Status Epilepticus in Children

Background

• Status epilepticus (SE) is a condition characterized by a prolonged period of either continuous seizure activity or recurrent seizure activity without a return to baseline. The condition results either from failure of mechanisms responsible for seizure termination or from initiation of mechanisms, which lead to abnormally prolonged seizures.
• Seizure duration criteria vary.
  • International League Against Epilepsy (ILAE) criteria varies by seizure type - ≥ 5 minutes for tonic clonic seizures, ≥ 10 minutes for focal seizures without impaired consciousness, ≥ 10-15 minutes for absence seizures.
  • Neurocritical Care Society (NCS) criteria is ≥ 5 minutes of either continuous clinical or electrographic seizure activity, or recurrent seizure activity without return to baseline between seizures.
• SE may occur with prominent motor symptoms (often referred to as convulsive SE) or without prominent motor symptoms (often referred to as nonconvulsive SE), and may be further subtyped based on various classification systems.
• Prolonged seizures can have long-term consequences, including neuronal death, neuronal injury, and alteration of neuronal networks, depending on the seizure type and its duration.
• Evaluation is directed toward determining the underlying etiology of SE, which is wide-ranging. Common causes in children include febrile seizure, central nervous system infection, inborn error of metabolism, and ingestion.

Evaluation

• Diagnose status epilepticus in children with prolonged clinical or electrographic seizure.
• Diagnostic workup should be completed as soon as possible and occur simultaneously and in parallel with treatment.
• Immediate testing should include:
  • fingerstick glucose
  • vital signs (including oxygen saturation)
  • blood tests, including glucose, complete blood count, basic metabolic panel, calcium, magnesium
• Consider additional testing based on clinical presentation, including:
  • electroencephalogram (Weak recommendation)
  • neuroimaging (Weak recommendation)
  • lumbar puncture (Weak recommendation)
  • toxicology screen (urine and blood) (Weak recommendation)
  • other blood or urine tests (such as, antiseizure medication levels or tests for inborn errors of metabolism) (Weak recommendation)

Management

• Stabilization and monitoring should be started immediately and continued in parallel with pharmacologic treatment, including:
  • assessing and supporting airway, breathing, circulation
  • performing neurologic examination
  • obtaining IV access and diagnostic tests
• The goal of pharmacologic treatment is rapid cessation of seizure activity.
  • Give benzodiazepines as the first-line treatment for status epilepticus (SE) (Strong recommendation).
    • Preferred options include:
      • lorazepam (Strong recommendation) 0.1 mg/kg IV, may repeat dose once
      • midazolam (Strong recommendation) 5 mg intramuscularly if 13-40 kg, 10 mg intramuscularly if > 40 kg, or 0.2 mg/kg intramuscularly
      • diazepam (Strong recommendation) 0.15-0.2 mg/kg IV, may repeat dose once
    • If IV or intramuscular formulations are not feasible or available, consider:
      • buccal or intranasal midazolam (Strong recommendation) 0.5 mg/kg buccally, 0.2 mg/kg intranasally
      • rectal diazepam (Strong recommendation) 0.2-0.5 mg/kg per rectum
  • Second-line options for benzodiazepine-refractory SE include the following (ranges indicate between-guideline differences in recommended dosing):
    • valproic acid (Strong recommendation) 20-40 mg/kg IV
    • fosphenytoin (Weak recommendation) 20 mg/kg phenytoin equivalent IV
    • levetiracetam (Weak recommendation) 20-60 mg/kg IV
    • phenobarbital (Weak recommendation) 15-20 mg/kg IV
    • phenytoin (Weak recommendation) 20 mg/kg IV
    • midazolam continuous infusion (Weak recommendation) 0.2 mg/kg IV at 2 mg/minute loading dose, then continuous infusion at 0.05-2 mg/kg/hour
  • Options for SE refractory to first- and second-line antiseizure medications include:
    • repeated second-line therapies (Weak recommendation)
    • anesthetic doses of midazolam, propofol, pentobarbital, or thiopental (Weak recommendation)
    • lacosamide (Weak recommendation)
    • topiramate (Weak recommendation)
  • Suggested timelines vary, but benzodiazepines are generally given during the first 20 minutes after seizure onset, with second-line drugs administered from 5 to 40 minutes after onset, and third-line drugs given if seizure activity persists ≥ 30-40 minutes from onset.
• In children with SE refractory to pharmacologic treatments, options that may be considered include:
  • ketogenic diet
  • therapeutic hypothermia
  • immunomodulation
  • neurosurgery
  • vagal stimulation
  • electroconvulsive therapy