You Snooze, You Lose? #smaccUS The Child with Altered Consciousness

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As a part of the #smaccMINI workshop back in Chicago in 2015, I spoke about the approach to the child with an altered conscious level. The podcast is below along with a brief summary of the talk. The guidance below is relevant to the previously well child who presents with altered consciousness, rather than (for example) a child with known hydrocephalus and a VP shunt who presents more drowsy than usual – such patients usually have specific care pathways including rapid imaging.

Take Home Message 1: We Need to Wake Kids to Assess Them

3Sometimes in kids, just as in adults, altered consciousness represents serious pathology. This can be problematic for us to untangle because typically PED presentations peak in the early evening, which means that we see many of our patients around or after bedtime. Some will have fallen asleep in the waiting room. However, it is imperative that you wake children to assess them (not necessarily first thing in the consultation – sometimes in younger children you’ll get more information from examination if you can complete most of it before they wake up and start screaming – but before you discharge the child).

Waking children can be tricky – but parents/carers may have ways. You will need to explain why an assessment of conscious level is so important as waking a sleeping child may be counterintuitive to exhausted parents.

Parents or carers may report that a child is “lethargic” or “just not right” – be very careful before dismissing this. Trust parents’ instincts around their child’s condition in comparison with normal and remember that if conscious level is difficult for healthcare practitioners to quantify1, it’s even harder for non-medically trained people.

This video shows my godson being woken by his parents (included with permission). Note how, towards the end of the video as he is walking, he seems to be displaying some abnormal posturing – he is a neurologically normal and healthy child. Assessing normality can take time but it is really important.

What do we mean by “assessing” children with reportedly reduced conscious level?

Firstly, we can try to quantify consciousness using GCS, AVPU or potentially the paediatric four score scale (PFSS)2. GCS recorded by the same clinician can be useful for serial assessment, but we should consider using paediatric adaptations of GCS particularly for non-verbal children3.

Then there are some core obs we should measure in patients with reportedly reduced consciousness – the RCPCH guidelines recommend measurement of  HR, RR, SpO2, BP, and temperature every hour.

We should also ensure we record a blood sugar level within fifteen minutes of the child’s arrival.

What should we ask about in the history?

As well as asking about the features of the current presentation and the chronology of symptoms, there are some specific things we should remember to ask about:

  • The presence of fever, vomiting, and/or headache
  • Whether the conscious level has been suddenly decreased, trending downwards, or fluctuant
  • Any history of recent trauma, however minor
  • What access the child might have to medications (including prescription and non-prescription medications of family and household members) and any history of drug or alcohol use
  • Family history: ask specifically whether there has been any family history of sudden, unexpected deaths, in childhood particularly but early adulthood might be relevant too. Consanguinity between parents may also be relevant.

What blood tests might we think about doing?

Not all children need blood tests, obviously, but in the child with a confirmed reduced conscious level, there are some specific tests which might be useful to us:

  • Glucose – at the very minimum this should be checked!
  • Blood gas (venous or capillary gases will give a good guideline and starting point for many values)
  • Ketones
  • FBC, U&E with Ca2+
  • Blood for culture
  • Urine clean catch for analysis
  • LFTs
  • Ammonia

Take Home Message 2: We Need to Protect the Unconscious Child

9Until you know what’s going on, it’s reasonable to assume that there might have been a primary insult to the brain and as such our first priority should be to prevent secondary brain injury. That might mean any of a variety of interventions targeted towards protecting airway and breathing (and preventing airway obstruction – you might need to consider rapid sequence intubation). Be aware that even the child without apparent airway compromise may have coexisting hypoventilation and may need ventilation to support inadequate breathing.

As with head injured patients, we should target normality: normal BP (for age), normal oxygenation (avoiding hypoxia), normal CO2 (avoid hypo or hyperventilation), normoglycaemia. You can imagine the sorts of interventions which might be required to achieve these targets. In addition we should assume that the ICP is raised and aim to optimise CSF outflow: nurse patients at 20-30deg head up and avoid neck lines if possible.

Take Home Message 3: Think 5MF

10I like this acronym for thinking about important treatable causes of reduced conscious level in kids.

Of course there are other causes but I find this approach gives me a structure for thinking about and treating potentially deadly or treatable conditions.

It’s up to you how you remember 5MF – I find the graphic helps, and the fact that five starts with F reminds me of the 5Ms to one F.

There’s more information on each of the causes – and how you should approach them – below.

 

18MICROBES: TREAT IT

The first thing on our list should be intracranial infection because it is relatively common, potentially deadly, and easy to treat. We shouldn’t be waiting for lumbar puncture before treating this: these patients should be covered with a cefalosporin and aciclovir (because we can then cross the diagnosis off the list for the next few hours until subsequent doses are due). Remember to consider adding dexamethasone if you are thinking of bacterial meningitis4 – we are giving this because evidence from high income countries suggests treatment with steroids prevents hearing loss and neurological sequelae rather than because there is any known mortality benefit.

 

METABOLIC: MEASURE IT17

Metabolic diseases (as in, inborn errors of metabolism) tend to present at two different time points:

  1. neonates (more likely absence/complete blockage of metabolic pathway)
  2. later in life, often precipitated out by intercurrent illness (in which case usually partial/incomplete blockage of metabolic pathway)

Metabolic disease is something you should think about in the presence of hypoglycaemia and it is these patients who may also have a family history of neonatal death (or unexplained, unexpected death in childhood or early adulthood), or consanguinity between parents.

Remember, HYPOGLYCAEMIA is NOT A DIAGNOSIS. You can read more about hypoglycaemia in children here.

The key tests we need to think about are ammonia levels, glucose (lab confirmation helps) and ketone levels. You may need to contact your lab to find out the procedures for processing a sample for ammonia which used to involve obtaining ice from somewhere. The treatments for a child presenting de novo with a presumed metabolic illness are reasonably simple.

Firstly, SWITCH IT OFF: we want to prevent further accumulation of toxic metabolites so the child should be nil by mouth, with dextrose maintaining their blood sugar.

  • If Ammonia >200 micromol/L – treat with sodium benzoate 250mg/kg in 15ml/kg 10% dextrose over 90mins (you made need your oncall pharmacist for this one!)
  • If Glucose <2.6 mmol/L – before treating, try to obtain blood and urine for a hypoglycaemia screen, then correct with 2ml/kg 10% dextrose.
  • If Ketones are normal – nonketotic hypoglycaemia is signifiicant for metabolic disease

Beyond this point, we should be contacting the local metabolic centre for advice. If the child has a known metabolic condition their parents/carers will usually bring details of their emergency regime but the British Inherited Metabolic Disease Group Emergency Guidelines are excellent.

20MISCHIEF: IMAGE IT

By mischief we mean something space-occupying within the cranial vault. We need to determine whether there is something – spontaneous intracranial bleed, hydrocephalus, traumatic bleed, venous sinus thrombus, tumour? – raising the ICP. Pay particular attention for Cushing’s effect: bradycardia with hypertension suggests impending herniation and probably warrants preemptive treatment with hypertonic saline or mannitol.

The quickest and easiest imaging modality in most centres is CT and while this might not give the soft tissue detail required for diagnosis of tumours you can usually determine enough to make a provisional diagnosis and rule out an acute bleed. Having a friendly chat with your radiology colleagues about what is available is often helpful.

19MEDICATIONS: CONSIDER IT

We do start to see illicit drug use among teenage patients although alcohol causes many more presentations. We should, however, be wary of attributing reduced conscious level to “just alcohol” – we should still check a blood sugar as hypoglycaemia or hyperglycaemia may coexist with apparent alcohol intoxication. That said, the diagnostic value of tox screening in the ED is very limited as most tests take so long to come back the patient is well and truly gone from the ED by the time results are available.

In younger children, there are a number of “one pill kills” – their low body weight can mean that even a single pill of adult medication can prove fatal. Notable culprits include:

  • oral hypoglycaemics
  • opioids
  • TCAs
  • beta blockers
  • calcium channel blockers
  • antimalarials
  • antiarrhythmics
  • theophylline
  • salicylates

The history of available medications at home is therefore incredibly important. Of course, older children may intentionally ingest medications as attempted suicide; toxidrome may suggest the underlying agent but we have to consider it in all unconscious paediatric patients. Keep an eye out for Nat Thurtle’s toxicology talk from smaccMINI in Dublin, coming soon – I’ll add the link here when it’s released.

22FITS: CONTROL IT

Of course generalised tonic-clonic seizures cause reduced consciousness but these are usually obvious (and we generally know how to treat the fitting child). Don’t forget in these cases that fits may coexist with any of the pathologies mentioned above.

Non-convulsile status is much more difficult to identify: it’s a diagnosis to consider if the patient has an increased heart rate, agitation and sweating – bedside EEG helps although I’m not sure how available this is to most Emergency Departments.

21MIGRAINE: RELIEVE IT

The last cause I want you to think about is acute confusional migraine5. Patients may present with a variety of apparently neurological symptoms including confusion and amnesia6. Acute confusional migraine can present in adults but is more common in children and adolescents – I have seen at least two cases in my clinical career.

ACM is pretty rare and really a diagnosis of exclusion BUT what I want you to remember is that it is incredibly simple to give analgesia to these patients – and this may well treat the underlying migraine (or other pain the patient is experiencing). Above all – be kind 🙂

So, for children with a reduced conscious level…

  • Wake to assess
  • Protect the brain
  • Think 5MF: microbes, metabolic, mischief, medications, fits and migraine.

vb

Nat

@_NMay

Further Reading

Before you go please don’t forget to…

References

1.
Gill M, Reiley D, Green S. Interrater reliability of Glasgow Coma Scale scores in the emergency department. Ann Emerg Med. 2004;43(2):215-223. [PubMed]
2.
Czaikowski B, Liang H, Stewart C. A pediatric FOUR score coma scale: interrater reliability and predictive validity. J Neurosci Nurs. 2014;46(2):79-87. [PubMed]
3.
Reilly P, Simpson D, Sprod R, Thomas L. Assessing the conscious level in infants and young children: a paediatric version of the Glasgow Coma Scale. Childs Nerv Syst. 1988;4(1):30-33. [PubMed]
4.
Brouwer M, McIntyre P, Prasad K, van de. Corticosteroids for acute bacterial meningitis. Cochrane Database Syst Rev. 2013;(6):CD004405. [PubMed]
5.
Schipper S, Riederer F, Sándor P, Gantenbein A. Acute confusional migraine: our knowledge to date. Expert Rev Neurother. 2012;12(3):307-314. [PubMed]
6.
Rota E, Morelli N, Immovilli P, et al. ‘Possessed’: Acute Confusional Migraine in an Adolescent, Prevented by Topiramate. Case Reports in Neurology. 2012;4(3):240-243. doi: 10.1159/000346208

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