Status Epilepticus in Children

Status epilepticus is the most common childhood medical neurological emergency.

The Neurocritical Care Society guidelines define status epilepticus as:

“A seizure with 5 minutes or more of continuous clinical and/or electrographic seizure or recurrent seizure activity without recovery between seizures.”

The majority (approximately 90%) of seizures will spontaneously terminate within four minutes, with no intervention required. Convulsions lasting more than five minutes, however, are unlikely to cease spontaneously and will usually require treatment to aid termination. Convulsions lasting longer than 30 minutes are associated with an increased risk of death and long-term neurological consequences.

Aetiology

The causes of status epilepticus in children include the following:

Structural:

Intracranial tumour
Cerebrovascular disease
Head injury
Cortical dysplasia

Infectious:

CNS infection (meningitis, encephalitis)
Tuberculosis
Cerebral malaria

Metabolic:

Metabolic disturbance (e.g. electrolyte imbalance, glucose imbalance, organ failure)
Metabolic disorders
Anoxic injury
Mitochondrial disorders

Toxicity or drug-related:

Low or high level of anti- seizure medication
Withdrawal of anti-seizure medication
Other drug/alcohol overdose
Neurotoxins and poisons

Inflammatory:

Autoimmune disorders
Neurocutaneous disorders

Genetic:

Dravet syndrome
Ring chromosome 20
Angelman syndrome
Fragile X syndrome
Rett syndrome
Trisomy 21

Primary survey and resuscitation

Any child presenting with status epilepticus should be managed using the standard ABCDE approach:

Airway:

Maintain the airway and manage secretions
Red flag – airway obstruction not responding to jaw thrust or airway adjunct

Breathing:

Administer high-flow oxygen
Consider intubation and ventilation
Red flag – respiratory failure

Circulation:

Establish IV/IO access
Check vital signs
Red flag – signs of shock

Disability:

Assess conscious level and check pupils
Don’t forget the glucose!
Red flags – symptoms or signs of raised ICP, encephalopathy or focal neurology

Exposure:

Expose and examine thoroughly
Red flags – purpuric rash, puncture marks or signs of head trauma

APLS red flag algorithm

If any red flags are detected in the primary survey, then it is likely that the child will need to be intubated and ventilated urgently and anaesthetic or intensive care support should be obtained urgently.

Reversible causes should be identified and treated during this period:

Correct hypoglycaemia with 3ml/kg 10% glucose
Treat hyponatraemia less than 125 mmol/l with 3-5 ml/kg of 3% sodium chloride
Aim for normothermia
Treat meningoencephalitis with IV ceftriaxone and acyclovir
Check ammonia
Consider specific antidotes
A LUMBAR SHOULD NOT BE PERFORMED

Indications for a CT head scan include the following:

New prolonged seizure
New focal seizure
Refractory seizures
New neurological deficit
Suspected raised intracranial pressure
Suspected space-occupying lesion
Ventriculoperitoneal shunt in situ
Trauma
Possible non-accidental injury

APLS status epilepticus algorithm

The current APLS algorithm for the treatment of the status epilepticus in children is as follows:

Step 1 (5 minutes after start of convulsion):

In a child that has been convulsing for 5 minutes or more an initial dose of benzodiazepine should be given:

Lorazepam 0.1 mg/kg should be given IV or IO if vascular access is available
Buccal midazolam 0.5 mg/kg or rectal diazepam 0.5 mg/kg can be given as alternatives if no vascular access is available or in the pre-hospital setting

Step 2 (5 minutes after 1^st benzodiazepine):

If the convulsion continues for a further 5 minutes a second dose of benzodiazepine should be given, and senior help should be summoned.

Step 3 (5 minutes after 2^nd benzodiazepine):

At this stage senior help is needed to reassess the child and advise on management.

Anaesthetic or intensive care support should be obtained urgently, as the child may need anaesthetising and intubating if this step is unsuccessful.

Give 40 mg/kg of levetiracetam IV (maximum 3 g) over 5 minutes. This should be given even if the child usually takes oral levetiracetam.

If seizures continue despite loading with levetiracetam then termination with induction of anaesthesia and intubation is expected. However, if the advanced airway team is not yet prepared and the ABCDE assessment is stable, then:

If not already on phenytoin, then a phenytoin infusion should be set up (20 mg/kg IV infusion over 20 minutes)
If already taking phenytoin, then phenobarbitone can be used in its place (20 mg/kg IV infusion over 20 minutes)

Rectal paraldehyde at a dose of 0.8 ml/kg of the 50:50 (maximum dose 20 ml) may still appear on individual seizure management plans and can be given in some circumstances.

Step 4 (10 minutes after finish of infusion):

If the child is still convulsing at this stage, then a full paediatric emergency team, including an anaesthetist, paediatric intensivist, or other practitioner with advanced paediatric and airway skills must be present.

Rapid sequence induction is recommended. Ketamine is considered the safest choice of induction agent. Thiopentone and propofol are sometimes used by experienced practitioners but can cause profound hypotension and rarely cardiac arrest. All induction agents should be used with a rapid-onset muscle relaxant, e.g. rocuronium.

Investigations

The following investigations should be considered to aid the diagnostic work-up of a child presenting with status epilepticus:

Blood tests – full blood count, urea and electrolytes, bone profile, magnesium, glucose, liver function tests, arterial blood gas, c-reactive protein
Blood cultures if febrile
Brain imaging – CT head or MRI
Lumbar puncture for CSF analysis – BUT ONLY WHEN STABLE
Blood and urine for toxicology
Metabolic screen – serum ammonia, lactate, plasma amino acids, urine organic acids
Anti-seizure medication levels if on treatment
Electroencephalogram (EEG)

Key updates

Notable updates in 7^th edition APLS include:

Pre-hospital treatment with buccal midazolam or rectal diazepam is endorsed at step 1
There is now a shorter 5-minute interval between benzodiazepine doses in steps 1 and 2
The second line drug has now changed to levetiracetam
In step 4, if the team are ready, they should proceed to RSI with either ketamine, thiopental or propofol. If the team are not ready either phenytoin or phenobarbital can be given and if immediately after completing this, if the child is still convulsing, the team should proceed to RSI.

Header image used on licence from Shutterstock

Thank you to the joint editorial team of www.mrcemexamprep.net for this article.