A convulsion lasting more than 5 minutes (or repeated seizures without recovery) is status: start the algorithm. Always check glucose and treat hypoglycaemia. Protect the airway and give high-flow oxygen.
Timeline (APLS)
- Step 1 at 5 min: first benzodiazepine
- Step 2 at 10 min: second (and final) benzodiazepine, call for senior help
- Step 3 at around 10 min after the second dose: second-line agent
- Then rapid-sequence induction and PICU
Causes to consider
- Febrile convulsion, known epilepsy (missed medication)
- Hypoglycaemia, electrolytes, hyponatraemia
- CNS infection (meningitis, encephalitis), trauma or non-accidental injury
- Toxins and inborn errors of metabolism
0 to 5 min
- Secure airway, high-flow oxygen
- Check glucose, IV access
- Prepare a benzodiazepine
5 to 15 min (first line)
- IV lorazepam 0.1 mg/kg
- Buccal midazolam if no access
- Second dose at 10 min
Over 15 min (refractory)
- IV levetiracetam or phenytoin
- Call senior and anaesthetics
- RSI and PICU if ongoing
Treatment steps
1
1. ABCDE and glucose
Airway, high-flow oxygen, position, suction. Check capillary glucose and treat if low. IV or IO access and bloods.
Airway, high-flow oxygen, position, suction. Check capillary glucose and treat if low. IV or IO access and bloods.
↓
2
2. First benzodiazepine (5 min)
IV lorazepam 0.1 mg/kg, or buccal midazolam / rectal diazepam if no access.
IV lorazepam 0.1 mg/kg, or buccal midazolam / rectal diazepam if no access.
↓
3
3. Second benzodiazepine (10 min)
A single further dose of a benzodiazepine, then move to second-line. Do not give repeated benzodiazepines (respiratory depression).
A single further dose of a benzodiazepine, then move to second-line. Do not give repeated benzodiazepines (respiratory depression).
↓
4
4. Second line and beyond
IV levetiracetam or phenytoin (phenobarbital if on regular phenytoin). If still seizing, rapid-sequence induction, intubation and PICU.
IV levetiracetam or phenytoin (phenobarbital if on regular phenytoin). If still seizing, rapid-sequence induction, intubation and PICU.
Do not forget
- Treat hypoglycaemia (2 mL/kg of 10% glucose)
- Pyridoxine in infants with refractory seizures
- Consider CNS infection: antibiotics and aciclovir if suspected
Pitfalls
- Giving more than two doses of benzodiazepine
- Not checking glucose early
- Delaying second-line and the anaesthetist
- Missing a treatable cause
MedPrep - www.medprep.uk - Educational revision aid only. Not clinical guidance. Doses are adult examples; check the BNF, current guidelines and local policy, and seek senior advice. Nov 2026