Status epilepticus
Background
- Continuous seizure activity lasting >5 minutes, or ≥2 seizures without return to baseline[1]
- Time-sensitive emergency — mortality increases with duration of seizure
- 30-day mortality: 20% overall; higher in elderly and those with anoxic injury
- Refractory SE: seizures persisting despite two appropriate first-line agents
- Super-refractory SE: seizures persisting >24 hours despite anesthetic agents
Etiology
- Anti-epileptic drug (AED) non-compliance or subtherapeutic levels (most common in known epileptics)
- Acute CNS injury: stroke, TBI, CNS infection, tumor
- Metabolic: hypoglycemia, hyponatremia, hypocalcemia, hepatic failure, uremia
- Toxicologic: alcohol withdrawal, Benzodiazepine withdrawal, INH, organophosphates, cocaine, TCA
- Eclampsia (pregnant/postpartum patients)
- Febrile status epilepticus in children
Clinical Features
- Generalized convulsive SE: continuous tonic-clonic activity, most readily recognized
- Non-convulsive SE: subtle or no motor manifestations; persistent altered mental status
- Must maintain high suspicion in patients who remain altered after apparent seizure cessation
- Complications: rhabdomyolysis, hyperthermia, lactic acidosis, aspiration, neuronal injury
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)
Evaluation
- Bedside glucose — immediately
- Labs: BMP (Na, Ca, Mg, glucose), CBC, AED levels, lactate, VBG, LFTs, toxicology screen
- CT head — once stabilized; evaluate for structural cause
- Continuous EEG — if available; essential to diagnose non-convulsive SE
- LP if infection suspected (after CT and when safe)
- CK, urinalysis (myoglobinuria) if prolonged seizure
Management
Time 0-5 min: Stabilize
- ABCs, supplemental O2, cardiac monitor, IV access
- Glucose: check immediately; give D50W 50 mL IV (or D10W) if hypoglycemic
- Thiamine 100 mg IV before glucose if malnourished or alcoholic
- Position patient to prevent aspiration; suction as needed
Time 5-20 min: First-Line — Benzodiazepines
- Lorazepam 0.1 mg/kg IV (max 4 mg/dose), may repeat x1 in 5 min[2]
- If no IV access: Midazolam 10 mg IM (most effective prehospital per RAMPART trial)
- Alternatives: Diazepam 0.2 mg/kg IV (max 10 mg), or diazepam 20 mg PR
Time 20-40 min: Second-Line — Anti-Epileptic Drug
- Levetiracetam 60 mg/kg IV (max 4500 mg) over 15 min[3]
- Fosphenytoin 20 mg PE/kg IV (max rate 150 mg PE/min)
- Valproic acid 40 mg/kg IV (max 3000 mg) over 10 min
- ESETT trial: all three equally effective (~50% success each)
Time >40 min: Refractory SE
- Intubation and continuous infusion of anesthetic agent:
- Midazolam 0.2 mg/kg IV bolus, then 0.1-2 mg/kg/hr
- Propofol 2 mg/kg IV bolus, then 2-10 mg/kg/hr (monitor for propofol infusion syndrome)
- Pentobarbital 5 mg/kg IV bolus, then 1-5 mg/kg/hr
- Continuous EEG monitoring required
- Target: burst-suppression for 24-48 hours
Special Situations
- INH overdose: Pyridoxine (B6) gram-for-gram (empiric 5 g IV if dose unknown)
- Eclampsia: Magnesium sulfate 4-6 g IV
- Hyponatremia: Hypertonic saline (3%) 100 mL IV bolus
Disposition
- ICU admission for all SE patients
- Neurology consultation
- Patients with rapidly terminated seizures who return to baseline may be managed on a monitored floor
See Also
References
- ↑ Trinka E, et al. A definition and classification of status epilepticus. Report of the ILAE Task Force. Epilepsia. 2015;56(10):1515-1523. PMID 26336950.
- ↑ Silbergleit R, et al. Intramuscular versus intravenous therapy for prehospital status epilepticus. N Engl J Med. 2012;366(7):591-600. PMID 22335736.
- ↑ Kapur J, et al. Randomized Trial of Three Anticonvulsant Medications for Status Epilepticus (ESETT). N Engl J Med. 2019;381(22):2103-2113. PMID 31774955.