Abstract
This study reviews protocols for treating convulsive status epilepticus from 33 emergency medical services systems in California to determine if they had incorporated updated evidence-based guidelines.
Multiple forms of status epilepticus exist (absence, focal, nonconvulsive) but generalized convulsive status epilepticus is most common and represents a neurological emergency. Two double-blind, randomized clinical trials (published 2001 and 2012) demonstrated the efficacy of benzodiazepines for the prehospital treatment of generalized convulsive status epilepticus.1,2
A 2016 evidence-based guideline that incorporated the findings from these trials cited level A evidence for intramuscular midazolam, intravenous lorazepam, or intravenous diazepam as initial treatment options in adults.3 We determined whether evidence-based recommendations have been incorporated into current emergency medical services (EMS) system protocols.
Methods
Treatment protocols for adult patients presenting with seizures from 33 EMS systems covering the 58 counties in California were accessed online and reviewed by 2 of the authors (J.P.B. and E.L.G.) between May and June 2018 without disagreements. The protocols were reviewed to determine (1) when they were last updated in relation to the prehospital treatment studies and 2016 guideline and (2) whether generalized convulsive status epilepticus was defined in strict accordance with the definition referenced in the guidelines (≥5 minutes of continuous seizure or ≥2 discrete seizures between which there is incomplete recovery of consciousness).3,4
We determined if any of the 3 studied benzodiazepines were included in the protocols along with the route of administration and dose. In an effort to be inclusive, we compared the EMS system protocols with the range of doses studied in the randomized clinical trials, which were incorporated into the guideline recommendations, recognizing that some EMS system protocols have not been updated since the 2016 guideline was published and may have based their dosing from clinical trial data.
Results
The most recent revision date for the protocols from the 33 EMS systems ranged from 2007 to 2018 with 27 (81.8%) revised after publication of the second clinical trial in 2012 and 17 (51.5%) revised after publication of the guideline in 2016 (Table). Seven EMS system protocols (21.2%) defined generalized convulsive status epilepticus according to published guidelines. Thirty-two EMS system protocols (97.0%) included intramuscular midazolam; 2 (6.1%), intravenous lorazepam; and 5 (15.2%), intravenous diazepam.
Table. Protocol Characteristics for Generalized Convulsive Status Epilepticus in Adults Treated at Emergency Medical Services Systems in California.
| Protocol Characteristics | No. (%) (N = 33) |
|---|---|
| Updated after December 31, 2012a | 27 (81.8) |
| Updated after December 31, 2016b | 17 (51.5) |
| Defined generalized convulsive status epilepticus according to AES or ILAE guidelinesc | 7 (21.2) |
| Midazolam, intramuscular | 32 (97.0) |
| Dose matches guidelinesd | 2 (6.1) |
| Lorazepam, intravenous | 2 (6.1) |
| Dose matches guidelinese | 2 (6.1) |
| Diazepam, intravenous | 5 (15.2) |
| Dose matches guidelinesf | 2 (6.1) |
| Recommended ≥1 medications by route and dose suggested in trials or guidelines | 6 (18.2) |
Abbreviations: AES, American Epilepsy Society; ILAE, International League Against Epilepsy.
The 2 randomized clinical trials were published in 2001 (Prehospital Treatment of Status Epilepticus trial; PHTSE) and 2012 (Rapid Anticonvulsant Medication Prior to Arrival Trial; RAMPART).
The AES guideline was published in 2016.
Definitions include 5 minutes or more of continuous seizure or 2 or more discrete seizures between which there is incomplete recovery of consciousness.3,4
RAMPART and AES guideline recommend 10 mg administered intramuscularly in adults who weigh more than 40 kg.
Thirty-two EMS system protocols (97.0%) listed intravenous midazolam and 16 (48.5%) listed intraosseous midazolam as options. Two EMS system protocols recommended an initial dose of intramuscular midazolam of 10 mg in accordance with clinical trial data, whereas 30 recommended a lower initial dose. Both of the protocols that included intravenous lorazepam recommended doses in accordance with trial data (2-4 mg).
Two of 5 EMS system protocols that included diazepam recommended a dose in agreement with trial data or published guidelines (5-10 mg). Six EMS system protocols (18.2%) recommended at least 1 of the medications by the route and dose suggested in the trials or in the guidelines.
Discussion
California EMS system protocols varied widely with regard to the definition and treatment of generalized convulsive status epilepticus. Many protocols did not follow evidence-based guidelines and did not accurately define generalized convulsive status epilepticus.
Although intramuscular midazolam was appropriately emphasized in the protocols, the dose was often lower than recommended. Most protocols listed intravenous and intraosseous midazolam as options, which were not studied in the randomized clinical trials or recommended in the guideline. Appropriate dosing and route of administration is critical in achieving timely cessation of generalized convulsive status epilepticus.
This study underscores the challenge of translating evidence to implementation in the prehospital setting. Why EMS system protocols deviate from the evidence and how this affects patient outcomes deserve further study.5
Potential reasons for not incorporating current evidence include difficulty transferring information from trials or guidelines to protocols, systematic issues updating EMS system protocols, coordination of stakeholder organizations, and limited awareness about the harm of insufficient benzodiazepine dosing.6 An initial step would be to ensure EMS system protocols differentiate between a seizure and generalized convulsive status epilepticus and that the definition is standardized across protocols.
Limitations of the study include investigation of EMS system protocols from a single state and protocols may not necessarily reflect what emergency medical technicians actually do in practice. Emergency medical services systems were not contacted for their most updated protocols; rather, the most recent protocol available on each system’s website was used.
Section Editor: Jody W. Zylke, MD, Deputy Editor.
References
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