Nonconvulsive status epilepticus following cardiac arrest—are we missing the beginning?

Abstract

Background: Status epilepticus (SE) is a common complication in patients surviving a cardiac arrest, but little is known about the frequency of nonconvulsive status epilepticus (NCSE). Objectives: To compile the first the evidence from the literature of the overall frequency of NCSE in adults with persistent coma following cardiac arrest. Secondarily, to assess the emergence of NCSE in comatose resuscitated patients within the first hours of the return of spontaneous circulation (ROSC) and before inducing target temperature management. Material and methods: The medical search engine PubMed was screened to identify prospective and retrospective studies in English reporting on the frequency of NCSE in comatose post-resuscitated patients. Study design, time of EEG performance, detection of SE and NCSE, outcomes, and targeted temperature management were assessed. Results: Only three cohort studies (one prospective and two retrospective) reported on the EEG evaluation describing NCSE during ongoing sedation and target temperature management. Overall, we identified 213 patients with SE in 18–38% and NCSE in 5–12%. Our review found no study reporting NCSE in resuscitated adult patients remaining in coma within the first hours of ROSC and prior to targeted temperature management and sedation. Conclusion: Studies of NCSE after ROSC in adults are rare and mostly nonsystematic. This and the low proportion of patients reported having NCSE following ROSC suggest that NCSE before target temperature management and sedation is often overlooked. The limited quality of the data does not allow firm conclusions to be drawn regarding the effects of NCSE on outcome calling for further investigations. Clinicians should suspect NCSE in patients with persistent coma before starting sedation and targeted temperature management.