How should a first seizure be managed in the emergency setting?

Emergency Management of First Seizure

For a first-time seizure in the emergency department, immediately assess airway, breathing, and circulation, place the patient in the recovery position to prevent injury, and activate EMS if the seizure lasts >5 minutes, occurs in water, involves trauma, or the patient doesn't return to baseline within 5-10 minutes post-ictally. 1

Immediate Seizure Management

During Active Seizure

• Protect the patient from injury by helping them to the ground, placing them on their side in the recovery position, and clearing the surrounding area 1
• Stay with the patient throughout the seizure episode 1
• Never restrain the patient or place anything in their mouth 1
• Do not administer food, liquids, or oral medications during the seizure or when the patient has decreased responsiveness 1

When to Activate Emergency Medical Services

Immediately activate EMS for: 1

• First-time seizure presentation
• Seizure duration >5 minutes (potential status epilepticus)
• Multiple seizures without return to baseline mental status between episodes
• Seizures occurring in water
• Associated traumatic injuries, difficulty breathing, or choking
• Seizure in infants <6 months of age
• Seizure in pregnant individuals
• Failure to return to baseline within 5-10 minutes after seizure cessation

Status Epilepticus Management (Seizure >5 Minutes)

First-Line Treatment: Benzodiazepines

Administer benzodiazepines as initial therapy for seizures lasting >5 minutes 2

Second-Line Treatment After Benzodiazepine Failure

Emergency physicians should administer an additional antiepileptic medication in patients with refractory status epilepticus who have failed optimal benzodiazepine dosing (Level A recommendation) 2

Preferred Second-Line Agents (Level B Evidence):

Administer IV phenytoin, fosphenytoin, or valproate as second-line therapy 2

Valproate (20-30 mg/kg at 40 mg/min): 2

• Equally effective as phenytoin (88% seizure cessation in both groups within 20 minutes)
• Advantage: Can be given more quickly with fewer adverse effects than phenytoin 2
• No hypotension risk (vs. 12% with phenytoin) 2
• Adverse effects: dizziness, thrombocytopenia, liver toxicity, hyperammonemia 2

Phenytoin (18-20 mg/kg IV at maximum 50 mg/min) or Fosphenytoin (18-20 PE/kg at maximum 150 PE/min): 2

• Traditional second-line agent with 56% success rate 2
• Phenytoin drawbacks: soft tissue injury with extravasation, hypotension, cardiac dysrhythmias, purple glove syndrome 2
• Fosphenytoin advantage: fewer adverse events than IV phenytoin, can be given IM 2

Alternative Second-Line Agents (Level C Evidence):

Consider IV levetiracetam, propofol, or barbiturates for refractory status epilepticus 2

Levetiracetam (30-50 mg/kg IV at 100 mg/min): 2

• Seizure cessation rates: 67-73% in various studies 2
• Major advantage: Safe with low incidence of hypotension and respiratory depression 2
• Minimal adverse effects (nausea, transient transaminitis) 2
• Evidence quality: primarily Class III studies 2

Propofol (2 mg/kg bolus; maintenance 5 mg/kg/h): 2

• Useful in intubated patients who continue seizing without hypotension 2
• Requires fewer mechanical ventilation days than pentobarbital (4 vs. 14 days) 2
• Less hypotension than barbiturates (42% vs. 77%) 2
• Adverse effects: injection site pain, heart failure, requires respiratory support 2

Phenobarbital (10-20 mg/kg; may repeat 5-10 mg/kg at 10 min): 2

• 58.2% effective in terminating seizures as initial medication 2
• Major limitation: Increased adverse effects including hypotension and respiratory depression 2

Diagnostic Evaluation for First Seizure

Essential Initial Assessment

Obtain detailed history from patient and witnesses, including smartphone videos when available 3

• Determine if the event was truly a seizure vs. syncope or psychogenic non-epileptic seizure 4, 5, 6
• Identify potential provoking causes: hypoglycemia, hyponatremia, hypoxia, drug toxicity, CNS infection, stroke, hemorrhage, withdrawal syndromes 2

Laboratory Studies

For adults with first-time seizure who have returned to normal baseline: 7

• Serum glucose and electrolytes (most common abnormalities associated with seizures) 6, 7
• Pregnancy test for women of reproductive age 7

For patients with comorbidities, focal neurologic examination, or abnormal mental status: 7

• Extensive diagnostic evaluation including additional laboratory studies 7

Neuroimaging

Neuroimaging is recommended for adults with first seizure 6

• MRI is preferred over CT except when acute intracranial bleeding is suspected 6
• Non-contrast head CT is indicated for patients with comorbidities, focal neurologic examination, or who have not returned to normal baseline 7

Electroencephalography (EEG)

EEG is recommended for patients presenting with first seizure 6

• ED EEG within 11 hours of seizure can identify 24% of patients appropriate for immediate antiepileptic drug initiation 8
• Substantial yield for epilepsy diagnosis when performed acutely in the ED 8

Disposition and Antiepileptic Drug Initiation

Patients NOT Requiring Hospitalization or Immediate Antiepileptic Drugs:

Patients with normal neurologic examination, normal laboratory results, and no structural brain disease do not require hospitalization or immediate antiepileptic medications 2, 6, 7

Antiepileptic Drug Considerations:

• Treatment with antiepileptic medications reduces 1-2 year seizure recurrence risk but does not reduce long-term recurrence or affect remission rates 6
• Initiation of antiepileptic therapy depends on assessed recurrence risk in conjunction with neurology consultation 7
• There is lack of evidence supporting one route of administration (oral vs. parenteral) over the other for preventing early recurrent seizures in known seizure disorder patients 2

Critical Pitfalls to Avoid:

• Do not prescribe benzodiazepines or antiseizure medications for functional seizures without co-occurring epilepsy 3
• Do not administer antipyretics (acetaminophen, ibuprofen) for febrile seizures—they are ineffective for stopping or preventing seizures 1
• Simultaneously search for and treat underlying causes while managing the seizure itself 2