Highlights from the Virtual Colloquium – 14th Annual Update in Paediatric Emergencies Day 1

It’s been a long time since I’ve been at a conference, either in-person or virtually. Something that was once a regular part of my professional life has, like so many things, become a distant memory.  

Even though here in Australia we have been largely spared the brunt of the first (and second, and third) waves of the pandemic, we seem to be doing our level best to catch up and we have still seen disruption to our academic meetings with border closures and smaller outbreaks disrupting plans time after time. 

In late September I had been intending to be in sunny Noosa, Queensland for the 14th Annual Update on Paediatric Emergencies (run by the Colloquium conference group) but as COVID would have it, I instead spent three half days sitting on my balcony here in NSW feeling slightly guilty for not being in the trenches of the ED alongside my colleagues, dialled in to the first virtual iteration of the meeting.

The talks on Day 1 were pretty impressive, actually, despite eye-wateringly traditional slide sets (where is Ross Fisher when you need him?!). There were three talks – Dental Trauma, Vaping and Metabolic Emergencies. By far the most interesting was the talk on vaping, so I’ve devoted more coverage to that and put it at the end, even though it was the middle talk. Here’s what I learned from the speakers.

Richard Widmer – Paediatric Dental Trauma

The biggest take-home message from this talk was “put dental in your differential”. Dr Widmer made the point that in many cases we consider dental trauma separately from other trauma patterns, whereas in truth it can form part of the constellation of injuries seen in a number of presentations.

At the centre he works at, a standardised dental triage document has helped to record accurately examination findings in ED, as well as providing example images of common injuries and guidance around reimplantation for avulsed teeth. 

With regard to dental presentations to the paediatric ED, he tells us, these fall into four main categories.

1. Trauma – to both primary and young permanent dentition

2. Facial swellings – seen in infants, children, and adolescents

3. Children with special needs – and deteriorating behaviours which might incorporate dental issues

4. The left field presentations – from the funny to the serious and the downright bizarre

Dr Widmer started with the left field presentations: an unusual presentation he described as common (though I’ve never seen it!) is the child with foreign body or bodies pushed up into hard palate. These may stay in place for weeks without detection as children may be too afraid to confess to their parents. Subsequent collection of debris and inflammation may complicate the diagnosis, giving a bizarre appearance on examination.

He also described how his colleagues had helped with removal of a ring from a thumb (with distal injury presumably precluding the undertaker method) by using a dental drill where ring cutters had failed. A strip of metal was slid underneath to protect the digit.

Other unusual presentations included a child with their tongue stuck in the opening of a drink bottle: at presentation they had considerable oedema of the tongue, described as feeling “rock hard” – and while the offending bottle was cut away the team used water spray to protect the oral mucosa from overheating secondary to cutting implements – a helpful technique to have tucked away in your mental toolbox.

Lastly, penetrating trauma from toothbrushes underpinned an appeal to strongly discourage children from walking around with anything in their mouths. There are a couple of published case reports around these; this one describes the toothbrush lodged near the carotid artery. https://pediatrics.aappublications.org/content/118/4/e1284.long

There was a timely reminder that non-accidental injury may have orofacial manifestations – as with other NAI presentations, history may be vague. 

Verucca vulgaris can be seen intraorally in children who suck or bite their fingers where common warts are located but oral warts are unusual at dental margins or on the soft palate: in this case consider other forms of abuse (including sexual), where condylomata might be the responsible pathogen.

The mainstay of what we consider to be dental presentations concerns dental injuries and orofacial trauma usually involves:

  • Hard tissues (teeth and supporting bones)
  • Soft tissues (gingivae, mucosa and skin)
  • Or a combination of both

Studies report >50% young children are affected by dental injuries, with peak incidence at 1-2yrs, 8-10yrs and early adolescence.

Conversely, Dr Widmer urges us to consider head injury in presentations of dental trauma. He suggests we consider including maxilla and mandible imaging in our requests for head trauma imaging as these components are often omitted and thus dental/orofacial trauma is missed or its diagnosis delayed.

In the case of significant dental injuries it is important to account for the missing/broken part of the tooth (accidental inhalation is rare) – it may be within wounds, clothing or elsewhere.

Reimplantation is something we think about in the ED but should only be undertaken for permanent teeth, rather than primary teeth.

How do you know it’s a primary tooth?

You usually tell by the age of the patient. For primary teeth, the crown is supported by a root that is twice as long as the crown; this is physiologically absorbed before teeth fall out (which is why we aren’t used to seeing it as teeth are lost naturally). 

Primary teeth are not reimplanted because

  • Attempted reimplantation can damage the permament tooth
  • The amount of treatment required (follow-up, GA, splinting) is not worth it!

If you’re not sure whether the tooth is primary or permanent, place it in milk (or coconut water, saline, or a sports drink).

It is also helpful to understand the chronological eruption of primary teeth, to determine whether they have indeed been knocked out – or just haven’t erupted yet

In the case of an avulsed permanent tooth, it needs to be reimplanted ASAP

  • Keep it moist – milk is best, but any fluid will do (water is least useful but better than nothing)
  • Hold by the crown, clean with milk, gently reinsert it, and consult the dental team – they will usually splint it in place
  • Check tetanus status, give a booster where appropriate
  • Antibiotics are not usually needed but might be indicated if there is significant soft tissue injury or if an avulsed permanent tooth is replanted.
  • Give analgesia and recommend a soft diet. 
  • There may be long term negative effects on the child – encourage families to follow up with their regular dental practitioner and stress the importance of long term monitoring following dental injuries. 

It may take up to three years for complications to manifest. 3-4 years after maxillary trauma, incisors may present non-vital with chin swelling, and this is mistaken for infection (the history of previous trauma is key here, so be sure to ask).

This leads us nicely on to: infections. Once again we are urged to have dental in our differential for orofacial infection (and the advice was to treat with co-amoxiclav rather than flucloxacillin)! 

Primary herpes is frequently seen and mistakenly treated with antibiotics; appropriate management is hydration, analgesia and rest. The patient presents with red gingivae which are very painful – but the condition is self-limiting, lasting 10-14 days. 

Lastly, extra-oral injuries may also have oral components so be sure to look in the mouth for all patients with facial injuries (eg dog bite to face). Mandibular and orofacial fractures are uncommon in children but not unheard of.

Image credit: Richard Widmer

Carolyn Ellaway – Metabolic Disease in the Paediatric ED

Echoing a brilliant talk delivered by DFTB’s Dani Hall at Resus at the Harbour back in 2017, A/Prof Ellaway opened with a reminder that although inborn errors of metabolism are individually rare they are collectively numerous – so we need to have them in our differential for all sick children (and some sick adults too).

Simply described, inborn errors of metaolism may result from;

  • Not enough or impaired activity of a specific enzyme
  • Not enough or impaired activity of a specific transporter protein

These errors lead to build up of substrate before the block and/or a deficiency of the product afterwards, and understanding this can help us make sense of how we make the diagnosis. It’s worth remembering that substrate build up may secondarily inhibit other chemical reactions – for example, in maple syrup urine disease (substrate build up – leucine); fatty acid oxidation disorders (reduced product – ketones); methylmalonic aciduria (secondary inhibition of urea cycle with ammonia build up).

When we are trying to make the diagnosis, there may be genetic clues: consanguinity, family history, recurrent miscarriages/stillbirths/neonatal deaths are important things to ask about.

We often wonder whether we can work out a pattern of inheritance from this info; most inborn errors of metabolism are autosomal recessive with only a small amount having x-linked inheritance. Mitochondrial disorders can be maternally inherited if coded within mitochondrial genome. Autosomal dominant metabolic disease is rare.

You might be aware that some metabolic diseases are screened for in the heel prick “Guthrie” test – but it is important to know for Maple Syrup Urine Disease in particular that the newborn screen being normal does not preclude the diagnosis, so if you are suspicious, still pursue a diagnosis of metabolic disease.

We should also be alert to particular clinical clues: acute metabolic encephalopathy, chronic metabolic encephalopathy, encephalopathy with intractable seizures, and diffuse hepatocellular disease are the top presentations that should boost inborn errors of metabolism up our list of differentials.

Acute metabolic encephalopathy is one of the most common presentations of inborn errors of metabolism to the ED. Classically, the patient is a full term baby, with normal gestation and delivery and a symptom-free period before they become unwell and present to ED.

These patients present with deterioration for no apparent reason – most have a septic workup in ED but will not respond to symptomatic therapy. There may be an identified relationship between presentation/symptoms and feeding, or reports of the baby having an unusual odour. 

The interval between birth and clinical symptoms is highly variable; it is longer if there is some residual enzyme activity. Inborn errors of metabolism may present days, weeks, months or years (even into adulthood, at time of metabolic stress).

When we are thinking about inborn errors of metabolism, there are some important baseline metabolic investigations we can do in ED

  • Urine (smell, ketones, send for amino acids and organic acids)
  • Blood/plasma (blood gas, glucose, ammonia, EUC, LFTs, FBC, lactate. The metabolic team may ask for plasma carnitine and plasma amino acids. If the patient presents with seizures, specialists may suggest obtaining paired blood and CSF amino acid levels).
Image credit: A/Prof Carolyn Ellaway

Many of these patients present with a good-going metabolic acidosis, and further analysis can help delineate the underlying problem.

If there is an increased anion gap:

  • Is it organic acid accumulation? Eg MMA
  • Is it due to lactic acidosis? This implies tissue hypoxia or mitochondrial disorders
  • Is there accumulation of ketones? This might suggest DM, maple syrup urine disease, organic acid or ketone body utilisation defects

If there is a normal anion gap:

  • Is this due to loss of bicarb?
  • Is there renal tubular dysfunction? This is seen in galactossaemia, tyrosinaemia

Patients presenting with hyperammonaemia may have early respiratory alkalosis, so seeing this in a baby with acute encephalopathy should trigger ammonia measurement

Image credit: A/Prof Carolyn Ellaway

The mainstay of treatment for inborn errors of metabolism is broadly the same:

  • Resuscitation and respiratory support
  • Start disease-related treatment early
  • Stop anything triggering it (usually this means stopping feeds)
  • Prevent catabolism and promote anabolism
  • Provide enough glucose to prevent hypoglycaemia
  • Remove toxins – either using medications (but ammonia lowering drugs [such as sodium benzoate] won’t work if the ammonia crazy high) or through renal support
  • Hyperammonaemia – treat as an emergency. Outcomes and prognosis are dependent on lowering the ammonia 
  • Support enzyme activity (this might mean administration of cofactors eg IM high dose Vit B12 in MMA)

These patients are at ongoing risk of metabolic decompensation with routine childhood illnesses so each needs an individualised action plan after diagnosis.

Image credit: A/Prof Carolyn Ellaway

Gary Williams – Vaping

This was a really interesting talk, not least because I hadn’t particularly considered the health implications of vaping beyond its use in smoking cessation. Dr Williams talked about three different dimensions of vaping;

  1. Vaping-related injuries
  2. The health effects of vaping as a practice
  3. The wider public health implications of vaping

Firstly, what exactly are electronic cigarettes? Apparently they were originally invented in 2003 by a Chinese pharmacist as a safer way to aerosolise a nicotine containing liquid for smokers. There has been an exponential increase in use since then, including among adolescents, and vaping now represents an estimated >$10bn market.

e-Cigarettes have a battery, a heating element and chamber or pod for liquid to be vaporised. The vaping liquid (or “vape juice) may contain: nicotine (of variable concentration), a solvent (glycerol or propylene glycol or similar) and flavouring – and there are thousands of flavourings available, fruit menthol and mint being the most popular.

Image credit: Gary Williams

Early generation e-Cigarettes were produced by cigarette companies but the market has largely been taken over by independent companies. Vaping significantly reduces exposure to toxic substances and cancer risk if a cigarette smoker makes the switch to e-Cigarettes. Public Health England says vaping is less than 5% as harmful as a tobacco cigarette: but there’s more context to that figure that we need to think about. 

Up to 2016, there have been 195 reports of eCigarette explosion injuries involving face, arms, and groins. These presentations have include fractures to cervical vertebrae, palatal fractures, damaged teeth, thermal burns, chemical burns and wounds.

In addition to burns from exploding e-Cigarettes, there’s a more sinister injury pattern of particular concern to paediatricians – eVALI (eCigarette or vaping associated lung injury.

This case series was published in the Lancet in 2019 and describes the phenomenon: 60 patients, mostly young adult males, presented over a 3 month period. >50% were admitted to ICU and ¼ ventilated.

Thy were treated with O2, antibiotics and steroids, with most responding to steroid within days. 30% of the patients were discharged on O2 and >50% had ongoing cough two weeks after discharge. The exact aetiology remains unclear – it’s thought to be a chemical pneumonitis from an inhaled toxic contaminant, but it remains unclear which one (or ones). Many of these patients had obtained vaping liquid from “informal sources” (from friends or via the internet) rather than from vaping shops.

So what about the health effects of vaping itself?

In the lung – vaping has been shown to inhibit ciliary beating, inhibit mitochondrial activity, increase pro-inflammatory mediators, release proteases into airways, inhibit CFTR-mediated Cl- secretion and induce airway dehydration. Acrolein (a metabolite of cyclophosphamide) is thought to be responsible: it arises from thermal degradation of hydrocarbons in vape juice. 

In this Am J Physiol study: transient lung inflammation and gas exchange disturbances were seen; the authors felt this “reflects epithelial dysfunction induced by vape that might impair respiratory fluid regulation and pulmonary gas exchange.” This seems to bear out in adolescents: a Californian study showed increased odds ratio of bronchitis symptoms in those who used vaping regularly compared with those who didn’t.

In the cardiovascular system, effects on endothelial function and nitrous oxide generation are seen alongside platelet dysfunction – these effects are all less powerful than those seen with regular cigarettes, but we don’t know the long term effects as yet. Data from Italy did show that if you’re a hypertensive smoker and use eCigarettes as a cessation aid, you could lower your BP if you could reduce or quit smoking by vaping.

Immunological changes are seen too – vaping reduces macrophage antimicrobial function in vitro; however exposure to vape fluid also increased the virulence of MRSA while reducing multiplication rate. In mice, exposure to vape fluids made mice less effective at clearing pneumococci. Generally, use of vape liquid seems to inhibit clearance of viruses, making colonisers more lethal, and increasing mortality in animal models.

Brain effects are seen too – nicotine increases dependence tendencies to other substances in this mouse model. The study shows the priming effect of nicotine; if nicotine is stopped for 24h priming effect is lost.

We don’t know for sure yet, but it’s likely we will see stronger effects in adolescent animals, including humans. And while vaping is touted as a solution for nicotine addiction in smokers, in dependence vaping is probably just as effective as currently available smoking cessation treatments. Two RCTs have shown that abstinence from nicotine is infrequently achieved, and the majority become just as dependent on the vape in the end.

There are significant social drivers for smokers to switch to vaping though: it allows them to manage their dependence in a way that is healthier, cheaper and easier to do (smoke free laws); and some have successfully used vaping as a smoking cessation aid.

There’s no question, though, that it’s not existing smokers who are being targeted by the majority of advertising around vaping. JUUL, a vape-producing company now does no conventional advertising; having slashed their budget they now purely advertise on social media: chiefly Twitter, Instagram and YouTube). Data from the US shows we’ve been seeing a reduction in cigarette smoking in adolescents anyway, which has not been affected by eCigarette introduction, but we are now seeing a growing proportion of eCigarette-only use in this group seemingly independent from cigarette use (ie among “never smokers”).

We know there are risks of nicotine use in adolescents: it is injurious to the developing brain, there are implications for dependence, and it is a gateway to eventual tobacco use (this plays out in this paper). This BMJ study shows for the first time in years an increase in adolescent smoking across the UK, US and Canada.

Image Credit: Gary Williams

As such, the public health debate is current, strongly debated and controversial: and paediatricians need to be involved and up to date. There’s an ideological UK vs US split: in the UK, public health has been focused on benefits for current smokers, while the US is focused on youth effects (unequivocally opposed to eCigs). New Zealand has taken a more pragmatic and practical stance, with regulation of vaping and advertising – and it seems to be working. In Australia, legislation around the sale nicotine containing substances changed on 1st October and you can no longer buy nicotine-containing liquid for vaping without prescription.

I don’t know what the answer is to this public health problem, but it’s likely we might see more eVALI in the ED coming years. We might also start to see longer term health implications too – and whether exhaled vape “smoke” poses a risk of transmission of respiratory viruses from person-to-person might turn out to be relevant too…

Lots to take in from Day 1…

So, that’s what happened on day 1 of the PEM Colloquium: more to come from my notes from days 2 and 3!

VB

Natalie May



Cite this article as: Natalie May, "Highlights from the Virtual Colloquium – 14th Annual Update in Paediatric Emergencies Day 1," in St.Emlyn's, October 15, 2021, https://www.stemlynsblog.org/highlights-from-the-virtual-colloquium-14th-annual-update-in-paediatric-emergencies-day-1/.

Posted by Natalie May

Dr. Natalie May, MBChB, MPHe, MSc, PGCert Medical Education, FRCEM, FACEM is section lead for paediatrics and medical education. She is an Editorial Board Member of the St Emlyn’s blog and podcast. She is a specialist in Emergency Medicine (Australia) and a Specialist in Emergency Medicine with Paediatric Emergency Medicine (UK). She works as Staff Specialist in Prehospital and Retrieval Medicine with the Ambulance Service of New South Wales (aka Sydney HEMS). She also works as aStaff Specialist, Emergency Medicine, St George Hospital (South Eastern Sydney Local Health District). Her research interests include medical education, particularly feedback; gender inequity in healthcare; paediatric emergency medicine. You can find her on twitter as @_NMay

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