Status Epilepticus

Status Epilepticus Summary

Definition

Seizures lasting ≥5 minutes
Medical emergency requiring immediate treatment
Risk increases with duration

Resuscitation

Position to avoid injury
Secure airway, support respiration
Provide oxygen
Establish IV access
Check and correct hypoglycemia

Medication Timeline

0-5 min: 1st benzodiazepine
5-10 min: 2nd benzodiazepine
10-20 min: 2nd line AED
20-40 min: 3rd line options

Medications

1st line: Benzodiazepines
2nd line: Levetiracetam, Phenytoin, Valproate
3rd line: Phenobarbital, General anesthesia

Investigations

Blood gases, glucose, electrolytes
Renal/liver function, FBC, clotting
AED levels, toxicology screen
ECG, CXR, EEG, neuroimaging

Monitoring

Neurological observations
Vital signs monitoring
EEG for refractory cases
ICU level care required

Overview

Status epilepticus is defined as continuous seizure activity lasting 5 minutes or more, or recurrent seizures without recovery of consciousness between episodes. It is a neurological emergency that requires immediate intervention to prevent complications and potential neurological damage.

Medical Emergency

Provide resuscitation and immediate emergency treatment for children, young people and adults who have convulsive status epilepticus.

Resuscitation and General Measures

Initial Management

Position the patient to avoid injury
Secure the airway
Support respiration including provision of oxygen
Assess cardiorespiratory function

Medical Interventions

Establish intravenous access
Check blood glucose and correct hypoglycemia
Institute regular monitoring
Administer emergency antiepileptic drug therapy

Special Considerations

Administer glucose and/or intravenous thiamine (Pabrinex) if alcohol abuse or impaired nutrition suspected
Treat severe acidosis (discuss with critical care)
Maintain blood pressure (pressor therapy if needed)

Treating Underlying Causes

Consider and treat potential underlying causes of status epilepticus:

Medication related: Poor compliance, poor absorption, recent AED changes, medication interactions, or subtherapeutic levels
Infection: CNS or systemic infections
Electrolyte disturbance: Hyponatremia, hypocalcemia, hypomagnesemia
Toxicity or drug withdrawal: Including alcohol withdrawal
CNS pathology: Tumor, stroke, encephalitis, PRES (Posterior Reversible Encephalopathy Syndrome), neurodegenerative diseases

Emergency Antiepileptic Drug Therapy

Initial Management (0-5 minutes)

If individualised emergency management plan available: follow plan
If no plan available:
- Benzodiazepine (buccal midazolam or rectal diazepam) in community
- IV lorazepam if IV access and resuscitation facilities available

If No Response to First Dose (5-10 minutes)

Continue following individualised emergency management plan if available
Give second dose of benzodiazepine if seizure continues

If No Response to 2 Doses of Benzodiazepine (10-20 minutes)

Administer second-line treatment intravenously:
- Levetiracetam (off-label use, but quicker to administer with fewer adverse effects)
- Phenytoin
- Sodium valproate

If No Response to Second-Line Treatment (20-40 minutes)

Consider trying an alternative second-line treatment under expert guidance
If still no response, consider third-line options under expert guidance:
- Phenobarbital
- General anesthesia

Emergency Investigations

Essential Blood Tests

Blood gases (arterial or venous)
Glucose level
Renal and liver function tests
Calcium and magnesium levels
Full blood count (including platelets)
Blood clotting studies
Antiepileptic drug levels
Save 5 ml of serum and 50 ml of urine for future analysis (toxicology, especially if cause uncertain)

Other Investigations

Immediate Tests

12-lead ECG
Chest radiograph (to evaluate for aspiration)

Additional Investigations

Brain imaging (CT or MRI)
Lumbar puncture (if infection suspected)
EEG monitoring

Based on Clinical Suspicion

Toxicology screen
Metabolic workup
Autoimmune encephalitis panel

Monitoring and Ongoing Management

Essential Monitoring

Regular neurological observations
Continuous measurement of pulse, blood pressure, temperature
ECG monitoring
Regular biochemistry, blood gases, clotting studies
Blood count and drug level monitoring

Level of Care Required

Patients require full ICU facilities
Care should be shared between anaesthetist and neurologist
EEG monitoring is necessary for refractory status epilepticus
Consider possibility of non-epileptic status

EEG Monitoring Goals in Refractory Status

Primary end-point: Suppression of epileptic activity on EEG
Secondary end-point: Burst-suppression pattern (short intervals of up to 1 second between bursts of background rhythm)

Special Considerations

Refractory Status Epilepticus

Defined as status epilepticus that continues despite adequate doses of first-line and second-line antiepileptic drugs.

Requires ICU admission for continuous EEG monitoring
May require continuous infusion of midazolam, propofol, or barbiturates
Goal is burst suppression pattern on EEG
Consider alternative diagnoses if not responding to treatment

Super-Refractory Status Epilepticus

Status epilepticus that continues or recurs 24 hours or more after anesthesia has been started.

May require additional treatments: ketamine, immunomodulatory therapy, ketogenic diet, hypothermia, or surgical options
High mortality and morbidity rates
Requires multidisciplinary approach with neurology, critical care, and often epilepsy surgery team

Non-Convulsive Status Epilepticus

Characterized by altered mental status or behavior changes without overt convulsions.

Diagnosis requires EEG confirmation
Can be easily missed without a high index of suspicion
Treatment follows similar principles to convulsive status

Complications and Prognosis

Acute Complications

Respiratory failure and aspiration pneumonia
Cardiac arrhythmias and hemodynamic instability
Hyperthermia
Rhabdomyolysis and renal failure
Cerebral edema and increased intracranial pressure

Long-Term Complications

Hippocampal injury and memory impairment
Cognitive deficits
Increased risk of future epilepsy
Motor deficits
Psychiatric sequelae

Prognostic Factors

Duration of status epilepticus
Etiology (worse with acute symptomatic causes)
Age (worse in elderly and very young)
Level of consciousness at presentation
EEG patterns

Mortality Rates

Overall mortality ranges from 7-39%, with higher rates in elderly patients and those with acute symptomatic causes. Refractory status epilepticus has mortality rates of 16-39%.