Abstracts

Rationale: Therapeutic Hypothermia (TH) is now considered a standard of care in post cardiac arrest (post CA) patients and has been shown to improve survival and neurological outcomes. Continuous electroencephalogram (cEEG) monitoring is an essential part of TH and should be started within a few hours from initiation and continue until a normothermic state is achieved. cEEG monitoring of patients who are comatose and under neuromuscular paralysis is important in order to assess for abnormal EEG patterns including seizures which might indicate a worse prognosis. The purpose of this study is to assess the correlation between EEG patterns during TH with the neurological outcomes of post CA patients. Methods: We retrospectively reviewed the medical records of 20 post CA patients admitted to Stony Brook University Hospital from March 2013 to August 2013 who were placed on TH with cEEG monitoring. EEG reports were reviewed from the time of initiation of TH until restoration of normothermia. EEG patterns found included voltage attenuation, generalized slowing activity, burst-suppression pattern and seizure/epileptiform discharges. These findings were correlated with mortality and overall neurological outcomes of the patients. Poor outcomes were defined as death and good outcomes were defined as full recovery or minimal neurological deficits that allowed discharge. Results: A total of 20 patients (15 men and 5 women) were included. Mean age was 64. All patients were placed on cEEG after initiation of TH. All 20 patients remained on cEEG during the entire duration of TH. A burst-suppression pattern was identified in 4/20 (20%) of patients, all of them died. Generalized periodic discharges with diffuse background slowing was noted in one patient 1/20 (5%) who died One patient 1/20 (5%) had a severely attenuated EEG without any clear cerebral activity and died. A total of 5/20 (25%) patients had a low voltage EEG and died. There were 6/20 (30%) patients with generalized slowing on cEEG. Of those, 4 patients were discharged to a rehabilitation facility, one was discharged home and one died. 3/20 (15%) patients had a normal sedated EEG, all recovered without neurological deficits. Of the 12/20 patients (60%) who died, none had a normal EEG pattern. The remaining 8/20 (40%) patients who were discharged home or to a rehabilitation facility had less severe EEG patterns. Conclusions: Continuous EEG monitoring during TH after cardiac arrest can potentially play a role in predicting neurological outcome. EEG findings such as a burst-suppression pattern or generalized periodic discharges during therapeutic hypothermia forecast poor outcomes and are associated with a higher degree of mortality.