Monday, 19 December 2016

If you can't decide between turkey and goose... Pertussiolitis and other animals - when a child has noisy breathing

Recently I learned a good way to find the answer to a question.  It happened like this-

On a walk in Sheffield I saw this strange bird:

Unable to find this creature described in a ‘Birds of Britain’ book, I posted the picture to Facebook and commented that (to me) it looked like a cross between a turkey and a goose.  Most other Facebookers were similarly unfamiliar with the species but within a short period of time, I received a response from my niece who declared the bird to be a Muscovy duck.  After quickly confirming this to be true, I asked how she recognised this bird which is not native to the UK.  The response that came back was simply that she had searched the internet for "birds which look like a cross between a turkey and a goose". 


I had the chance to complete this lesson, for myself in a clinical context, shortly afterwards when faced with another unfamiliar animal, this time in the form of a baby with an ambiguous presentation.  The child had developed a cough and feeding difficulties and had now become wheezy.  Preemptively, my diagnostic centres had skipped forward to the disease that I thought I merely needed to confirm: bronchiolitis.   This mental process was interrupted by a cough from the child, and what a cough it was.  It went on and on and on…  At the end of the period of coughing, the child’s face was properly red. The mother informed me that more often than not a spectacular vomit followed these paroxysms of cough.

With the new possibility of whooping cough suggesting itself, I examined the child with a new mission: confirm findings that are consistent with pertussis infection.  I was therefore, properly annoyed to find a wheeze which I felt was more in keeping with bronchiolitis.  Faced with this puzzle and remembering my niece’s methods, I asked the internet and found that, while not a typical feature of pertussis infection, wheeze has been well described in a large number of cases of children with whooping cough. (1)

This case reminded that, as primary care clinicians, we don’t really diagnose infections- we diagnose syndromes.  Bronchiolitis, for example, is not RSV infection.  Bronchiolitis is a syndrome of wheeze, poor feeding and cough which can lead to severe respiratory distress, apnoea and feeding or respiratory failure.  RSV is one possible cause amongst many untreatable viruses.

Similarly, despite what I was once taught, croup is not caused by parainfluenza virus.  Any virus can cause the upper airway swelling that leads to barking cough, possibly stridor and varying degrees of respiratory distress.

Just to keep me on my toes, children seen to present from time to time with features of multiple syndromes.  The most common bedfellows are croup and viral induced wheeze.  When faced with a child who has a barking cough and a wheeze, one initially questions whether the noise is in fact a stridor (and rightly so).  If it is a wheeze, then it is a wheeze.  If the child has both croup and viral induced wheeze, ther is no point trying to limit the diagnosis.  Just get on and treat both.  It occasionally causes a bit of confusion if the child needs admission.  I think that some junior doctors take the referral of a child with the diagnosis of viral wheeze and croup together to be a sign of uncertainty, or perhaps dementia.

I would suggest that perhaps wheeze is not a feature of whooping cough but that it is possible for a baby to have bronchiolitis at the same time as whooping cough, both caused by pertussis infection.  It doesn't really matter though, since the cause of the infection is only of interest if it can be treated, or transmission prevented.

There are so many infectious causes of noisy breathing in children. Here is a simple guide to what’s what and what to do about it:

Many thanks to my niece for teaching me what the internet is for.

Edward Snelson

Disclaimer: I take full credit for inventing the use of evidence based medicine in the consulting room.

  1. Taylor Z.W. et al, Wheezing in children with pertussis associated with delayed pertussis diagnosis, Pediatr Infect Dis J. 2014 Apr;33(4):351-4.
Acknowledgement: This is a slightly different version of a post which I wrote for the Network Locum Blog earlier this year.

Wednesday, 7 December 2016

How to spot a made up number and what to do with it

Paediatrics is absolutely full of made up numbers - we rely on them every day.  If you think about it, many of the numbers that we have been given to work with are too conveniently rounded to be believable.  I don’t want to spoil the movie for you, but you have been lied to an awful lot.

The question is then. what do we do with the made up numbers?  Knowing where they come from is the key to the answer to that question.

Lie number 1 – For a baby, the normal milk intake is 150ml/kg/day

This one goes way back.  It actually comes from a number of fluid ounces per pound per feed which was a rough guide produced back in the bad old days.  The thing is that no-one has ever done a robust study finding out how much the average breast fed baby takes in 24hrs because there has been no good way of checking.  Not only is the number 150 a bit conveniently round and decimal, no one can tell you what the 5th and 95th centiles are. These facts would be essential for you know if a baby is taking an abnormal amount of feed.  The reality is that the mean (which this may or may not be) is not what we need to know in the first place if we are trying to assess whether feeds are too much or two little.

Luckily, you don’t need to know.  The best way to tell if the feed is enough is by the effect it has on the baby.  If it is too little, the baby won’t grow.  If it is too much the baby might exhibit signs of reflux disease due to overfeeding.

This brings us back to the question of what to do with a made up number.

Just because a number has never been validated by research doesn’t mean it’s not at all valid.  This particular number has been in use for decades now and is a useful landmark even if we don’t know which side of the truth it sits on.  The fact that it is accepted practice tells you that it has value - if it was frankly misleading, someone would have noticed.  The 150ml/kg/day number does at least tell us whether a child might be having too much or too little feed.  Knowing that you’re nowhere close to that figure is also useful.  For example, if a baby has faltering growth and is found to be taking 50ml/kg/day of milk, then lack calories would be a reasonable diagnosis.

Lie Number 2 – A normal heart rate between the ages of 0 and 1 is 110-160

For many years there have been three main lists of ‘normal values’ for physiological values in children.  We rely heavily on these as warning signs when it comes to recognising ill children.  Those reference ranges were all different for a reason – they were decided upon by experts rather than being based on definitive evidence.

Two published papers (1,2) have shown that the numbers in pooled population data conflict in places with the normal values in these reference ranges.  Notably however, the authors of these papers acknowledge that (I paraphrase) there is no such thing as a normal value when it comes to heart rate or other parameters in children.  There are just too many variables each of which can have a huge effect: sleep, activity, fear, pain, fever...  You get the idea.  Do we need to have normal values for a three year old who has just eaten an ice cream but is upset because a sibling has taken a toy off them?  I would love to have an app that takes into account variables like tiredness and temperature.  In the meantime, what I have is a lot of numbers that give me some idea of what normal might be, if only there was such a thing as normal in a child.

In many ways, the studies referenced show that consensus or expert opinion can be pretty good at coming up with the answers.  The correlation between the study findings and the made up numbers is remarkable.

I find it liberating to know that a heart rate can’t be treated as a piece of information out of context.  After all, we should always be looking at the child.  If their numbers are lying to you, hopefully their smile will tell you the truth.

Lie number 3 – a baby should lose no more than 10% of their birth weight in the first week of life

By now, you should be able to spot these numbers for what they are:

  • Made up
  • Still useful
  • Only helpful in context

It’s that simple.

The lies go on and on.  I couldn’t even begin to list the drug doses that are either plucked out of nowhere or at best based on some research where a number plucked from nowhere was shown to work.  Adrenaline for cardiac arrest is in the former group amazingly.  Fortunately for most drugs, we are protected by a wide therapeutic margin of error.

I like numbers.  Unfortunately children are themselves hugely variable and rarely normal.  I certainly wasn’t.

Edward Snelson
Chaos conspiricist

Disclaimer - If you can't trust numbers, what can you trust?  Certainly not me.


  1. O'Leary, F at al, Defining normal ranges and centiles for heart and respiratory rates in infants and children: a cross-sectional study of patients attending an Australian tertiary hospital paediatric emergency department, ADC, 2015
  2. Fleming et al, Normal ranges of heart rate and respiratory rate in children from birth to 18 years of age: a systematic review of observational studies, Lancet 2011;377:1011–18

Wednesday, 23 November 2016

Empirical Paediatrics – What is the best rehydration fluid for children with gastroenteritis?

When children have an uncomplicated gastroenteritis, dehydration is the enemy.  There are lots of things that we can give children to drink, but what is the best rehydration fluid to keep children out of hospital?

There are many things said about which fluid is best.  NICE recommends water or milk to maintainhydration but says to avoid fruit juice and carbonated drinks. (1)  In children who require rehydration they recommendoral rehydration solution (ORS).  In my previous post I listed 10 myths about gastroenteritis and used that to point out the NICE recommendations.  This advice conflicts with a study published in the JAMA (2) this year which showed that half strength apple juice was more likely to work than oral rehydration solution.

So, I’ve had another look at the basis of the NICE recommendation that we should “use ORS solution to rehydrate children” and the reason given is: “Although there were no clinical trials on the effectiveness of fluids other than ORS solution in the treatment of dehydration, the GDG considered that the composition of such fluids was generally inappropriate.  In dehydration due to gastroenteritis, both water and electrolyte replacement is essential, and non-ORS solution fluids do not usually contain appropriate constituents.  ORS solution was considered the appropriate fluid for oral rehydration.”

In other words, there was no evidence to support other fluids than ORS and there was reason to suspect that they are not ideal.  The trouble with two plus two is that it only equals four if there are no unknown variables.  The empirical approach dictates that instead of trying to figure out what should be true, we only believe what can be evidenced.  That removes the risk that there are unknown unknowns.  In the case of keeping a child hydrated, there is a big wildcard- the child.
One of the more interesting results of the apple juice vs oral rehydration fluid study was that the effect (half strength apple juice being more effective) was more pronounced in children over the age of 2 years.  I think that phenomenon is easily explained by two things:
  • Children develop the ability to choose for themselves
  • Oral rehydration fluid has a disgusting taste

When looking after children, we often have to choose between the treatment that is best on paper and the treatment that the child will take.  In this case, taste beats logic hands down.

So what do you do when your guideline tells you not to do something?  I would say that we need to recognise that while guidelines have strengths, they also have weaknesses.  NICE and other similar guidelines require a huge amount of searching through evidence, appraising applicability of the literature, and ultimately a decision to be made by people, with everything that entails.  What we get from that is a load of recommendations from people who have worked really hard to give us the best answers that they can come up with.   Now that there is evidence for apple juice, this will no doubt be considered when the guidelines are revised - a process that will take a very long time.

Even when a guideline is up to date, it is up to us to apply it to the child in front of us.  For example, where is the guideline for treating gastroenteritis in a child with autistic spectrum disorder?

Will flat cola be the next thing to be shown to be effective after all?  Who knows?!  What I do know is this: we now have an evidence base for a rehydration fluid that is palatable, readily available and doesn’t require a trip to the pharmacy or the doctor’s surgery.  That has got to be a win for de-medicalising and a victory for self-care.

What do you do if the child doesn’t like apple juice?  Don’t give them that then.  What is clear is that (within reason) the best rehydration fluid for a child is the one that they will take.

Edward Snelson
Eventual empiricist

Disclaimer - I was taught the theory of empricism by my daughter.  If this is all wrong, it's her fault.

  1. Diarrhoea and vomiting caused by gastroenteritis in under 5s: diagnosis and management, NICE CG84, Published date: April 2009
  2. Freedman, S et al, Effect of Dilute Apple Juice and Preferred Fluids vs Electrolyte Maintenance Solution on Treatment Failure Among Children With Mild Gastroenteritis, JAMA. 2016;315(18):1966-1974

Thursday, 13 October 2016

Why bronchiolitis doesn't get better with inhalers and how understanding "why?" is better than "do that!"

There was interesting debate this week about using inhalers for bronchiolitis.  The interesting features included how heated it became (there was mild name calling and much "prove it" involved, rated PG) and how confident people were in expressing their views on social media about their differing clinical practice.  (Take it from me that you should be fairly sure of yourself before you put something out onto the interweb.)  To me what was most interesting was that the views, despite being polar opposites, where seen as fact.  I am going to assume that all involved want to practice the best possible medicine, but someone must be wrong mustn't they?

What do the guidelines say?  The American Academy of Pediatrics and the UK's National Institution of Clinical Excellence along with other institutions, have produced guidelines in the past few years, specifying that beta agonists and ipratopium should not be used, so why are such debates still happening?  I think that there are a few reasons.  One of these is that for medics, knowing what to do is not as powerful as knowing why, especially when it comes to changing practice.  For me, understanding a disease is much more effective as a learning process than being told, "This is the disease and this is the treatment."   I suppose it is because I already understood the reason why I was doing what I was doing (even if the understanding was flawed), so a diktat is not as powerful a persuader as a new and better understanding.

There is a perpetuated myth regarding beta-receptors and infants.  This myth comes from early studies that failed to find evidence of beta-receptors in infants.  Since then, (as early as 1987) research of better methodology (3) has proven that these receptors are there from birth.  The myth persists because (just as the news reports plenty of crises but not so many resolutions) we are often told things, but rarely does anyone untell us something.

Perversely, the beta-receptor folklore has done us no favours when it comes to trying to understand bronchiolitis and viral wheeze.  The uncertainty created by this myth makes clinicians think that a lack of beta receptors has caused the lack of response to salbutamol.  In fact, the child would respond just fine if only they had bronchospasm.

In bronchiolitis, there is no bronchospasm so salbutamol does not help.  In viral wheeze, ipratopium is a poor treatment and the old myth about ipratropium leads some to believe that ipratropium is the first line treatment for this age group when what they really need is plenty of salbutamol if they really do have bronchospasm.

When discussing the management of wheeze in infants, I often get the impression that people believe that bronchiolitis is just what you call viral wheeze in a child under the age of 12 months.  In fact this is not true.  Bronchiolitis is a separate entity, with different histopathology and a unique clinical pattern of illness.  There is a gradual unset of symptoms, peaking at day 3-4 and beginning to resolve at day 7-10.  Doesn't sound very spasmy does it?

Of course the confusion arises from the fact that both bronchiolitis and viral wheeze are caused by a viral illness.  They can both occur in a child around the age of 12 months old and they cause similar symptoms.  There is however a subtle but helpful difference in the way that they present.

The reason for this difference is a difference in mechanism.  While bronchiolitis and viral wheeze share a cause, the pathology is different because the effects on the airways are different.

I suppose that since it is unrealistic to think that all uncertainty can be removed, the question remains, what is the harm in trying a bronchodilator in all every case, just in case?  Here are a few possible reasons why it is going to make things worse if it isn't going to make things better:

It's always difficult when two illnesses have so much overlap, but there are genuinely good reasons to avoid unnecessary treatment for bronchiolitis.  Hopefully understanding why bronchodilators don't work helps the thinking clinicians to decide for themselves, rather than just being told what to do by guidelines.

Edward Snelson

Disclaimer:  I would like to express my appreciation to the children who allowed me to perform lung biopsies on them during their wheezy episodes.  Science thanks you.

  1. Clinical Practice Guideline: The Diagnosis, Management, and Prevention of Bronchiolitis, American Academy of Pediatrics, October 2014
  2. NG9 Bronchiolitis in children: diagnosis and management, NICE, June 2015
  3. A Prendiville et al., Airway responsiveness in wheezy infants: evidence for functional beta adrenergic receptors, Thorax. 1987 Feb; 42(2): 100–104.

Thursday, 29 September 2016

The Internet Has Ruined Everything (Easter Egg - Things You need to Know About Chickenpox)

Things were so much easier when life consisted of being told something by an authoritative figure, after which you could go on indefinitely, believing that fact to be true.  That is how most of medicine has been taught and learned.  The trouble is that much of what we are told is either untrue or unfounded.  Of course to ruin it all, there in now a way to check up on what you are told.  That has made life very difficult for anyone in a medical educational role.

Let me give a non-medical example to illustrate my point.  A few years ago, after watching the film Guardians of the Galaxy, I was commenting on the way that Vin Diesel's role as an animated character was a departure from his roots in gritty action thrillers.  My daughter politely told me that this was untrue, since he had played the title role in the rather brilliantly animated Iron Giant film (1999).  Since I am big and she was little, I felt it only reasonable to set my daughter straight, pointing out that said film was intelligent and Vin Diesel was a hard core meat head who at that stage had not yet begun his career as an actor in any meaningful way.

In my childhood, that would have been the end of the matter.  Faced with such an argument I would have accepted my wrongness or at least agreed to differ with said parent.  This is no longer how these things play out and I was confronted immediately by my wiki-error and proved wrong.

Imagine if we should start to do that with what we think we know about anything in medicine.  Take chickenpox for example: Let's explore some of the things that you might have been told about one of the most common childhood infections.

1. Chickenpox (varicella) is a benign, self limiting viral illness

While that is mostly true, Chickenpox has a surprisingly bad track record.  here are a few chickenpox stats that may surprise you:

  • Hospital admission rate of up to 6 per 1000 cases (2)
  • Mortality of 2-3 per 100,000 cases (1,2)
  • Risk of death four times higher in infants (2)
  • 70% of deaths occur in otherwise healthy cases (2)

What causes these admissions and deaths?  It turns out that chickenpox has an alarming number of potential complications.  The most common complication of chickenpox infection is secondary bacterial infection.  This can be the obvious culprit: stapphylococcus aureus.  However probably more commonly and certainly more significantly, group A streptococcal (GAS) infection is the real enemy.  Children with chickenpox are particularly prone to this infection which accounts for the majority of varicella associated deaths.

Other acute and serious complications include encephalitis and pneumonia.  The morbidity and mortality of all of these has been significantly reduced where varicella vaccination has been introduced.

2. You should not give Ibuprofen to children who have chickenpox

If you haven't come across this chestnut then I apologise for being the bearer of bad and rather confounding news.  There has been a controversy about ibuprofen and chickenpox for a long time.  Around the same time that Vin Diesel was voicing the Iron Giant (1999), there was a case controlled study published in which a significant number of children with chickenpox developed necrotising faciitis. (3)  For whatever reason, the authors suspected a link with ibuprofen use and indeed found an association.

This has led many to recommend that ibuprofen is not used as an antipyretic for children with chickenpox.  I believe that the case for this avoidance is based on flawed information.  Firstly, there is the confirmation bias of the original work.  Some of the cases in the study were the same cases that led the authors to ask the question: 'Is there a link?'  Secondly, although it was a case controlled study, the children in the control group had less fever.  Could that be a confounder when looking for an association with an antipyretic one wonders...  Indeed, at the time ibuprofen was a prescribed drug.  In many ways, you could say that the conclusion could easily have been 'Children with chickenpox who were sick enough to see a doctor had a ten times greater risk of developing necrotising faciitis.'  Finally, the association (if there was one) was mainly with ibuprofen being given after there were signs of invasive GAS infection.

The case for avoiding ibuprofen in children with chickenpox is far from convincing.  I certainly don't think that anyone should be accused of bad medicine if they have used ibuprofen for a child with uncomplicated chickenpox.

My advice is this:  Use paracetamol as first line treatment for fever in children with chickenpox.  If a second antipyetic is being considered, ask 'Why does this child need a second medicine?'  Symptoms of uncomplicated chickenpox are normally controllable with one antipyretic.  If the child is unwell despite this, consider the possibility of a secondary infection.

3. Chickenpox causes a rash for a week and a fever for a few days and then it gets better

Except when it doesn't...

While the vast majority get better without complications, chickenpox causes a suprising number of children to get a rather unusual neurological condition: cerebellitis (also called post viral ataxia).  This is a post-infective phenomenon which tends to present in the weeks immediately after the infection, often as the lesions are well crusted or even fading.  Typically the child presents with ataxia.  Other symptoms include clumsiness and difficulty maintaining posture.  Nystagmus and other cerebellar signs may be obvious.  There is no treatment needed but children should be assessed by a specialist to confirm the diagnosis.  Imaging is not needed as long as there are no atypical features and the symptoms begin to improve after a couple of weeks. (4)

So, the internet ruins any attempt to hold onto our faith in simple facts.  This is partly because facts are rarely simple and often wrong.  All of the three bold statements above were things that I was told and believed at some point in my career.  Finding out the truth takes a little looking and a lot of thinking but you get to find out some worthwhile things along the way.  Or, you could just let an expert tell you the facts...

Edward Snelson
So very not an expert

  1. Atkinson, William (2011). Epidemiology and Prevention of Vaccine-Preventable Diseases (12 ed.). Public Health Foundation. pp. 301–323. ISBN 9780983263135
  2. Heininger, U., Varicella, The Lancet, Vol 368, Iss 9544, 14–20 Oct 2006, p1365–1376
  3. Zerr DM. et al., A case-control study of necrotizing fasciitis during primary varicella, Pediatrics. 1999 Apr;103(4 Pt 1):783-90.
  4. Nussinovitch M. et al., Post-infectious acute cerebellar ataxia in children, Clin Pediatr (Phila). 2003 Sep;42(7):581-4.

Sunday, 4 September 2016

Gastroenteritis in Children - Ten Myths

Vomiting and diarrhoea in children is usually caused by viral gastroenteritis.  There are lots of myths surrounding gastroenteritis and how best to manage it.  I find myself repeating things that I was once told years ago and have to check from time to time whether the 'fact' is in fact based in any reality.  When I find out that it was all a myth, it makes me feel so much better when I later hear other people who hold those same myths to be true.  Hopefully, between us we can dispel a few of them.  Here are a few non-truths that I regularly come across:

1.  It's just a virus.  I know that I said it is usually a viral infection in children and that is true.  However that should not fool people into thinking that it is a benign illness.  Even in well nourished children, dehydration is a real risk and every year previously healthy children with gastroenteritis suffer renal failure and other consequences of severe dehydration.  Avoiding dehydration makes for most of the dos and don'ts of gastroenteritis.

2.  Paracetamol should be avoided because it makes the child vomit.  Not so.  What is more nauseating: 5 mls of liquid vitamin P or fever and abdominal pain?  Giving paracetamol is likely to help resolve the vomiting and make the child feel more like they could cope with drinking a few sips of water.  Certainly, children often do vomit shortly after being give paracetamol but when it works, it is well worth it.

3. You shouldn't give milk to children who are vomiting.  The best fluid depends on two factors.  One factor is the level of hydration.  If a child is at risk of or is becoming dehydrated then oral rehydration fluid (ORF) is recommended.  The second factor is the question of what the child will take.  Oral rehydration is really important, so better a bottle of milk that is drunk than a bottle of ORF that is continually refused.  The important thing to avoid is the list of drinks that will make matters worse.  Milk is not on that list.  Just because milky vomit is nasty compared to when the child is drinking clear fluids doesn't mean you should avoid milk if that is what they will take.  Milk contains carbs and electrolytes and for babies it is the fluid of choice.

4.  Flat cola is great for rehydration.  What makes a poor rehyration fluid?  Acidity to worsen gastritis as well as hyperosmolality and added chemicals that will drive diarrhoea.  Flat cola ticks all of these boxes which is why it gets a special mention in the 'don't do it' bit of the NICE guidelines for gastroenteritis in the under five year olds. (1)

5.  You can't give antiemetics to children.  Now we are getting into more controversial territory.  Antiemetics such as prochorperazine and metoclopramide (where would I have been as a house officer without these two drugs?) are traditionally avoided in ill children due to the risk of dystonic reactions.  It has threfore been the case that gastroenteritis has always been in that category of illnesses that just has to get better on its own.  That may be why the world of paediatrics has failed to reconsider this view despite the appearance of newer and safer antiemetics.  There is good evidence for example that ondansetron reduces vomiting and may aid rehydration (2).  So why don't we use that when a child is failing to rehydrate orally?  NICE considered this when writing its guideline and noted that ondansetron is also associated with increased diarrhoea.  The answer was therefore that it could not yet be recommended, but possibly with more research, ondansetron will be recommended in specific circumstances.

6. You can't give antidiarrhoeals to children.  Again, NICE considered the pros and cons of this option.  There are various types of antidiarrhoeal medicines, each of which was decided against in turn, mostly on the basis that there was no evidence for benefit.  In the case of loperamide, there is reasonable evidence that it does help (3).  So what's the problem?  Loperamide is not licensed for use in children in the UK (and I think the same is true in the USA and Australia but I'm not sure about elsewhere).  However, the BNFc does list doses and acknowledges the license issue.  I don't intend to medicalise self limiting gastroenteritis, but if I thought it would help, it is good to know that it is therapeutic option.

7.  A period of starvation can resolve vomiting or diarrhoea.  The only clinical value to an enforced period of starvation for a child is that it is a great way to diagnose MCADD.  Witholding food or drink will not change the course of viral gastroenteritis.  However, some children do have underlying, yet hidden metabolic disorders of energy production.  These children have often had no manifestaion of their disorder because they have never run out of immediately available energy.  When they are unwell and rely on ketones, everything goes wrong and hypogylcaemia can come on profoundly and unexpectedly early into a period of fasting.  Any ill child who is not getting calories and who becomes subdued or agitated should have a blood glucose checked.

8.  It's a 24 hr bug.  In fact who knows how long it will last.  I don't believe that you can make something go wrong just by saying a thing.  For example, I am very happy to walk around at work commenting on how lovely and quite it is and enjoy seeing the superstitious flinch at this.  However predicting the length of a gastroenteritis is a recipe for perplexed parents.  Vomiting usually settles by day 3 and diarrhoea should be at least much improved by day 7.  Should be...
If diarrhoea is not resolving at day 7 then consider doing a stool sample.

9.  It's probably food poisoning.  Thankfully not.  The vast majority of vomiting and diarrhoea in children is viral gastroenteritis.  Bacterial infections are more likely if the child has been to an area with endemic infection.  A history of consuming foods that are likely to have been contaminated is also important.  A sudden onset of vomiting does not imply food poisoning though.  Norovirus for example typically causes sudden and severe symptoms.

10.  Dehydration requires intravenous fluids.  Rehydration is best provided through the gut, not a vein.  Although guidelines are changing in order to avoid dangerously hypotonic fluids, intravenous rehydration will always be risky.  Every effort should be made to achieve oral hydration.  If this fails then nasogastric rehydration has a good evidence base.

Of course these are only the myths that I used to believe before my faith was destroyed by reasoning and evidence.  Do you have any of your own?  If you know of a wrong but popularly held belief to do with gastroenteritis then please post it in the comments below.  Cheers!

Edward Snelson
Grade 'O' in Care of Magical Creatures at O.W.L.

Disclaimer: It feels a bit strange to be in agreement with so much of a NICE guideline.  I may be coming down with something.

  1. Diarrhoea and vomiting caused by gastroenteritis in under 5s: diagnosis and management NICE guidelines [CG84]
  2. Szajewska H et al., Meta-analysis: ondansetron for vomiting in acute gastroenteritis in children, Aliment Pharmacol Ther. 2007 Feb 15;25(4):393-400.
  3. ST Li et al., Loperamide therapy for acute diarrhea in children: systematic review and meta-analysis, Database of Abstracts of Reviews of Effects (DARE)

Thursday, 25 August 2016

Hunting the focus of infection

Finding a focus for infection in a child is one of those things that we all know we ‘must do’.  That can be more difficult than it sounds.  Often, no focus is easily found and then the questions are, “Where do I look?  What if I can't find a focus?  I don’t know when to stop looking!”

How many children are seen with significant temperatures, where the eardrum is not easily seen?   On probability alone, the focus is more likely to be a hidden upper respiratory tract infection rather than something else.  Is probability enough to go on? 

Then there are the things that could be called a focus, but are rather soft signs.  Is a runny nose a focus?  If so, how high is the temperature allowed to be?  What about vomiting and diarrhoea?  Is that a focus in its own right?  You could throw that question out to an audience of primary and secondary care clinicians and I could guarantee that the conversation (if it continued in a way that could be called that) would go on for quite some time.  The outcome would almost certainly be that many would agree to disagree.

If you ask me, the answer depends entirely on the circumstances because the focus of infection is not nearly so important as the global assessment and the specifics of the presentation.  If a child presents early in an illness, is relatively well and has just got a runny nose, then that might be enough to go on.  Good symptom management and careful safety netting are probably the most important things in these cases.

Example 1
A 3 year old has a temperature of 38.2 at home.  They have a runny nose and a cough but no other symptoms.  They have no convincing focus of infection in their throat or ears.  Chest is clear and there is no respiratory distress.  Heart and respiratory rate are normal.  During the consultation, they are running around and playing with the toys.

Example 2
A 3 year old has had a temperature of 38 to 39 on and off for three days.  They have a runny nose and a cough but no other symptoms.  They have no convincing focus of infection in their throat or ears.  Chest is clear and there is no respiratory distress.  Heart and respiratory rate are normal.  They are alert but neither cheerful nor very active.  They have just returned from a three week trip to an area where malaria is endemic.

Who would like to accept the runny nose and cough as a focus in child 2?

So when do I need to find a focus?  Here are a few examples of circumstances in which I would want to have something that is fairly definitive:

My two top tips for finding a focus are:

  1. Repeat the ENT examination unless you have already had really good views of tympanic membranes and pharynx
  2. Check a clean catch urine sample

When deciding about how hard to look and how invasive the search should be, don't start at the beginning, start at the end.  The child in front of you and the clinical scenario determine what the hunt will involve.

Edward Snelson
Variable Venator

Thursday, 4 August 2016

What makes a GP a specialist? The Primary Care Super Power and why GPs are gods of child health

Three Tests That You Probably Don’t Need to do for Children in Primary Care

A couple of times recently, I have referred children urgently to their GP.  To some people, it might seem an odd thing for a Consultant in Paediatric Emergency Medicine to do.  Those people have not yet worked out what general practice excels in. 

Patients often attend the Emergency Department for a second opinion soon after seeing their GP.  This may be driven by the belief that the hospital doctors are specialists, while GPs are not.  Of course this is wrong.  GPs are specialists and generalists at the same time.  To be a specialist, you need to understand a topic or achieve a level of skill above that possessed by you colleagues in other branches of medicine.  Although General Practice’s greatest challenge is to know enough about everything (and that is enough of a feat), this is not the skill that makes a primary care clinician special.  Their ultimate skill is harm avoidance.

Having worked on both sides of the Primary-Secondary Care divide, I see how easy it is to treat and test, and test and treat.  GPs have an incredible ability to know what to do without tests and to do as much nothing as is appropriate.  In paediatrics, this makes GPs no less than gods of child health.

Children should not have tests done on them to reassure parents or provide thinking time for clinicians.  Tests in children should always be part of a coherent question.  We are making decisions on their behalf, so we owe it to them to avoid unnecessary pain, distress and anxiety.

So, as an offering to the gods, here is my list of three tests that I think are rarely indicated in children in a primary care setting.

1. Chest X-ray for children who ‘always cough’

CXRs are often done for two reasons. Firstly a normal CXR is perceived as a good way to rule out pathology.  Secondly the test may be done to reassure parents.

Unfortunately, the ruling out with CXR thing is much more adult practice.  The first question should be ‘is there a daily cough for several weeks?’ and then ‘is it getting better?’  However, in children these questions are more about deciding who to refer than to investigate in Primary care.  CXR is unlikely to be helpful in a child who has not developed symptoms that have landed them acutely at the doors of Secondary Care.  In fact, it may not even be normal in a healthy child.  As so many of these are done in a post-infective period, there are often streaks of something to be seen.  How then can we reassure the parents that all is ‘normal’?  I recommend watchful waiting for intermittent or resolving coughs, and referral for persistent and worsening coughs.

2. Full Blood Count for children who ‘always have infections’

Much of what applied in 1 applies again here.

I am going to propose a study into the sensitivity and specificity of FBCs in these children who are perceived to have a lot of infections.  I would guess that both are poor.  Again, the strength of General Practice becomes the answer.  Empirical evidence should win the day.  Is the child otherwise normal?  Are they growing well?  Do they get normal infections and then fight them off?  The answer is more likely there than in a blood test.

3. ECGs for chest pain and faints in children

Causes of chest pain and collapse that can be detected on a 12-lead ECG are relatively common in adults.  In children, chest pain is almost always non-cardiac and collapses are almost always vasovagal syncope.  Once again though, ‘abnormalities’ are commonplace on paediatric ECGs.  Usually these are due to age or habitus and should not be over interpreted.  The question, as always, is ‘does the symptom fit a benign cause?’  For vasovagal syncope, for example, were the three ‘P’s present? (Prodrome, posture and precipitant)  If there are red flags in the history, a 12 lead ECG is not reassuring since the event remains unexplained even if the ECG is normal.

I am not saying that these tests are worthless or should never be done.  They simply should not be done for the wrong reasons:

It is also important, before doing a test, to know what to do with borderline results or common ‘abnormalities’.

If in doubt, you can always call the relevant team and ask them if a test is useful or if the child will need to be referred regardless of the result.  If you don’t get a helpful answer, ignore them.  After all, you are the specialist.

I need to descend from Mount Olympus now and leave you to your excellent job of keeping children from harmful tests.  Now, where is that child I was seeing just now?  I remember now, they’re in CT…

Edward Snelson

Disclaimer - If you have a medical tricorder, you should definitely use that to do more tests.

This post was originally written for the Network Locums educational blog site.

Thursday, 21 July 2016

Do something for you today - reduce a pulled elbow

At least once a day, I like to think I have just simply fixed something.  Since I am not very good at DIY, that means finding some other way to scratch the itch.  Reducing a pulled elbow is hugely satisfying and anyone can do it if they know when and how to do so.

Pulled elbow (also called nursemaid's elbow) is not a true dislocation of the elbow but rather a subluxation of the radial head within the annular ligament of the elbow.

Based on empirical evidence, a pulled elbow hurts.  Additionally, there is often a second victim: the person who was involved in causing the pulled elbow (although there isn't always another person involved).  In fact, I was once hugged by a grateful relative after I reduced a child's pulled elbow.  What they don't know is that I already wanted to hug them for bringing me the elbow to fix.

Whatever specialty you work in, there are times when too much of what you do is intangible.  Sometimes I can see patient after patient and despite pouring my heart and soul into what I do, I don't get the feeling that I have really made anyone better.  These days are when I need a pulled elbow to shake that feeling off.  If you ever get the chance, I highly recommend doing it.  It is a fairly easy thing to do and, as I discovered recently, there are so many ways to do it.

When to attempt reduction of a pulled elbow

Before discussing technique, knowing how to do it isn't nearly as important as knowing when to do it.  There are some things that need to be considered before attempting a reduction.  Anyone can fix a pulled elbow, as long as they ask the right questions beforehand.

Is the child the right age?  There is bound to be a bell shaped curve for the age at which a child can get a pulled elbow. I would be sceptical about that diagnosis from the age of five up.

Does the mechanism fit with a pulled elbow?  Typical mechanisms include toddlers being swung around by fun uncles, toddlers being grabbed to keep them from running into the road etc.  A fall from a height is not likely to be a pulled elbow.

Are there signs that are inconsistent with a pulled elbow?  With distraction (not the anatomical kind), have a gentle feel of the elbow.  There shouldn't be any swelling.  There may be tenderness at the radial head but not in the distal humerus.  Feel all of the limb from the clavicle to the hand.  The two places that you are most likely to find point tenderness are the clavicle or the distal radius.

Often, children have had a previous episode.  If everything points towards a pulled elbow, there is no need to do an X-ray before attempting reduction.

How to reduce a pulled elbow

When I first did paediatric emergency medicine, I was taught to extend and supinate the elbow to reduce it.  That seemed to work most of the time.

Then, when I returned to work in a paediatric emergency department, I was told that flexing and pronating was better.  I have been doing it that way since then and it feels like it works more often.

 Of course the scientist in me is sceptical about the change.  Maybe something else affected  my success rate.  So what does the evidence say?  I was intrigued to find studies including other methods that I had not heard of, such as flexion with supination. (1)  I even found a Cochrane Review (2) which looked at the question.  It dodged the flexion vs extension question but concluded that pronation was probably successful more often than supination and possibly less painful.

So, I asked people on twitface which method they tend to use.

While finding it reassuring that two thirds of my colleagues were doing it 'my way', I was also interested to see that many will use a different method and that every possibility of twist and bend/ straighten is felt to be valid. 
I was pleased that nobody said anything about having to put firm pressure on the radial head.  I believe that all recommendations to do this are based in myth.  There is no logical reason why the radial head needs any guidance and I certainly don't press on the painful bit while applying my swift twist and bend.

I was also pleased that someone pointed out that if necessary, these can be left alone to resolve.  They always do, although it might take a day or two to finally slip back into place, during which time there will be discomfort.  I would still advocate reduction as success means that the resolution of pain is pretty much immediate.

Which brings me back to my original point.  How you do it is very much secondary to when you do it.  So, instead of worrying about technique, when the time is right, do something for you and fix a pulled elbow.

Edward Snelson

Disclaimer - I say that there are lots of methods, but my way is the right way.

For general principles of assessing children's injuries, follow this link.

  1. Macias CG et al, A comparison of supination/flexion to hyperpronation in the reduction of radial head subluxations, Pediatrics. 1998 Jul;102(1):e10
  2. Krul M et Al, Manipulative interventions for reducing pulled elbow in young children, Cochrane Library

Tuesday, 5 July 2016

Assessing Pain in Children - How Green Was Your Valley?

What is the best approach the assessment of pain in a child?  That is a big can of worms.  We want to understand the pain so that we can treat both the pain and the underlying cause but much of what we do comes from adult practice.  Rethinking our approach requires an understanding of what pain is to a child.  Pain is a very different thing for a child and so our approach must also be different.

Pain is an abstract thing, and the younger the child, the less abstract their thinking is. 

The internet has plenty of comical examples of things that children have written or said that are reminiscent of the story of the Emperor’s New Clothes.  In fact one of the most endearing things about children is the way that they often combine straight talking with unspeakable truths.  The ability to think abstractly and interpret what someone means (rather than what they are saying) develops as children grow.  We tend to develop what is needed for these situations based on experience of past events. To give you an example of adult thinking, I give you this excerpt, involving a word game, taken from a radio comedy with Benedict Cumberbatch and Roger Allam.  I think that this is a great example of how adults use words in bizarre ways and still manage to make sense.

Why does this word play make sense to any of us?  Years of having our minds messed with is the only answer that I can suggest.  Expressing feelings like pain relies on similar processes to that of understanding complicated jokes.

In order to account for these difficulties, some people adopt a standardised approach that allows children to choose how they express the magnitude of their pain.  I carry a card with the Wong-Baker faces (pictures of faces that go from smiley to sad)  and, if appropriate, ask the child to use the faces, words or numbers to say how bad their pain is.  My experience is that even this seemingly child friendly approach gives us the illusion that we are getting a meaningful answer because I am effectively speaking a different language.

When we are asking children about pain, how can we expect them to respond if they have not experienced that feeling before and lack the ability to describe it?  Imagine a nine year old presenting with abdominal pain.  All of the following questions are commonly asked of children in that assessment.  The responses are all real as well.  What I have taken the liberty to add is the internal response (I) that the child is having in their head.

Q. What does your pain feel like?  Is it sharp, burning, aching or colicky?
I. It feels bad.  Burning feels bad.  May be that’s the right answer. Someone called it tummy ache.  That must be it.  Aching.  If I say aching, the doctor will stop looking at me like that.
A. Aching I guess
Q. Does your pain come and go?
I. It hurts now.  It hurt yesterday. I’m not sure what the doctor means.  Why is the doctor still looking at me?
A. (Shoulder shrug)
Q. How bad is your pain? We use these numbers and faces here to help you chose an answer. (Shows Wong Baker Faces scale)
I. What is with all these questions?  Bad is bad.  My tummy hurts and it feels bad.  That’s not one of the choices on the list.  ‘Hurts more’ is there though and my tummy has definitely got worse while I’ve been sat here.
A. Points to ‘Hurts a lot more’ (6/10 on Wong Baker scale)

So what should we be doing?  I am not saying that questions or pain assessment tools are unhelpful, just that they should not be applied unthinkingly.  The trouble is that the child wants to give you an answer.  I think that sometimes they want to give an answer so much that they might give one for the sake of giving an answer. I think that there are two simple things that do work really well with children.

1. Just ask them what their pain is like.  A nice open question will tell you one of two things.  Either the child will describe their pain in a way that makes sense to them or they will make it obvious that they don’t really understand how to describe their pain.  Having no answer is better than a forced answer.  If they seem able to begin to describe their pain, you can progress to more closed questions and a scoring system perhaps.

2. Look at how they are behaving.  A significant tummy pain will usually manifest itself in some way in the child’s posture, activity or interaction.  A child who walks in and plays but says they have severe pain may be proving my point about understanding and describing pain.

Next time you see a child and want to know about their pain.  Ask them in a way that allows them to say what they want to say, in the way that they want to say it.

Edward Snelson

John Finnemore, Cabin Pressure, BBC Radio Comedy