Status Epilepticus
Summary
Status Epilepticus is a neurological emergency defined as a seizure lasting >5 minutes OR two or more seizures without recovery of consciousness in between. Historically defined as >30 minutes, the operational definition was lowered to 5 minutes because most self-terminating seizures stop within 2-3 minutes, and pharmacoresistance increases with duration. Management requires a rapid, stepped approach: Benzodiazepines -> Anti-Epileptic Drugs (AEDs) -> Anaesthesia. [1,2]
Clinical Pearls
Refractory Status: The phenomenon where GABA receptors (which Benzodiazepines target) become internalised into the cell during prolonged seizures. This makes the patient resistant to Benzos. Hence, do NOT keep giving doses of Benzos indefinitely. If 2 doses fail, move to second-line agents immediately.
Glucose, Glucose, Glucose: Never forget to check capillary glucose. Hypoglycaemia is an instantly reversible cause of status. Giving IV Thiamine before Glucose in alcoholics prevents Wernicke's Encephalopathy.
Phenytoin Kinetics: Phenytoin has zero-order kinetics (non-linear). Small dose increments can lead to toxicity (Arrhythmias/Hypotension). It requires cardiac monitoring during loading.
Incidence
- Bimodal: Peaks in children (less than 1 year) and the elderly (>60 years).
- Mortality: 20% (higher in elderly and anoxia).
Common Causes
- Low AED levels: Non-adherence or drug interactions. (Most common in known epileptics).
- Cerebrovascular: Old stroke scar or new Stroke/Haemorrhage.
- Metabolic: Hypoglycaemia, Hyponatraemia, Hypocalcaemia, Uraemia.
- Toxins/Withdrawal: Alcohol withdrawal, Trycyclic overdose.
- Infection: Meningitis, Encephalitis.
Mechanism
- Failure of Inhibition: Exhaustion of GABA-ergic inhibitory reserves.
- Excess Excitation: Excessive Glutamate acting on NMDA receptors causes massive calcium influx.
- Excitotoxicity: Calcium influx leads to cell death (apoptosis/necrosis).
- Systemic Effects: Hypoxia, Acidosis, Rhabdomyolysis (from muscle contraction), Hyperthermia.
| Condition | Features |
|---|---|
| Status Epilepticus | Rythmic jerking, Unconscious, Cyanosis. |
| PNES (Non-Epileptic) | Asynchronous thrashing, Pelvic thrusting, Eyes closed, Resistance to eye opening. |
| Decerebrate Posturing | Brainstem coning (Tonic extension). |
Generalised Convulsive Status Epilepticus (GCSE)
Non-Convulsive Status Epilepticus (NCSE)
Immediate
- Bedside Glucose: Rule out Hypoglycaemia.
- Blood Gas (ABG/VBG): Check pH (Acidosis common), Sodium, Lactate (Usually elevated post-seizure).
- Bloods: FBC, U&E, LFT, CRP, Calcium, Magnesium, AED Levels.
Post-Stabilisation
- CT Head: Rule out Bleed/Mass/Acute Stroke.
- Lumbar Puncture: If sepsis/meningitis suspected (after CT).
Management Algorithm (Advanced Life Support)
SEIZURE > 5 MINUTES
↓
STEP 1: RESUSCITATION (0-5 mins)
• Secure Airway (High Flow O2)
• Check Glucose (Give IV Dextrose if Low)
• IV Access x 2
↓
STEP 2: BENZODIAZEPINES (5-10 mins)
• **Lorazepam** 4mg IV
OR Buccal Midazolam 10mg (if no IV)
OR Rectal Diazepam 10mg
• Repeat ONCE after 5 mins if no response
↓
STEP 3: AED LOADING (10-30 mins)
(Start immediately if Benzos fail)
• **Levetiracetam** 60mg/kg IV (Max 4.5g)
OR
• **Phenytoin** 20mg/kg IV (Max 2g) - Monitor ECG!
OR
• **Valproate** 40mg/kg IV (Max 3g)
↓
STEP 4: ANAESTHESIA (>30 mins)
• Rapid Sequence Induction (RSI) - Intubate
• **Propofol** / **Thiopental** Infusion
• Transfer to ICU
• EEG Monitoring
1. Benzodiazepines
- Lorazepam: Preferred IV agent (remains in vascular compartment longer than Diazepam).
- Midazolam: Preferred Community/Pre-hospital agent (Buccal/IM).
2. Second Line AEDs (The ESETT Trial 2019)
- Levetiracetam: Now often preferred due to safety profile (no cardiac monitoring needed, fast infusion).
- Phenytoin: Risk of arrhythmias (Purple Glove Syndrome if extravasates). Must infuse slowly (less than 50mg/min).
- Valproate: Avoid in women of childbearing potential (Teratogenic), but in life-threatening status, this is secondary.
3. Refractory Status
- Need to suppress brain activity ("Burst Suppression" on EEG).
- Drugs: Propofol, Thiopental, Midazolam infusions.
- Ketamine: Sometimes used as 4th line (NMDA antagonist).
- Respiratory: Hypoxia, Aspiration Pneumonia, Neurogenic Pulmonary Oedema.
- Cardiovascular: Arrhythmias, Hypotension/Hypertension.
- Metabolic: Rhabdomyolysis -> AKI (Myoglobinuria).
- Neurological: Permanent brain injury (Mesial Temporal Sclerosis).
- Mortality: 20% overall at 30 days.
- Morbidity: Cognitive decline, new focal neurological deficits. (Depends on duration - "Time is Brain").
Key Guidelines
| Guideline | Organisation | Key Recommendations |
|---|---|---|
| Status Epilepticus | NICE (2021) | Buccal Midazolam for community. Lorazepam IV first line hospital. |
| ESETT Trial | NEJM (2019) | Levetiracetam, Fosphenytoin, Valproate are equally effective as 2nd line. |
Landmark Evidence
1. ESETT (Established Status Epilepticus Treatment Trial) 2019
- Multicentre RCT comparing Levetiracetam, Fosphenytoin, and Valproate for benzo-refractory status.
- Result: No significant difference in efficacy (~45-47% seizure cessation). Levetiracetam often chosen for ease of use.
2. RAMPART (Rapid Anticonvulsant Medication Prior to Arrival Trial)
- IM Midazolam was superior to IV Lorazepam in pre-hospital setting (due to speed of administration - no IV line needed).
What is Status Epilepticus?
It is a dangerous state where a seizure (fit) does not stop by itself. Usually, a seizure stops within 2 minutes. If it lasts longer than 5 minutes, it is unlikely to stop on its own and needs emergency medicine.
What do doctors do?
We use "rescue medication" first (sedatives like Benzodiazepines) to calm the brain. If that doesn't work, we use strong anti-epilepsy drugs through a drip. In very severe cases, we put the patient to sleep (induced coma) in ICU to let the brain rest.
Is it dangerous?
Yes. Prolonged seizing can starve the brain of oxygen and cause damage. It also strains the heart and lungs. That is why we treat it so aggressively.
What should I do if I see someone fitting?
- Safe: Move dangerous objects away.
- Time: Check your watch.
- Ambulate: If it lasts >5 minutes, call an Ambulance.
- Side: Put them in the recovery position once it stops. Do NOT put anything in their mouth.
Primary Sources
- Kapur J, et al. Randomized Trial of Three Anticonvulsant Medications for Status Epilepticus (ESETT). N Engl J Med. 2019.
- NICE. Epilepsies in children, young people and adults (NG217). 2022.
- Silbergleit R, et al. Intramuscular versus intravenous therapy for prehospital status epilepticus (RAMPART). N Engl J Med. 2012.
Common Exam Questions
- Pharmacology: "Dose of IV Lorazepam?"
- Answer: 4mg.
- Protocol: "Benzos failed, what next?"
- Answer: IV Levetiracetam / Phenytoin.
- Paediatrics: "Child fitting >5 mins, no IV access?"
- Answer: Buccal Midazolam or Rectal Diazepam.
- Toxicology: "Seizures + Alcohol history?"
- Answer: Withdrawal fits (Delirium Tremens) - Treat with Benzos (Chlordiazepoxide/Lorazepam). Don't forget Thiamine.
Viva Points
- Why Thiopental?: It is an old barbiturate anaesthetic. It is very effective at stopping brain activity but has a very long half-life (accumulates in fat). The patient may take days to wake up after infusion stops. Propofol clears much faster.
- Pseudostatus: Psychogenic Non-Epileptic Seizures usually involve eyes CLOSED, whereas true seizures eyes are usually OPEN.
Medical Disclaimer: MedVellum content is for educational purposes and clinical reference. Clinical decisions should account for individual patient circumstances. Always consult appropriate specialists.