scores were associated with poor outcomes. Conclusions cEEG monitoring may provide prognostic information for adult ECMO patients. It remains unclear if the EEG findings are solely reflective of underlying severity of illness or not.