Status epilepticus

Clinical Features

• Seizure > 20 minutes.
• Presume status in current seizure > 5 minutes

Differential Diagnosis

Seizure

• Epileptic seizure
  • First-time seizure
  • Seizure with known seizure disorder
  • Status epilepticus
  • Temporal lobe epilepsy
  • Non-compliance with anti-epileptic medications
  • Hyponatremia
  • INH toxicity
• Non-epileptic seizure
  • Meningitis
  • Encephalitis
  • Brain abscess
  • Intracranial hemorrhage
  • Alcohol withdrawal
  • Benzodiazepine withdrawal
  • Barbiturate withdrawal
  • Baclofen withdrawal
  • Metabolic abnormalities: hyponatremia, hypernatremia, hypocalcemia, hypomagnesemia, hypoglycemia, hyperglycemia, hepatic failure, uremia
  • Eclampsia
  • Neurocysticercosis
  • Posterior reversible encephalopathy syndrome
  • Impact seizure (head trauma)
  • Acute hydrocephalus
  • Arteriovenous malformation
  • Seizure with VP shunt
  • Toxic ingestion (amphetamines, anticholinergics, cocaine, INH, organophosphates, TCA, salicylates, lithium, phenothiazines, bupropion, camphor, clozapine, cyclosporine, fluoroquinolones, imipenem, lead, lidocaine, metronidazole, synthetic cannabinoids, theophylline, Starfruit)
  • Psychogenic nonepileptic seizure (pseudoseizure)
• Intracranial mass
• Syncope
• Hyperventilation syndrome
• Migraine headache
• Movement disorders
• Narcolepsy/cataplexy
• Post-hypoxic myoclonus (Status myoclonicus)

Diagnosis

• Clinical diagnosis

ED Management

Seizure Precautions

• Protect patient from injury
  • If possible, place patient in left lateral position to reduce risk of aspiration
  • Do not place bite block!
• Jaw thrust, a NPA and oxygen may be required
• An IV line should be placed

Medications

• Benzodiazepine (Initial treatment of choice)
  • Midazolam IM 10 mg (> 40 kg), 5mg (13-40 kg), or 0.2 mg/kg
    • May also be given IN at 0.2 mg/kg, max 10 mg
    • OR buccal at 0.3 mg/kg, max 10 mg
  • Lorazepam IV 4 mg or 0.1 mg/kg; may repeat one dose
  • Diazepam IV 0.15-0.2 mg/kg (up to 10 mg); may repeat one dose or PR 0.2-0.5 mg/kg (up to 20 mg) once
• Secondary medications
  • ESETT trial compared second line antiseizure medications and they all are equally efficacious. Therefore may be best to use the one with least side effects which is Levetiracetam
  • Levetiracetam IV 60 mg/kg, max 4500 mg/dose, or 1500 mg oral load (preferred in pregnancy)
  • Phenytoin IV 18 mg/kg at ≤ 50 mg/min (avoid in pregnancy)
  • Fosphenytoin IV 20-30 mg/kg at 150 mg/min (may also be given IM)
    • Contraindicated in pts w/ 2nd or 3rd degree AV block
    • Avoid phenytoin or fosphenytoin in suspected toxicology case due to sodium channel blockade
  • Valproic acid IV 20-40 mg/kg at 5 mg/kg/min, max 3000 mg (avoid in pregnancy)
• Refractory medications
  • Propofol 2-5mg/kg, then infusion of 2-10mg/kg/hr OR
  • Midazolam 0.2mg/kg, then infusion of 0.05-2mg/kg/hr OR
  • Ketamine loading dose 0.5 to 3 mg/kg, followed by infusion of 0.3 to 4 mg/kg/hr
  • Lacosamide IV 400 mg IV loading dose over 15 min, then maintenance dose of 200 mg q12hrs PO/IV
  • Phenobarbital IV 15-20 mg/kg at 50-75 mg/min
    • Then continuous infusion at 0.5-4.0 mg/kg/hr
    • Dose adjusted to suppression-burst pattern on continuous EEG
  • Consider consulting anesthesia for inhaled anesthetics (potent anticonvulsants)
• Others
  • Carbamazepine 8 mg/kg oral suspension, single oral load
  • Gabapentin 900 mg/day oral at 300 mg tid for 3 days
  • Lamotrigine 6.5 mg/kg single oral load

Other Considerations

• Secondary causes of seizure (e.g. hyponatremia, hypoglycemia, INH toxicity, ecclampsia)
• Nonconvulsive seizures or status epilepticus - get EEG
• Meds
  • First-Line
    • Lorazepam 2mg IV (up to 0.1mg/kg) OR diazepam 5-10mg IV (up to 0.15mg/kg); AND
    • Phenytoin 20-30mg/kg at 50mg/min OR fosphenytoin 20-30mg/kg/PE at 150mg/min
      • Phenytoin/fosphenytoin contraindicated in pts w/ 2nd or 3rd degree AV block
      • Phenytoin may cause hypotension due to propylene glycol diluent
      • Fosphenytoin may be given IM
  • Refractory
    • Valproic acid 20-40mg/kg at 5mg/kg/min OR
    • Phenobarbital 20mg/kg at 50-75mg/min (be prepared to intubate) OR
    • Propofol 2-5mg/kg, then infusion of 2-10mg/kg/hr OR
    • Midazolam 0.2mg/kg then inusion of 0.05-2mg/kg/hr OR
    • Ketamine 1.5mg/kg then 0.01-0.05mg/kg/hr
      • Contraindicated in pts w/ intracranial masses
• Consider secondary causes of seizure (e.g. hyponatremia, hypoglycemia, INH overdose, ecclampsia)
• Consider EEG to rule-out nonconvulsive status
• Consider prophylactic intubation
• Consider anesthesia c/s for inhaled anesthetics in OR for refractory status epilepticus

Neuro ICU Management

• Address immediate concerns ABCs
• Periodic blood gases q15min
• Seek primary etiology while treating
  • Treatment initiated in first 30 minutes has 80% response
  • Response at 2 hrs is down to 40%

Take a Stepwise Approach: Timeline

0-5 minutes

• Is this patient still seizing ? (look for return of consciousness) or if on EEG look to EEG (Reading EEGs link to come).
  • If this is first episode, may await seizure to break however ready materials to be given should seizure persist greater than 5 minutes
• Protect patient
  • turn on side prn for airway protection if vomitting to attenuate aspiration events. Remove any obvious dangerous material that may hurt the patient.
  • DO NOT, try to limit patient movement by holding extremities down. DO NOT place bite block (risk of occluding airway).
• Obtain Diagnostic labs (CBC, CEM 10, LFT, coagulation, AED levels (If indicated: assess if therapeutic), ECG, troponins, toxicology screen, pregnancy test (preparation for possible CT), blood gas, continuous SaO2, BP and continuous ECG.
• Ready medications to be given if seizure persists > 5 minutes
  • lorazepam (0.1mg/kg max given in 2-4 mg aliquots )
  • AED loading agent (Fosphenytoin 20 PE/kg, at 150 mg/min)
    • PE = phenytoin equivalents (1.5 mg fosphenytoin = 1 mg phenytoin)
    • 20 mg/kg phenytoin is given slower at 50 mg/min
  • Thiamine 100mg IV along with 50ml D50IV
  • Consider 5 g of pyridoxine (Vitamin B6) over 5-10 min, repeat up to total 20 g, for TB patients with suspected INH toxicity (urban hospital, especially in international medicine)
• Briefly familiarize patient H+P to help guide diagnostic causes
  • PMHx: Sz History? (get AED levels/home dosages), CNS insults?
    • description of previous seizures semiology (if applicable) – jerking/automatisms/gaze deviation
  • Medications: anything that reduces seizure threshold?
  • Physical Exam: Neuro evaluation
    • while in convulsive status patient is obviously seizing and one should continue timeline for acute treatment. The neuro exam is primarily focused on identifying 1. Neuro signs to help localize seizure focus 2.identifying NCSE; focusing on recognizing an improvement of wakefulness/mental status.
      • No improvement in wakefulness >20 minutes or continued AMS > 30-60 minutes prompts concern for NCSE and requires 24-48hr cEEG

6-10 minutes (seizure persists)

• Administer thiamine 100mg IV along with 50ml D50IV (empirically for possible hypoglycemia)
  • May forego if hypoglycemia ruled out with recent CEM panel.
• Administer the 2-4mg lorazepam aliquot over 2 minutes.
  • Repeat 1x (max dose 0.1mg/kg) if seizure continues another 5 minutes.
  • If no IV access available. Diazepam may be given rectally (20mg PR) or Midazolam (10mg intrabucally/intranasally).

10-20 minutes

• Admin AED loading agent (Fosphenytoin 20 PE/kg). MAX INFUSION RATE 150mg/min
  • Phenytoin associated with hypotension. Fosphenytoin use attenuates some of this risk however still significant. Administer with frequent BP checks and ECG monitoring.
    • Continue AED maintenance with target phenytoin level 2-3 G/mL after seizure subsides (typically qd checks). Defer to neurology for long term AED management.
  • If seizure persists may rebolus 1x with additional Fosphenyoitn 10 PE/kg bolus.
• OTHER OPTION
  • if patient on AED at home, may reload with home medication: Some examples below
    • IV valproate: 20mg/kg over 10 minutes. May re bolus (same dose) 1x if seizure persists > 5 minutes following
    • IV keppra 1000-4000mg IV
• Reassess ABC status
• Make arrangements for possible ICU transfer ( If applicable - as next step is intubation).

20-60 minutes (refractory status epilepticus)

• Intubate for airway protection (As we will definitively sedate to the point of respiratory compromise)
• Place arterial line (Continuous BP monitoring with propofol infusion)
• Medications (May use propofol as pressure tolerates, otherwise midazolam; Typically start with propofol since may regain neuro exam faster, and add midazolam).
  • IV propofol (causes hypotension)
    • 1mg/kg bolus with continued boluses (same dose) every 3-5 minutes until seizures stop (As BP tolerates).
    • May place on cIV infusion 1-15 mg/kg/h (Do not exceed >5mg/kg/h in 24 hrs)
  • IV midazolam (less hypotension, longer sedation than propofol)
    • 0.2mg/kg bolus with repeat boluses (Same dose) every 5 minutes until seizures stop (max dose 2mg/kg)
    • May place on cIV 0.05-2.0 mg/kg/h (up to 200mg/h for 70kg patient).

> 60 minutes

• Place in pentobarbital coma
  • 5 mg/kg up to 50mg/min. Repeat boluses (same dose) until seizure stop.
  • cIV 1mg/kg/h titrated to suppression on cEEG.

Disposition

• Admit

External Links

EM Nerd Adventure of dancing men

See Also

• Seizure