Status Epilepticus in Children
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Direct answer
Status epilepticus is now defined operationally as a seizure lasting five minutes or more, or repeated seizures without recovery of consciousness — the five-minute clock replaced the old thirty-minute definition because benzodiazepine efficacy falls with delay. The staged algorithm runs: zero to five minutes, airway-breathing-circulation, check glucose, and a benzodiazepine — intravenous lorazepam 0.1 mg/kg (maximum 4 mg) or intramuscular or intranasal midazolam 0.2 mg/kg; five to twenty minutes, a second benzodiazepine dose then a second-line agent — fosphenytoin 20 mg/kg equivalents, levetiracetam 40-60 mg/kg, or valproate 40 mg/kg; beyond that, refractory status warrants anaesthetic infusion with intubation and electroencephalography. In a refractory infant, pyridoxine 100 mg intravenously is the diagnostic-therapeutic move; phenobarbitone 20 mg/kg remains first-line in neonates.
What you must remember
- Definition: seizure of five minutes or more, or serial seizures without regaining consciousness; the older 30-minute definition is historical, and the question is deliberately set on the difference.
- First-line doses: lorazepam 0.1 mg/kg IV (max 4 mg), midazolam 0.2 mg/kg intramuscular or intranasal/buccal, diazepam 0.3 mg/kg IV or per rectum — a maximum of two benzodiazepine rounds, since further doses add respiratory depression without efficacy.
- Second-line doses: fosphenytoin or phenytoin 20 mg/kg (phenytoin infused no faster than 1 mg/kg/min with ECG), levetiracetam 40-60 mg/kg, valproate 40 mg/kg; phenytoin is avoided in absence or myoclonic status, where valproate fits the syndrome.
- Refractory options: midazolam infusion 0.1-0.4 mg/kg/hour after loading, or thiopentone or propofol anaesthesia with intubation and electroencephalography.
- Metabolic screen in the fitting child: bedside glucose, sodium, calcium, magnesium; hypoglycaemia gets 2 mL/kg of 10% dextrose, and severe hyponatraemic convulsions warrant 3% saline.
- Pyridoxine rule: any infant under two years in refractory status receives pyridoxine 100 mg IV — cessation of seizures within minutes is diagnostic of pyridoxine-dependent epilepsy.
- Neonatal line: phenobarbitone 20 mg/kg IV is first-line after benzodiazepines (many protocols place it first), reflecting the developing brain's pharmacology.
Walking the clock minute by minute
A four-year-old with known epilepsy on carbamazepine has been convulsing for six minutes when the ambulance arrives. Minute zero to five already passed at home, so the emergency department starts at stage two tempo: airway positioning, oxygen, bedside glucose (normal), intravenous access, and lorazepam 0.1 mg/kg — seizure continues; a second lorazepam dose at 0.1 mg/kg at minute twelve — brief slowing, then recurrence. At minute eighteen, fosphenytoin 20 mg/kg equivalents runs in over the standard rate with cardiac monitoring while the team draws levetiracetam; the seizure stops at minute 25. The child who does not stop enters refractory protocol: midazolam loading then infusion, intubation, and electroencephalography, both to titrate suppression and to catch the non-convulsive status that hides behind a "post-ictal" child who never truly wakes.
Running parallel to the drugs is the cause hunt: fever with a first seizure in a toxic child means lumbar puncture after stabilisation (meningitis), a blank medication history suggests non-adherence with subtherapeutic levels, and a first-ever seizure in an infant earns electrolytes, calcium, and the pyridoxine thought. Febrile status epilepticus — the commonest single form in children — still deserves the full algorithm plus meningitis consideration below the age of the febrile seizure boundary.
Where students slip
Two timing errors dominate: waiting thirty minutes before escalating (the five-minute definition exists precisely to prevent this), and giving a third and fourth benzodiazepine dose instead of changing class at minute twenty — the algorithm's central discipline is two doses, then a different mechanism. The dose facts are heavily examined and often half-remembered: lorazepam 0.1 mg/kg capped at 4 mg, midazolam 0.2 mg/kg by the non-intravenous routes that outperform no access, fosphenytoin 20 mg/kg. The syndrome-matching point is subtle but scored: phenytoin in a child with juvenile myoclonic epilepsy in myoclonic status worsens it; valproate or levetiracetam is the answer that matches the epilepsy syndrome to the drug. Finally, the unwaking child after control is an electroencephalogram question — non-convulsive status is the diagnosis you cannot see.
Frequently asked questions
How is status epilepticus defined currently?
A seizure lasting five minutes or longer, or recurrent seizures without recovery of consciousness — an operational definition that triggers treatment far earlier than the historical 30-minute criterion.
Which benzodiazepine doses are first-line?
Intravenous lorazepam 0.1 mg/kg (maximum 4 mg) or midazolam 0.2 mg/kg intramuscular, buccal or intranasal, repeated once only before escalating.
What second-line agent and dose follows failed benzodiazepines?
Fosphenytoin or phenytoin at 20 mg/kg (phenytoin no faster than 1 mg/kg/min with ECG), or levetiracetam 40-60 mg/kg, or valproate 40 mg/kg, matched to the epilepsy syndrome where known.
When is pyridoxine given in status epilepticus?
In any infant under about two years with refractory seizures — 100 mg intravenously, with immediate cessation supporting pyridoxine-dependent epilepsy.
What is non-convulsive status epilepticus?
Ongoing electrographic seizure activity without motor convulsions, suspected in a child who fails to wake after convulsive status, confirmed by electroencephalography.