Abstracts

Rationale: Cooling has been found to be beneficial following cardio-pulmonary arrest (CPA). At our institution, a cooling protocol is instituted following CPA. Clinical exam and imaging studies are of limited benefit in assessing early prognosis in these patients. Continuous video-EEG (cVEEG) is often obtained in these patients for concern of seizures especially subclinical seizures since the patients need to be paralyzed. However, there is limited data on EEG findings during and following the cooling protocol and its correlation with clinical outcomes. We therefore investigated EEG findings and it s potential utility for early prognostication.Methods: We reviewed consecutive cases from the University of Colorado Hospital from January to June of 2011 and identified patients who underwent the cooling protocol status post cardiac or pulmonary arrest and had cVEEG s done. Patients were cooled for 24 hours, during which time they were paralyzed and sedated. Following cooling, patients were re-warmed over 12 hours. Continuous video-EEGs were recorded during the cooling phase and continued for approximately 12 hours post warming. Outcomes were defined as good, indicating discharge to home or rehab, or poor, signifying withdrawal of care and death.Results: There were 12 patients identified. All patients were resuscitated and placed on a cooling protocol following cardiac arrest. Continuous video-EEG recordings showed a variety of patterns during and after the cooling and re-warming phases of the protocol. There were 5 patients with good outcome and 7 patients with poor outcome. The predominant pattern during the cooling was a suppressed background with limited activity. There were correlations between the post cooling EEG findings and clinical outcomes in these patients. EEG findings associated with a good outcome and meaningful recovery included a continuous pattern with slow or mixed frequencies, reactivity , and improvement in the EEG during and following the re-warming phase. EEG findings associated with poor outcome included the presence of generalized periodic epileptiform discharges, seizures, a suppressed pattern, a burst-suppression pattern, and discontinuity with suppression and slowing. These EEG findings were seen within 48 hours of the initiation of the cooling protocol.Conclusions: Cooling is thought to be beneficial following CPA. However, it is often difficult to assess early who will have a favorable outcome from the limited clinical exam and imaging studies available. We looked at the cVEEG of patients in a cooling protocol following CPA and its correlation with clinical outcome. Our results provide initial evidence that distinct patterns on the EEG can provide early prognostic information on patients undergoing cooling protocol following CPA.