Abstracts

Rationale: Greater than 500, 000 children and adults go into cardiac arrest each year in the United States (1,2). It has been noted that ~12% of all patients that have received therapeutic hypothermia are also in subclinical status epilepticus (2). It is known that continuous EEG (cEEG) monitoring helps with seizure detection and prognosis for post-cardiac arrest patients. However, there is limited data on the optimal length of cEEG monitoring and how to prioritize EEGs when there are few resources. It is important to assess these questions to provide ideal care.

Methods: This was a retrospective chart review in which all post-cardiac arrest adult patients that have undergone cEEG monitoring from January 2019 to January 2020 were reviewed. Basic demographic data, details of the admission, and end outcomes were collected. The cEEG monitoring reports were also reviewed to determine post-anoxic EEG patterns, frequency of seizures, and at what time points each of the above occurred. Raw EEG data was reviewed in specific situations.>

Results: There were a total of 164 patients that were reviewed. Of those 164 patients, 26 of those patients (16%) had seizures. Sixty-nine percent of those patients (18/26) had seizures at the start of cEEG monitoring, 85% of patients (22/26) had seizures within the first 24 hours of recording, and 96% of patients (25/26) had seizures within the first 48 hours of recording. Furthermore, our results demonstrated that 40% of patients (66/164) were monitored for greater than 48 hours.

In terms of our secondary outcomes, 81% of patients that had seizures had clinical symptoms prior to cEEG monitoring that exclusively consisted of myoclonus. There was a higher percentage of mortality among those that underwent targeted therapeutic monitoring (TTM) compared to those that did not undergo TTM but this relationship was not statistically significant. Both groups (TTM and non-TTM) had a similar frequency of seizures.

Conclusions: Based on our results, 48 hours of cEEG monitoring is an ideal amount of time for the screening of seizures in post-cardiac arrest patients. In our institution, 40% of patients were monitored for more than 48 hours suggesting that cEEG monitoring often extends further than what may be necessary. If there are limited resources at an institution, a routine (30 minute) EEG would be an adequate screening tool as almost 70% of patients had seizures at the onset of EEG recording. Additionally, patients that are having any clinical signs of myoclonus should be prioritized over those that do not have clinical symptoms. Finally, we found no major difference in seizure frequency from those that underwent TTM and those that did not.

Funding: Please list any funding that was received in support of this abstract.: There was no specific funding for this project.