Brief ReportElectroencephalography findings in patients presenting to the ED for evaluation of seizures☆,☆☆,★
Introduction
An estimated 20 million patients in the United States have epilepsy, and an additional 140 000 patients are diagnosed each year [1]. Up to 20% of epilepsy patients develop status epilepticus in their lifetime. Status epilepticus is a life-threatening condition of prolonged seizures for which treatment is time sensitive. The mortality rates for adult episodes of status epilepticus are between 16% and 25% [2]. Aggressive, early treatment is recommended to reduce neurologic morbidity and mortality [2], [3].
Patients with status epilepticus are often admitted to the hospital through the emergency department (ED) [1], [2]. Approximately 1% to 2% of all ED patients have a chief complaint of seizures, and 7% of these are admitted for suspicion of status epilepticus [4], [5]. The definitive diagnosis of status epilepticus is obtained by an electroencephalogram (EEG) study, interpreted by a trained specialist. The results of the EEG frequently guide therapeutic decision making, especially in the absence of overt clinical seizures [6]. However, EEG monitoring is often delayed until after admission to the hospital, and experience suggests few patients receive an EEG in the ED. This delay may result in either protracted periods of unrecognized or untreated status epilepticus with resultant high morbidity and mortality [2] or overutilization of resources, when patients without status epilepticus are admitted.
It is unknown if acquisition of an EEG during the ED stay would impact the therapeutic decision making and outcomes for patients with suspected status epilepticus [5]. Potential benefits of obtaining an EEG in the ED include early recognition and treatment of confirmed status epilepticus and the expedited workup and disposition of patients with ruled out status epilepticus. Obtaining an EEG in the ED could therefore help optimize resource utilization and decision making for ED patients with suspected status epilepticus.
This study was designed to characterize the pattern of EEG acquisition for patients presenting to the ED with a complaint of seizures who are subsequently admitted to the hospital. We also estimated the proportion of EEGs diagnostic for seizures or status epilepticus as well as the potential impact of obtaining an EEG in the ED on patient outcomes.
Section snippets
Study design and setting
This retrospective chart review was conducted at an urban, academic, tertiary care center with greater than 90 000 annual adult visits to the ED [7]. This study was approved by the institutional review board.
Selection of participants
Eligible patients were identified from electronic medical records using International Classification of Diseases, Ninth Revision (ICD-9) and Current Procedural Terminology (CPT) codes. Potentially eligible patients had a seizure-related ICD-9 code (780.97, 780.39, 345.0, 345.1, 345.2, 345.3,
Characteristics of study subjects
There were 171 patients with an ICD-9 code related to seizures and with a CPT code for an EEG identified. Of these, 51 were excluded: 20 (39%) patients did not have a documented ED physician diagnosis of status epilepticus or seizure, 13 (25%) were transferred from a different facility, 9 (18%) had no EEG obtained within 24 hours of presentation, 7 (14%) left against medical advice, and 2 (4%) had incomplete records. The Figure summarizes patient inclusion.
The mean age of the 120 included
Significance
In patients admitted to the hospital from the ED with suspected seizures or status epilepticus, only 3% with EEG performed within 24 hours had an EEG diagnostic for seizures. Twenty-seven percent of EEGs were performed in the ED. Of these, 6% were diagnostic for seizures, compared with 2% of inpatient EEGs done after admission. Given these rates of occurrence of seizures and status epilepticus after the initial ED course and the finding that 37% of all patients were discharged within 24 hours,
Conclusions
Early EEG acquisition in ED patients with suspected seizures or status epilepticus might identify a group of patients amenable to ED observation and subsequent discharge from the hospital. Future studies should assess the potential impact of routine EEG acquisition in the ED on patient outcomes and resource utilization.
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Cited by (3)
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There are no conflicts of interest from any author, as it pertains to this manuscript.
- ☆☆
This project was funded in part by the National Center for Research Resources and the National Center for Advancing Translational Sciences, National Institutes of Health, through grant 8 UL1 TR000077-05.
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Selected results were presented at the Society for Academic Emergency Medicine Annual Meeting in Dallas, TX, in May 2014.
- 1
With guidance from WAK and OMA, who conceived the study, designed the trial, and obtained research funding.
- 2
Drafted the manuscript, and all authors contributed substantially to its revision.
- 3
Supervised the conduct of the trial and data collection.
- 4
Managed and analyzed the data, including quality control.
- 5
Provided input to the design of the study.
- 6
Provided statistical oversight.
- 7
Takes responsibility for the manuscript as a whole.