College Answer

a)
 A convulsion associated with an elevated temperature greater than 38°C.
 A child younger than six years of age.
 No evidence of central nervous system infection or inflammation.

 No evidence of acute systemic metabolic abnormality that may produce convulsions.
 No history of previous afebrile seizures.
 Generalised rather than focal.
 Short (< 15 min) rather than prolonged.
 Single rather than multiple.

b)
Benzodiazepines:

a) Diazepam – 0.1 to 0.3 mg/Kg IV over 2 – 5 minutes, maximum 10 mg per dose - or

b) Midazolam - 0.1 – 0.3 mg/kg bolus IV, can be given in an infusion 0.1 to 0.5 mg/Kg/hr.
o Advantage – rapid onset, terminates seizures under most circumstances, can be administered by other routes-IM, P/R, nasally.
o Disadvantage – excessive sedation, respiratory depression. May need airway control including intubation.

Phenytoin:

15 – 20 mg/kg IV bolus dose at rate of < 50 mg/min, 5 – 10 mg/kg maintenance daily 12 hours after.
o Advantage - preventing recurrence of SE for extended periods of time.
o Disadvantages – Slow onset of action up to 30 minutes, Hypotension, cardiovascular collapse, ataxia, nystagmus, blurred vision, and coma.

Barbiturates

– Phenobarbitone: 10 – 20 mg/Kg initially up to 40 mg/Kg if needed to control seizure activity.
o Advantage – more effective than phenytoin in controlling seizure activity.
o Disadvantage – severe respiratory depression, requires monitoring in HDU/ ICU, may require intubation and ventilation.

Thiopentone: 2 – 3 mg/kg bolus IV, repeat as needed.
o Advantage – most potent of any epileptic agent.
o Disadvantages – IV anaesthetic agent hence requires intubation and ventilation for administration, hypotension.

Propofol: 1 – 3 mg /Kg bolus, 1 – 3 mg/Kg/hour.
o Advantage – quick onset and offset.
o Disadvantage – very few studies to support its use in status epilepticus, propofol infusion syndrome at high doses, requires intubation and ventilation.

Sodium Valproate - Loading dose: 20 – 40 mg/kg followed by a continuous I.V. infusion of 1 – 5 mg/kg/hour.
o Advantages – studies showing effective in 78% cases refractory to diazepam, phenytoin and phenobarb, less sedating than barbiturates.
o Disadvantages – fatal hepatotoxicity can occur hence contra-indicated in significant hepatic impairment.

Levetiracetam – Newer anti-epileptic agent – 15 (5 – 30) mg/kg bolus dose, 25 – 50mg/kg maintenance in two divided doses.
o Advantage – very good safely profile.
o Disadvantage – Limited published data in paediatric age group.

Discussion

By the most recently attempted definition, febrile convulsions are "a seizure occurring in childhood after one month of age, associated with a febrile illness that is not caused by an infection of the central nervous system". There are actually two definitions, which differ slightly. In brief summary, these are seziures which occur in the presence of fever and in the absence of any other good reason for seizures, in an age range variably described as under 6 years, 1 month to five years, 3 months to five years, and six months to six years.

The Royal Children's Hospital Clinical Guidelines has a slightly different age range to both of the above, and closely resembles the college answer. Clearly, both must have the same source.

The list of criteria for the diagnosis of simple febrile convulsions:

• Fever >38.0°
• No history of neonatal seizures
• No previous unprovoked seizures
• No focal neurological features (i.e. generalised seizure)
• Tonic-clonic seizure
• Occurs after 6 months of age, and before the age of 6
• Lasts less than 15 minutes
• Occurs only once per episode of febrile illness.

The list of criteria for the diagnosis of complex febrile convulsions:

• Fever >38.0°
• No history of neonatal seizures
• No previous unprovoked seizures
• Focal seizure
• Tonic-clonic seizure
• Occurs after 6 months of age, and before the age of 6
• Lasts longer than 15 minutes
• Occurs several times within the same episode of febrile illness.
• Incomplete recovery after 1 hour.

The college then goes on to ask for five drugs – one from each class, as well as their dose, their advantages and disadvantages. Such a question lends itself well to a tabulated answer.

Much of this information can be found it its raw untreated form in Slater's chapter on neurological emergencies in children, from Oh's Manual.