S96. EEG reactivity testing practices for cardiac arrest coma prognostication in North America

Introduction Lack of EEG reactivity is associated with unfavorable functional outcome in hypoxic-ischemic brain injury. Recent literature suggests that EEG reactivity inter-rater agreement between experts is as low as 26–50%. It is unclear if technical procedures, nomenclature variability, and practice patterns might contribute to poor inter-rater agreement rates. Methods We conducted a survey of representatives from North American institutions participating in the Critical Care EEG Monitoring Research Consortium to assess practice patterns involving EEG reactivity testing. The 10-question multiple choice survey evaluated center-specific metrics related to technical, personnel, and procedural aspects of EEG reactivity testing and assessment specific to cardiac arrest prognostication. One response per institution was obtained. Results We received responses from 25 institutions, including seven pediatric hospitals. A standardized EEG reactivity testing protocol was available in 44% of centers and 44% of respondents felt that reactivity assessment was subjective. Electroencephalogram reactivity testing usually started during hypothermia (76%) and tipically happened at least once daily (63%). Auditory stimulation and nail bed pressure were the most frequently used stimulation modalities (83% and 63% respectively). One institution included nipple pinching as part of its testing protocol. Stimulation was performed primarily by EEG Technologists (76%). Video-EEG assessment was the most common review method (92%). Changes in EEG amplitude were not considered consistent with EEG reactivity by 24% of centers. Stimulus induced rhythmic, periodic, or ictal discharges were considered indicative of EEG reactivity in 44% of centers. Conclusion There is substantial variability in EEG reactivity testing practices among North American academic medical centers. Lack of standardization of stimulation protocols, training of EEG Technologists, and ambiguous definitions of EEG reactivity might contribute to subjectivity and variability in EEG reactivity assessment.