(593) Rapid-Response EEG in Post-Cardiac Arrest Patients

Introduction: Contemporary recommendations, such as those from the American Heart Association (AHA), emphasize the importance of early electroencephalogram (EEG) in patients who achieve return of spontaneous circulation (ROSC) after cardiac arrest, due to high prevalence of non-convulsive seizures (NCS). Delay in seizure treatment and extended seizure duration portend poor clinical outcomes. The emergence of rapid response EEG (rEEG, Ceribell Inc) technology offers rapid application of continuous monitoring that aids in the early detection of NCS and highly epileptiform patterns (HEP), such as lateralized periodic discharges (LPD), generalized periodic discharges (GPD), and triphasic waves (TP).

Methods: Implementation of rEEG followed a multidisciplinary institutional protocol. rEEG was applied in place of conventional EEG (cEEG) during non-business hours. Automated detection of seizure burden (calculated as the percentage of ten-second epochs with detected seizure activity in any 5-min rEEG segment) was performed using the proprietary Claritγ algorithm. A calculated seizure burden of ≥ 90% suggested ≥ 4.5 min of seizure activity and triggered a status epilepticus alert; treatment was administered accordingly. 10-90 % burden prompted immediate on-call epileptologist review. < 10 % seizure burden suggested against NCS and thus interval epileptology reading was followed. All rEEG recordings underwent daily epileptologist review, and this interpretation served as formal diagnostic standard.

Results: A total of 42 rEEGs were performed between 09/2020 and 05/2023 for an average duration of 9.0 (0.3) hours. Patients had an average age of 64 (15) years and 52% were male. Average APACHE III scores and acute physiologic scores were 54 (27) and 41(23) respectively. NCS was detected in 4 patients (9.5 %), LPD in 2 (4.8 %), GPD in 2 (4.8 %), and TP in 4 (9.5 %). rEEG was followed by cEEG in 41 patients (98%), with following readings: NCS in 7 %, LPD in 17 %, GPD in 56 %, and TP in 61 %.

Conclusions: Detection of NCS in nearly 10% of post-cardiac patients on rEEG and the reemergence of this finding in 7% after cEEG application indicates rEEG may offer meaningful improvement in diagnostic timeliness in this population. Larger sample sizes and evaluation of patient centered outcomes are needed going forward.