Paediatric Seizures – PEM Induction

Author: Shrouk Messahel / Editor: Liz Herrieven / Questions: Frances Copp / Codes: / Publication Date: 11/12/2018

The seizing child is truly a scary thing to behold. If you work in the Paediatric ED, you will, at some stage, come across a child who has had a seizure, is recovering from a seizure, or is actively seizing. It is, after all, one of the more common presentations to the ED being the cause of about 1-2% of attendances, with 5% of all children less than 16 years having experienced one.

There are a few different types of seizure and knowing which type you are dealing with will guide you to what to do in the ED. Most children who’ve had a seizure will have experienced a self-limiting simple febrile convulsion, and you will find it hard to guess, given their full recovery and seemingly normal state in front of you. At the other end of the spectrum convulsive status epilepticus (CSE) is the most common neurological life-threatening medical emergency in children with an incidence of around 20 per 100,000 children per year. It is the fourth most common reason for admission to PICU. It carries a significantly increased risk of mortality and irreversible morbidity. Knowing the APLS guidelines on treatment of this medical emergency is a must for any ED doctor, as treatment targeting resolution is key to reducing mortality.

How do you know it was a seizure?

Children are great. They come with their own ‘1:1 nurse’ aka mum or dad. They are witnesses to these abnormal neurological events and from the history you can get a very clear understanding if an event was a true seizure or not.

Aspects to look out for in the history to suggest a seizure include:

  • rhythmic tonic or tonic – clonic movements
  • lateral tongue biting
  • eye deviations with flickering
  • incontinence (in the older child)
  • post-ictal phase

A child who has no post-ictal phase is unlikely to have had a seizure. Rapid recovery from an event more likely suggests an alternative diagnosis.

Be sure to have a look at Heart Alliance for some useful videos from Dr Whitehouse on differences between reflex anoxic seizures/ syncope and true seizures.

If it doesn’t seem classic or straight-forward, there are a few things in the ED you can do to make sure you have covered the common alternatives that could mimic a seizure. Children who have experienced a paroxysmal event will need a cardiac work-up so an ECG is essential, as is exploring the history for any cardiac symptoms or any significant family history of cardiac events. Conduction abnormalities are the main issue here, and, just to make it harder, a normal ECG doesn’t exclude cardiac conduction abnormalities. A high clinical suspicion and a conversation with your senior or a Paediatric Cardiologist would be the next step.

An unconscious child is a whole different kettle of fish. This child, although critically unwell may not be seizing and separate guidance is available for this group of patients. Look at the RCPCH guidelines on the Management of children with acute decrease in conscious level.

Febrile Convulsions

These are a very common type of seizure which occur in feverish children between 6 months and 5 years of age.  They are usually a single, generalised, short-lived tonic-clonic seizure with a short post-ictal phase after which the child returns to their normal neurological state.

Be careful – sometimes details are lost in handover. Look for a documented fever (on the ambulance sheet or the GP notes). If a child has no documented fever immediately before or during the seizure it is highly unlikely to have been a febrile convulsion.

This is a short video of a child having a febrile convulsion. You can see the moment when the seizure stops and the return of a more regular breathing pattern in the post ictal phase.

The main scope of your consultation in a child who has had a simple febrile convulsion is to reassure the parents, advise on fever control and make sure you have found a focus of infection. NICE guidance on fever in children under the age of 5 years is a good guide if no focus of infection can be found.

Most parents will have been very scared watching their child have a convulsion and their main question to you will be ‘Is it going to happen again?’. The risk of recurrence is around 33% but can be higher if they have a family history of febrile convulsions. It is also higher  the younger the child is when they have their first febrile convulsion.  The risk of their child having afebrile seizures is around 1% (quite similar to the general population), but again higher if there is a family history of epilepsy, or if they have had a complex febrile convulsion (5% risk).

Complex febrile convulsions can happen in a child of any age. By definition they occur multiple times in a 24 hour period and can be generalised or focal.  These kids need a work-up including, when appropriate, an LP, as meningitis or encephalitis can be the cause. If you suspect meningitis or encephalitis and the LP is delayed, don’t delay in administering IV antibiotics and/or IV acyclovir.

Also beware the child who does not wake up or does not return to normal after a seemingly ‘simple’ seizure – these children need urgent investigations including metabolic screening and imaging of their head. As above, have a look at the RCPCH guidelines on management of an unconscious child.

Seizure Management

Ok. So you are in the ED and get a pre-alert that a fitting child is coming. Preparation is the key: get yourself and your team ready. If the seizure is prolonged or if the child has received benzodiazepines, you may be faced with a poorly ventilating child who may or may not still be seizing.  Follow the APLS algorithm as it guides you on a stepwise medication ladder to try and terminate the seizure. If the child has received one or two doses of benzodiazepine pre-hospital, start the algorithm at that point – don’t go back and give another two doses. A common reason why children need ventilatory support and/or intubation in the ED with seizures is that they have had too much benzodiazepine.

So the child arrives in your ED. Below are a few pointers to determine cause and severity:

  • What’s the temperature (Is this a febrile convulsion?)
  • What’s the blood sugar? (Hypoglycaemia is an easily reversible cause)
  • How long has the seizure lasted? (A child seizing for more than 3 minutes is unlikely to spontaneously stop.)
  • Past history of seizures especially during this episode.

Convulsive Status Epilepticus (CSE) is defined as a continuous seizure lasting longer than 30 minutes, or a cluster of seizures with no neurological recovery in between.  This is a true medical emergency and carries a significant mortality and morbidity. The APLS Status Epilepticus Guideline is time and medication focused. Don’t forget the basic medical assessments and interventions: ABC and ‘DEFG’ (Don’t Ever Forget the Glucose) are all vital, whilst another member of the team is drawing up the appropriate medication.

A few notes on the algorithm:

First-line: Benzodiazepines

There are numerous benzodiazepines for CSE, which can all be given safely and effectively. If you have venous (or intraosseous) access, then give IV lorazepam – it’s more likely to stop the seizure and with less risk of respiratory depression. It’s stored in the fridge, and needs drawing up with a really big needle – it’s viscous! There’s a shortage at the moment, but hopefully that’ll be resolved soon.  Buccal midazolam is a good alternative if you have no access – give half into each side of the mouth and massage the cheeks. Rectal diazepam is the least likely to work of the three and is the most difficult to give. Only give two doses, ten minutes apart. More doses are unlikely to stop the seizure (as GABA receptors will be saturated), yet are likely to cause respiratory depression and worsen the existing hypercarbia from ineffective ventilation. A good tip is to announce to the team (and parents) “Now we wait 10 minutes before giving more drugs, as per the algorithm” – this helps to prevent any pressure to give the next dose too soon. Use the 10 minutes to get access, assess for a focus of infection, prepare the next medication, etc. If respiratory depression or apnoea does occur because of the benzodiazepines, don’t give flumazenil, as the child might suddenly seize again. Manage the respiratory depression with ventilation.

Second-line: Phenytoin

Phenytoin has been used as second line treatment for ages, and there is evidence to suggest that Levetiracetam (Keppra) may be a better alternative for CSE.  Until the APLS guideline committee have reviewed the evidence, phenytoin remains the recommended drug after benzodiazepines. There are a few things you need to know about phenytoin before you give it:

  • it needs to be given by slow infusion (over 20-30 minutes). There have been several deaths related to giving it as a bolus or as a continuous infusion.
  • side effects include rashes, extravasation injuries, ‘purple glove syndrome’, and cardiovascular abnormalities including arrhythmias and hypotension.
  • intralipid is used for serious cardiovascular toxicity
  • as it follows zero order kinetics (remember that?), the line between therapeutic effectiveness and toxicity is fine. Levels can be monitored with references set by your local lab.

Other second-line agents:

Paraldehyde: This remains a good medication to use in adjunct to IV second-line therapy. It is given rectally.

Levetiracetam: There is growing evidence to suggest this is a good second line agent. Recent multicentre studies EcLiPSE and ConSEPT have shown no statistical difference between giving phenytoin or levetiracetam in CSE. There are more studies near completion in the USA also looking at this. What these studies have shown is that giving a loading dose of levetiracetam as a short infusion in the ED is safe.

RSI with Thiopentone: by the time you get to this stage, the child has been seizing for at least 45 mins and is at massive risk.  Potential complications of seizing for that long include neuronal death, cerebral oedema, rhabdomyolysis and pulmonary oedema to mention only a few. At this point you’ll need all the help you can get. Contact your regional children’s critical care transport team or PICU along with your hospital’s duty anaesthetist. A paralysing agent should be used for induction, but not in ongoing care – escalating the anticonvulsant medication is key.

The APLS Status Epilepticus algorithm should be followed regardless of whether or not a child has a fever or what the underlying cause of the seizure is; treatment of both can go hand in hand.

Afebrile Seizures

Causes of afebrile seizures are numerous. Once again a good history is key in establishing the type of paroxysmal event especially if it is the first presentation.  Always do a blood glucose measurement as hypoglycaemia is a readily treatable cause (with consideration given to performing a hypoglycaemia screen).

If a child (over the age of 6 months) comes to the ED having had their first afebrile convulsion and they are neurologically well with no obvious cause on history or examination, aside from the standard ED observations (including BP) and a blood sugar, no other investigation in the ED is likely to help or yield useful results.  Having said that, in the infant, NAI must always cross your mind. Look for other clues like unexplained bruising or a vague non-consistent history.

Things to look out for in the history and examination which may alter your management include:

  • History inconsistent/unexplained bruising (NAI)
  • Caf au lait spots (think neurofibromatosis)
  • Ash leaf spots (think tuberous sclerosis)
  • Meningism (think meningitis/intracranial bleed)
  • Dysmorphic features
  • Hepatomegaly or jaundice (think metabolic disease)

Intracranial imaging in the ED should be reserved for those children who you think may have an urgent and potentially reversible neurological cause to their seizure, for example children with VP shunts, signs of raised ICP, bleeding tendencies, sickle cell disease, malignancy, post-head injury etc.

So, in summary, paediatric seizures are common and most are self-limiting.  Take a careful history and think of red flags.  Bring your “A” game to status epilepticus, and look at the guidance available.

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