S94. Stability of early EEG background patterns after pediatric cardiac arrest

Abstract

Introduction We aimed to determine whether EEG background characteristics remain stable across discrete time periods during the acute period after resuscitation from pediatric cardiac arrest. Methods Children resuscitated from cardiac arrest underwent continuous conventional EEG monitoring. The EEG was scored in 12-h epochs for up to 72-h after return of circulation by an electroencephalographer using a Background Category with four-levels (normal, slow-disorganized, discontinuous/burst-suppression, or attenuated-featureless) or two-levels (normal/slow-disorganized or discontinuous/burst-suppression/attenuated-featureless). Survival analyses and mixed-effects ordinal logistic regression models evaluated whether the EEG remained stable across epochs. Results EEG monitoring was performed in 89 consecutive children. When EEG was assessed as the four-level Background Category 30% of subjects changed category over time. Based on initial Background Category, one quarter of subjects changed EEG category by 24 h if the initial EEG was attenuated-featureless, by 36 h if the initial EEG was discontinuous or burst-suppression, by 48 h if the initial EEG was slow-disorganized, and never if the initial EEG was normal. However, regression modeling for the four-level Background Category indicated that the EEG did not change over time (OR = 1.06, 95%CI = 0.96– 1.17, p = 0.26). Similarly, when EEG was assessed as the two-level Background Category, 8% of subjects changed EEG category over time. However, regression modeling for the two-level category indicated that the EEG did not change over time (OR = 1.02, 95%CI = 0.91–1.13, p = 0.75). Conclusion The EEG Background Category changes over time whether analyzed as four-levels (30% of subjects) or two-levels (8% of subjects) although regression analyses indicated no significant changes occurred over time for the full cohort. These data indicate that the Background Category is often stable during the acute 72 h after pediatric cardiac arrest and thus may be a useful EEG assessment metric in future studies, but that some subjects do have EEG changes over time and therefore serial EEG assessments may be informative.