Status Epilepticus and Wingardium Leviosa Twitter/Instagram: @emboardbombs
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Authors: Tamir Zitelny, MS4; Blake Briggs, MD; Mary Claire O’Brien, MD
Introduction
Status epilepticus is defined as one seizure episode lasting >30 minutes or multiple seizure episodes without a
return to neurologic baseline/consciousness.1 Given the risks associated with this medical emergency, intervention should not be
delayed. In this guide, we will focus on the approach to convulsive status epilepticus (CSE) in adults, a common form of status
epilepticus, and the neurological sequela we look to avoid with prompt treatment.
Causes of status epilepticus
In patients without any prior diagnosis of epilepsy, the most common causes of CSE include an acute or subacute underlying cerebral
pathology (such as a structural lesion, intracranial infection, stroke, or head trauma), a toxic/metabolic insult, or a combination of the
two.2 In roughly 10% of these patients, status epilepticus may be the presenting manifestation of an underlying seizure disorder.3 In
patients with a history of epilepsy, one of the most common causes is antiseizure medical nonadherence or subtherapeutic dosing of
these medications.4-6
Presentation
Status epilepticus is a true medical emergency – its approach and consequences are remarkably different from “normal” or
breakthrough seizures. Your approach must be significantly more aggressive.
Patients with CSE will demonstrate generalized, bilateral tonic-clonic movements in the setting of impaired mentation for greater than
5 minutes or will not return to baseline between repeated seizure episodes. This contrasts with other forms of status epilepticus which
may exhibit more focal findings.7 The diagnosis of status epilepticus is clinical. CSE has the highest propensity for critical
complications.7 Patients may demonstrate temporary neurologic deficits during the postictal period between or after seizure episodes
(known as Todd’s paralysis).
When the patient is not seizing, do a solid neurologic exam. Specifically, note the patient’s alertness and orientation and examine for
focal neurologic deficits. While EEG can often be diagnostic for CSE, in the ED setting, EEG should never delay intervention.
Once the patient is no longer seizing, a non-contrast head CT to assess for intracranial pathology is warranted, especially in those who
have a first-time seizure. Consider a lumbar puncture in patients who have a fever and/or risk factors and whose presentation
concerning for meningitis or encephalitis.8 Key lab tests include blood glucose levels, serum electrolytes, BUN, creatinine, WBC, Hgb,
and toxicology studies. In patients with a known seizure disorder, serum levels of prescribed antiseizure medications are also useful in
certain cases to assess for subtherapeutic intake.9-11
Early intubation?
If appropriate, rapid sequence intubation should never be withheld in an unresponsive, obtunded patient. To be clear, most patients
who have an isolated seizure or even status epilepticus do not require intubation. They can often be ventilated and oxygenated during
their seizure with a bag-valve-mask as needed. Most post-ictal patients quickly recover their respiratory drive. However, if there are
signs of apnea and the patient cannot be appropriately ventilated and oxygenated during or immediately after their seizure, intubation
is necessary.
Management
Like clockwork, we begin with addressing the “ABCs”: airway, breathing, and circulation. Some important interventions to keep in
mind include:
• Maintain normoxia (i.e., O2 saturation > 95%)
• Begin transfusions as needed to maintain appropriate electrolyte concentrations
• Administer acetaminophen or cool febrile patients; consider external rewarming in hypothermic patients
• Correct hypoglycemia as needed
The primary goal of management is to halt seizure activity as quickly and safely as possible. This follows an algorithmic approach,
giving supportive care and medications in a stepwise manner, as seen below.
First line medication is a benzodiazepine: diazepam, lorazepam, or midazolam (depending on available IV access).12-13
If unsuccessful after two doses, give an antiseizure medication: valproic acid, levetiracetam, or phenytoin/fosphenytoin.
The choice of medication is often based on whether the patient has a history of seizures and their current antiseizure medication profile.
If a patient with a seizure history is found to be subtherapeutic, a loading dose of their current prescribed medication is appropriate.13
However, a serum antiepileptic medication level is wishful thinking in the ED.14-15 Thankfully, it’s been found that the three
aforementioned medications are equally efficacious, with similar side effect profiles and rates of adverse effects.16 As such, any one of
these medications is an appropriate choice.
Status Epilepticus and Wingardium Leviosa Twitter/Instagram: @emboardbombs
After apparent seizure cessation, EEG (or repeat
EEG if one was performed during the diagnostic
process) is often useful to evaluate for CSE
conversion to continued nonconvulsive seizures,
particularly in patients whose mental status does
not improve despite cessation of apparent
seizure activity.17
Rapid seizure abortion in these patients is
crucial. There is an indirect relationship between
length of seizure activity and response to
antiseizure medications. With delayed
intervention, there is a risk for refractory status
epilepticus (RSE), defined not by duration of
seizure but rather as seizure activity that does
not cease despite administration of two different
antiseizure medications.18 In such cases –
occurring in roughly 20% of patients with status
epilepticus – immediate continuous EEG
monitoring is indicated. If not already done,
intubation is needed, along with emergency
neurology consultation and transfer to ICU-level
care for closer monitoring.18-22 Sedative infusions
– such as propofol, pentobarbital, and
midazolam – is the mainstay of treatment for
RSE, making the ICU the most appropriate
setting for seizure activity monitoring and
maintenance of adequate ventilation and
hemodynamics.
COMPLICATIONS
For patients experiencing their first episode of
CSE, the mortality rate is roughly 16-20%, with
the most important prognostic factors being age
and underlying patient comorbidities.23-27 Other
complications include cardiac arrythmias and
cardiac injury (largely due to massive catecholamine release).28-30
Longer seizure duration is associated with worsening neurologic effects and decreased likelihood of reversibility. After approximately
30 minutes of seizure-like activity, neurologic effects notably worsen, with 10-50% of CSE patients left with long-term neurologic
complications31. Further, in patients without history of a seizure disorder, roughly 40% will later develop epilepsy – a four times
increased risk as compared to patients experiencing an acute, isolated symptomatic seizure.32-33
References
For a complete list of our citations, check out the website under this topic heading. We want to save an extra sheet of
paper since you are killing trees printing off discharge paperwork ;)
