Chapter 42: Status Epilepticus

DEFINITION

Status epilepticus (SE) is defined as 5 minutes or more of (1) continuous clinical and/or electrographic seizure activity or (2) recurrent seizure activity without recovery (returning to baseline) between seizures.¹

• May be convulsive (with motor features) or nonconvulsive (electrographic seizures only)

• SE progresses in phases

  • Early SE (5–30 minutes), established SE (>30 minutes), and refractory SE

  • Refractory status epilepticus

    • Clinical or electrographic seizures that persist after an adequate dose of an initial benzodiazepine and a second appropriate antiseizure medication

    • Associated with poor outcome, with mortality up to 30%, related to young age, etiology, and multifocal or generalized EEG abnormalities

BACKGROUND AND EPIDEMIOLOGY

• Epidemiology and morbidity of SE

  • Incidence of first-time SE is approximately 18 to 23 per 100,000 children per year²

  • Fifty percent of children with new-onset convulsive SE are neurologically healthy

  • One-year recurrence risk is 16% with 3% mortality, which is lower than adults

  • Risk for mortality and long-term morbidity related to primary cause of the seizure

• Factors associated with increased morbidity in SE

  • Time to the first dose of benzodiazepine in children with SE is often delayed or the drug not given until arrival at a hospital³

  • Delay in administration of the first anticonvulsant is associated with longer SE duration⁴

CAUSES OF SE

Prolonged febrile seizures and seizure due to remote neurologic injury account for 50% of SE cases in children.

• Other common causes in order of frequency include

  • Acute new neurologic injury

    • Central nervous system (CNS) infection; cardiac arrest, stroke; traumatic brain injury; drug or toxin

  • Acute exacerbation of underlying epilepsy

    • Missed anticonvulsant or subtherapeutic levels

    • Intercurrent illness

  • Progressive neurologic disorder

KEY PRINCIPLES OF SE MANAGEMENT

• After 5 to 10 minutes, most seizures will not stop unless treated with an anticonvulsant

• Early, sequential administration of adequate doses of anticonvulsants is essential⁵

• Treatment should be given in the field prior to arrival in the ICU

• Identify and treat precipitating cause

• Manage systemic complications

• All units should have a management pathway and agreed on time frame for treatment⁶

TREATMENT

Incipient SE 0 to 5 minutes of seizure onset

• Stabilize airway, breathing, and circulation

• Obtain fingerstick glucose in first-line labs

• Obtain IV access and administer IV benzodiazepine if seizure lasts 5 minutes

  • If IV access is not possible, administer benzodiazepine via intramuscular, intranasal, rectal, or buccal route (see Table 42-1)

  • Do not delay treatment in order to obtain IV access

Early (5–30 min) and established (>30 min) SE (Figure 42-1)