Status epilepticus

Metabolic	Primary central nervous system	Toxidromes/toxins
• Hypoxia • Hypoglycemia • Hyponatremia • Hypocalcemia • Hypomagnesemia • Inborn errors of metabolism	• Trauma • Infections • Cerebral vascular accident • Hemorrhage • Vasculitis • Seizure disorder with other medical condition • Seizure disorder medication abstinence • Seizure disorder with recent medication change • Pre- or postpartum eclampsia • Tumors	• Anticholinergic • Sympathomimetic • Ethanol withdrawal • Serotonin syndrome • Tricyclic antidepressant • Salicylate • Isoniazid • Tramadol • Bupropion • Venlafaxine • Strychnine

Presentation

Classic presentation

Unresponsive with rhythmic movement of one or more body parts, or tonic eye deviation; of note, myotonic movements and incontinence may be seen in syncope as well as seizure.
Less commonly, patients with altered mental status may actually be in NCSE.
There is an association with seizures and posterior shoulder dislocations.
Seizures are followed by a postictal state – defined as an altered mental status of variable duration.
A postictal state may include a Todd’s paralysis in which focal neurological deficits may mimic a stroke.

Critical presentation

Seizures, which may be the result of CNS infection, require early and empiric antibiotics, antivirals, and possibly steroids, ideally before lumbar puncture is performed. Do not delay administration of these medications while awaiting lumbar puncture.
Seizures may require additional treatment and can be refractory to first-line agents (i.e., benzodiazepines) and second-line agents (i.e., phenytoin, phenobarbital, and valproate).
Be aware that patients could be seizing with little or no muscle twitching or because of concomitant administration of neuromuscular blockade medications.

Diagnosis and evaluation

Immediate bedside tests
- Bedside glucose level to rapidly evaluate for hypoglycemia.
- Electrocardiogram to screen for hyperkalemia or toxidrome.
Laboratory tests
- Obtain basic serum electrolytes, calcium, magnesium, phosphorus, and glucose.
- Lactate will be very elevated if blood is drawn during or immediately after tonic-clonic activity. Recheck the lactate level after seizures have successfully been aborted.
- Get total creatine phosphokinase (CK/CPK) to assess for associated rhabdomyolysis.
- Consider drug levels such as antiepileptic drug levels, ethanol, salicylate, acetaminophen, and tricyclic level.
- Urine toxicology test to screen for cocaine or other ingestions.
- Urine/serum pregnancy test to screen for pregnancy.
Imaging studies
- Consider noncontrast head CT to evaluate for structural cause for the seizure such as hemorrhage, or mass, particularly for first-time seizures.
Further testing
- Consider lumbar puncture and empiric administration of antibiotics/antiviral medications if an infectious etiology is suspected.
- Consider STAT bedside EEG if concerned about NCSE.

Critical management

Assess airway security. Patients unable to protect the airway may require rapid sequence intubation (RSI).
Rapidly identify and correct hypoglycemia and hypoxia with dextrose and high-flow oxygen.
Administer benzodiazepines as first-line therapy:
- Typically lorazepam IV/IM (0.1 mg/kg every 5–10 minutes), diazepam IV/PR (0.2 mg/kg every 5 minutes), or midazolam IV/IM (0.2 mg/kg every 5 minutes).
- Do not give diazepam IM because it is erratically absorbed.
Administer second-line agents if necessary:
- Phenytoin (20 mg/kg at 50 mg/minute) or fosphenytoin (20 mg/kg at 150 mg/minute).
- If still seizing then consider
  - Propofol
  - Phenobarbital
  - Pentobarbital.
If seizures are refractory to first- and second-line agents, consider levetiracetam or lacosamide, or induction with general anesthesia by inhalational anesthetics.
Treat the underlying cause
- Infectious: Early administration of antibiotics, antivirals, and steroids before lumbar puncture if infectious etiology is suspected.
- Hyponatremia: If seizures are from hyponatremia, administer hypertonic saline (3% NS) 1–2 mL/kg over 10 minutes until seizures stop. Then recheck sodium level hourly and correct by 1 mEq/L per hour to prevent osmotic demyelination syndrome.
- Eclampsia: If seizures are from eclampsia or hypomagnesemia, administer magnesium (4–6 g over 15–20 minutes then 2 g/hour).
- Toxic ingestion: Consider antidotes if isoniazid, tricyclic antidepressant, salicylate, or organophosphate overdose is suspected – contact local poison control center or toxicology consultants.
Monitor and treat expectantly for hyperthermia, rhabdomyolysis, hyperkalemia, and acute kidney injury.
Patients with status epilepticus should be admitted to an intensive care unit (ICU) setting.

Sudden deterioration

The most likely causes for sudden decompensation are airway compromise/respiratory failure, sepsis/septic shock, and recurrent seizure activity.
Patients requiring multiple boluses of medications or continuous infusions should be considered for intubation for airway protection.
Patients with an infectious etiology may rapidly progress to sepsis and require additional hemodynamic support.
Prolonged seizure activity with or without overt muscle twitching is associated with increased mortality.

Vasopressor of choice (if necessary): norepinephrine, but may depend on underlying etiology.