The TPR paradox - how do I know if a child might have sepsis?

When I assess an ill child, I am primarily making a decision about whether the child has possible sepsis.  To a certain extent, everything else is detail.  The sepsis question determines which door the child leaves through.  Just like in primary care, I send the vast majority of children presenting to the ED back out the way they came, whether they have pneumonia, urinary tract infection or just a cold.  A small number of ill children are admitted, with the possibility of sepsis as the primary reason.  The question is: How do I decide which door to send each child through?  Once you answer that, I believe that you can begin to understand how to use the many guidelines and decision tools designed to help us make this choice.

In 1935, Einstein and two of his buddies published a paper detailing some problems with quantum physics theories.  In effect they were saying that their own advances had explained a lot about how physics worked, but that there were some things that they could not explain.  Specifically, when two particles went through two doors, one of them did something that didn't make sense.  You could do something to one of the particles and the other reacted even though they are not connected.  This is called the EPR paradox, after Einstein, Podolsky and Rosen.  These three were the best scientific minds in the world and yet they had a missing piece of the jigsaw so big that it called everything else into question.

I believe that we are in a similar place in medicine when it comes to recognising possible sepsis in children.  Once again we have two doors and sending children through these is not as straightforward as it should be.  We all do our best to send each child through the correct door.  There is a big piece of the jigsaw missing though and that’s got us all scratching our heads.  The missing bit is knowing how to go from considering possible sepsis to diagnosing probable sepsis without resorting to reading tea leafs or other substitutes for a valid test.  Most of the time we do our best and accept that in the absence of a good test all we have is good judgement.  The problem comes when a child dies of sepsis and that gap in the process comes under scrutiny.  I'm all for completing the puzzle but I am suspicious that we are trying to put the wrong piece into the gap.

If I asked you to create a decision tool for clinicians to move from considering sepsis to a provisional diagnosis of sepsis, what would you choose as predictors?  You could use the appearance of the child but that is difficult to quantify.  What seems far more reliable is TPR (temperature, pulse and respiration) since these can be measured.  The trouble is that the most measurable features of your assessment are the least reliable.

Before I get a rush of people saying that I think that you should ignore tachycardia and high temperature, please be clear that I don’t think that.  It is just that I think that there is a much better category of evidence and that numbers are not as reliable as we want them to be.

There are plenty of reasons to mistrust numbers.  For starters we have a lack of reliable reference ranges.  There is a good reason why no-one has started making a lot of money out of selling centile charts of paediatric heart and respiratory rates.  They don't exist.  There is not enough evidence to produce such a thing.  The variables are just too many.  Is it age that determines heart rate or your weight?  If it is weight then is it lean weight?  What is the effect of anxiety on heart rate?  How different is a normal heart rate in a resting child to that of a playing child or a screaming child?

What about those normal ranges that you have somewhere when you need to check?  Aren't they evidence based?  You could try to find out what their evidence base is but I could probably save you a lot of hassle by telling you that all the normal ranges that I know of are based on consensus, which is why they are all slightly different from each other. In the past few years, two large analyses have shown that some of the most commonly available reference ranges map poorly to population studies.  Even then, these publications acknowledge that the populations studied are never truly normal. (1,2)

However, I think that this whole issue is much simpler than all of that, because the wrong question is being asked.  The question is not, “Does this child have sepsis?”  The question is, “Can I say with confidence that this child does not have sepsis?”  When we use the rule out rather than rule in approach, everything starts to fall into place, including the value of numbers.

I said before that there is more reliable evidence than temperature and pulse.  That evidence is something that you rely on every time you assess a child and it is the thing that makes sense of the numbers for you: activity.   What we really want to know about the heart rate and capillary refill is not the absolute number but the effect that these are having.  What we need to assess is oxygen and glucose delivery to the organs and there is no better measure of this in a child than what the child can do once these get there.

There is one more variable which complicates the TPR paradox, which is the up and down nature of the illness.  You may see the child at their worst or possibly their best.  In any viral illness the likelihood is that the child will have extremes of activity making nonsense of the assessment.  Thankfully we have two saving graces here.  The first is that we can hear about what has gone before.  The second is that we are able to continue the assessment either by observing, referring or safety netting.

So let’s bring all of this together.  There are two simple elements to recognising serious infection in children.  The first is a hierarchy of evidence.  The second is a rule-in/ rule-out approach.

The hierarchy of evidence is logical.  If I see a child in a playground climbing up to go on the slide and their parent mentions that they have had a temperature, I don’t worry that they may be septic.  I do imagine that they have a significant tachycardia but this will be a result of their activity and possibly their temperature.  I see with my eyes both the activity and the vigour with which it is undertaken.  I don't need to ask any questions or measure any physiological parameters because I have all the evidence that I need.

If I was giving telephone advice and I hear that a child is sat playing on a tablet I now have some very useful information about the adequacy of their brain’s perfusion and oxygen/glucose supply.  It's not as good as what I see because I can't scrutinise what I am being told with my own experienced eye.

Finally if I measure a child’s heart rate and capillary refill, I have information but it needs to be put into context.  Was it cold outside?  Have they just been upset by something?  So the numbers are important but I need what I see and hear to make sense of them.

In any acute assessment of an unwell child this hierarchy can be combined with a rule-in/ rule-out approach to answer the question, “Am I certain that this child does not have sepsis?”

If what you see, hear and measure is all reassuring then the answer is yes, they do not have sepsis.  If what you see, hear and measure are all concerning then the answer should be no, they could well have sepsis.  If what you see, hear and measure give a mixed message then the question remains open and there are various ways to answer it.  Using the hierarchy of evidence above, I feel confident to give paracetamol and wait when a child looks well and behaves well even if they are febrile and tachycardic.  The options are always the same: discharge with safety netting advice, observe, discuss or refer.

Just like the scientists of 1935, none of us has all the answers.  None of the decision tools available is even close to perfect and all of them rely on someone at some point taking responsibility for making a decision about which door the child will go through.  Thankfully the majority of children answer the question for you.

Edward Snelson

@sailordoctor

If you liked this you might also like:

In Praise of Doing Nothing (Easter Egg – good safety-netting and saving lives)

Or How special is your patient? - (Neonates and other patients who don't follow the rules)

References:

(1) Fleming S et al, (2011). Normal ranges of heart rate and respiratory rate in children from birth to 18 years of age: a systematic review of observational studies. The Lancet, Vol 377, no 9770, 1011-1018.

(2) O'Leary F et al (2015) 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, Arch Dis Child, 100, 733-737

  

Is this really an injury or something else?

This is a magical time of year for the British paediatric emergency physician as children and young people are getting far fewer illnesses.  Instead of wall to wall snot and vomit, the paediatric waiting area is filled with injuries of all varieties.  Although I assume that obvious fractures will present directly to the Emergency Department, many injured children will also present to primary care.  This tip applies equally to both settings.  Hidden amongst all of the injured children will be a ‘something else’ from time to time.  They are particularly hard to spot but there are a few things that can help.

In most cases there is no doubt that an injury actually is the case of the pain.  If the mechanism fits, go with it.  (Well doc, he cycled off the roof.  Do you think that’s why his leg hurts?) What we are talking about here are soft presentations.  These are  the things that present as injury but are in fact the manifestation of something else:

• A hip thing (Transient synovitis, Perthe’s or Slipped Upper Femoral Epiphysis)
• Juvenile Idiopathic Arthritis (JIA)
• Infection (septic arthritis and osteomyelitis)
• Apophysitis (the most common being Osgood-Schlatter’s)
• Malignancy (e.g. Osteosarcoma)

Even excluding the odd one out in that list (transient synovitis, or irritable hip to give it its other name), these conditions comprise a surprisingly large number of injury presentations.  So in order to avoid the pitfall of allowing the presentation to frame your diagnosis, ask the following questions:

Is it the hip?

This is a deceptive question but an important one as hip problems are rarely true injuries.  Very often the child either has referred pain to the knee or, if younger, does not localise the pain at all, choosing to blame their foot or another random body part.  So for any lower limb problem without a blatant cause the hip must be assessed.  If the hip is then found to be suspect, what you do next depends on your experience and where you work.  I would suggest that any of these factors mandates urgent referral of a suspected hip problem:

• Age over six
• Fever
• Unable to weight bear on that limb

How long has the pain really been there?

In any of the chronic causes of pain the symptoms may have been present for a considerable time.  Despite this the pain is often put in the context of a football game or other event.  In many cases there was no injury as such, simply a worsening of pain after a fall or an exertion.  Any pain that was there already and was made worse by anything should be assumed to have a chronic cause.  This may be something relatively benign such as Osgood Schlatter’s disease but it may also be something more in need of early detection such as Juvenile Idiopathic Arthritis or a malignancy such as osteosarcoma or leukaemia.

Is the child unwell and is the ‘injury’ hot to touch?

Septic arthritis and osteomyelitis are thankfully both rare in children.  They are also completely devastating and rather difficult to detect.  If infection is suspected, refer and do not allow the buck to be passed back in the form of advice to do some blood tests to rule out infection.  If the onset is acute or the child is very young, inflammatory markers may not yet be raised. (1)  Juvenile idiopathic arthritis can also cause hot, swollen joints and may even cause systemic symptoms.

Is the problem bilateral?

If there are two of the same body part affected (and no good mechanism to explain this) the possibilities are limited.  Thankfully you can essentially rule out infection and tumour.  What becomes much more likely is one of the other possibilities.  Although an apophysitis is more probable if the tibial tuberosity or the Achilles tendon insertion is involved, other bilateral pains make juvenile idiopathic arthritis much more likely.

Have there been other mysterious joint aches over the past months or years?

One of the laments of the paediatric rheumatologists is that children present late with juvenile idiopathic arthritis (JIA).  Recurrent pains in children are often put down to growing pains.  While it is true that young people often get unexplained pains that are not related to any of the above conditions, it is also important to look for the signs and symptoms of JIA.  One of the most important considerations is the recurrent nature of the pain.  Severity is often difficult to assess as children and young people are surprisingly likely to under-report chronic pain.  They tend to assume that it is nothing (after all they haven’t yet learned to worry about all the serious possibilities that occur to their adult counterparts) or simply alter their activity so that the pain has little impact. 

If JIA is suspected, examine the affected joint(s) for swelling and perform a PGALS screen which will detect other joints that are affected which may not have been volunteered in the history.

In summary, most children that present with minor injuries do indeed have minor injuries, with the exception of hip pain, which is usually something unrelated to an injury.  Hip pain aside, it is easy to miss the rare causes of bone and joint pain.  Asking about the mechanism of ‘injury’ and pre-existing or recurrent symptoms may help to uncover chronic causes.  Examination of the affected part and consideration of the possibility of infection are also important if there is any possibility that the history of injury is a distraction.  Any unremitting well localised pain should raise the possibility of malignancy(2) unless another good explanation can be found.  Finally juvenile idiopathic arthritis is uncommon but needs to be actively sought as it is easy to miss.

Edward Snelson

@sailordoctor

Disclaimer:          I’m talking rubbish:  I’ve just had a peek in the waiting room and it is wall to wall snot and vomit after all…

(1)          BRITISH SOCIETY FOR CHILDREN'S ORTHOPAEDIC SURGERY The management of acute bone and joint infection in childhood - A guide to good practice

(2)          Suspected cancer (part 1—children and young adults): visual overview of updated NICE guidance  BMJ 2015; 350 doi: http://dx.doi.org/10.1136/bmj.h3036
http://www.bmj.com/content/350/bmj.h3036

Feed histories in refluxy babies

Over feeding?  Is that really a thing?

One of the questions that I asked most often is “where do I start when treating reflux in babies?”  This assumes two things.  The first assumption is that it is reflux that you are dealing with and second is that you want to treat it.  Each of those assumptions is worth articles of their own, so I may come back to those two issues at a later date.  However, if we are going to start our treatment somewhere, let’s start as always, by doing as much nothing as possible.  The place to start is by taking a feeding history.

I would like to say now that I do not like the term over-feeding as I feel it implies blame if it is heard in a critical way.  I don’t have a better term (yet) and it is commonly used so it will have to do.  Over-feeding is the phenomenon seen in many babies which involves them taking considerably more milk than they need or can keep in their stomachs.  As a result of this their stomachs are distended enough to cause them pain and are likely to have distressing regurgitation.

Why does this happen in some cases?  Because: the understanding between a baby and the person feeding them is that if the baby cries, that might be because they are hungry.  As a result, they are offered a feed.  Babies are fairly reflexive about feeding and so may suckle even when not hungry, leading to overfeeding.  Being overfull, they will find that they are not comfortable.  They need to let someone know about this unsatisfactory situation and so they cry, at which point someone may offer them a feed.  This is called the feed-cry cycle.

The NICE guideline ‘gastro-oesophagealreflux disease (GORD) in children and young people’ (NG1) acknowledges the possibility that a reduction in feeds might help in their recommendations:

In formula-fed infants with frequent regurgitation associated with marked distress, use the following stepped-care approach:

• review the feeding history, then
• reduce the feed volumes only if excessive for the infant's weight, then
• offer a trial of smaller, more frequent feeds (while maintaining an appropriate total daily amount of milk) unless the feeds are already small and frequent, then
• offer a trial of thickened formula (for example, containing rice starch, cornstarch, locust bean gum or carob bean gum). (1)

The devilment is however most definitely in the detail…

If we are going to be scientific about this we need to define our terms.  What is an excessive volume of feed?  Ooh, I know the answer to this one…  Nobody knows.  What we do have is a consensus that approximately 150ml/kg/day is a ‘normal’ amount.  The thing about norms is that they tend to have standard deviations and no one knows what that number is either.  So where does that leave you?

I have read through the detail of the full NICE NG1 guideline in the hopes of finding the answer and there is no centile chart of feed volumes, since one doesn’t exist.  Instead we are left with the responsibility of deciding for ourselves.  My approach is to take the feed history and calculate the volume of formula milk fed thus:

1. No of fluid ounces taken on average per feed x 28 equals mls of milk per feed
2. mls of milk per feed x average daily number of feeds equals daily intake in mls/day
3. Daily intake divided by weight (Kg) gives feed volume by weight in mls/Kg/day

If I believe that the child has GORD and the feed volume is quite a lot more than 150ml/kg/day then I will recommend a trial period of reducing the daily feed volume to 150ml/kg/day and make sure that no one feed is greater than 30ml/kg.  If they get better, it might be by random fluctuation or it might be my intervention.  Either way the child is better.  If they don’t get and stay better, I move on to the next intervention.

You might notice that I still haven’t given you a number that would qualify as “excessive for the infant's weight.”  Well spotted.  Please let me know if you find one that is evidence based.  In the meantime I will continue to believe that my number is correct.

Edward Snelson

Senior Spitilomancer

@sailordoctor

Disclaimer: You can't trust my number.  I came up with it by throwing three darts at a dart board.  It was a very good score though.


If you found this helpful you might also like to read:

Why I need GPs to be medical leaders (Easter egg - GORD in babies)

References:

1. NICE guideline ‘gastro-oesophagealreflux disease (GORD) in children and young people’ (NG1) 

Do I have to? (measuring oxygen saturation in bronchiolitis)

When something tells you what you already know...

I was recently contacted by a GP who wanted to know which oxygen saturation probes we use for babies in the Emergency Department where I work.  They were being proactive and trying to equip themselves to meet all the recommendations of the NICE Bronchiolitis guidelines.

[It is worth mentioning here that the understanding of the term bronchiolitis varies around the world.  In this context, it refers to a viral lower respiratory tract infection (in a child usually under the age of 12 months old) which has caused inflammation and secretory mucous plugging in the airways.  Typical features are cough, coryza, wheeze and difficulty feeding.  Bronchiolitis does not respond to inhalers or other medication.]

When I read the guideline, I was struck by a couple of things.  The first is the idea that the child with bronchiolitis would have to look seriously unwell to a General Practitioner before they decided to refer.  Now I know that unwell is a subjective term but my experience is that the vast majority of GPs have an excellent antenna for what I would call an unwell child.  If a child with bronchiolitis looks ‘seriously unwell’ and is in a GP surgery they may well need an emergency ambulance.  I think that the wording in the guideline is probably trying to recognise the fact that a child with bronchiolitis is not technically well.  The may not be well but they should look well.  If not, I would refer.

The next thing that struck me was the issue of persistently low oxygen saturations as a decider for a referral.  Measuring O2 saturations in General Practice is going to be a real challenge.  Most GPs will not have access to suitable probes.  Even if available it is often difficult to get a meaningful reading, especially when a child is snotty and angry.

Now don’t get me wrong, O2 saturations are very important in bronchiolitis.  I use them all the time to decide whether the child should have supplemental oxygen.  It seems like a good way to decide that.  As a doctor in a hospital, when I see a child with bronchiolitis I only really have four questions:

• Does this child have uncomplicated bronchiolitis?
• Does this child need feeding support?
• Does this child need supplemental oxygen?
• Does this child need resuscitation or critical care?

Back to the GP surgery, the real question is, will a baby with bronchiolitis who persistently has O2 saturations of 91% and below have none of the other features that trigger a referral for hospital inpatient assessment?  In all honesty (and as you can imagine, I am pretty keen not to make myself a target here) I think not.  I have no grade A evidence to back this up so instead I have a factual statement and an opinion:

Another question is: what is of most value in a primary care assessment of a baby with bronchiolitis?  Time is limited and best spent on identifying the features that identify the front of the problem not the back.  If respiratory distress, poor feeding and looking unwell are present before sats drop consistently, then ask those questions first.  Also ask whether this is another condition such as a cardiac defect masquerading as bronchiolitis.

With regards to the second question, I have asked a few people what they do if they can’t get a sats reading and the answer tends to be the same: look at the child.  When it comes to oxygen saturation, even in some quite acute situations it is additional rather than mandatory information.  A blue child is a blue child.  The O2 saturations are a useful number but I am not going to stand there for five minutes trying to get the probe to read properly before I do something about it.

What about the guidelines though?  We all have to follow guideline don’t we?  Of course you do.  If you have measured the sats and they are persistently below 92% in air, you should refer the child.  This assumes that the child did not otherwise need referral  and you still chose to measure sats.  The NICE guideline does not require you to measure saturations in bronchiolitis, it only requires you to act on the number if you have measured it.

Edward Snelson

@sailordoctor

Member of a society so secret even I can't remember what it is

Disclaimer: My experience is not transferable as I use a medical tricorder to measure oxygen saturations

Super-size me - Stratified safety netting

“The delivery of good medical care is to do as much nothing as possible” Law 13 of ‘The House of God’ by Samuel Shem (1)

As clinicians involved in the care of children, we have to do everything in our power to reduce unnecessary tests and treatments.  This can be perceived as inaction but those who know better recognise that there are two important interventions that are incorporated into every patient contact – observation and safety netting.  In paediatrics (including in General Practice and in Emergency Medicine) we rely on a watchful waiting approach to most childhood illness.  When that period of observation occurs in the child’s home, safety netting advice is not just an add-on, it is an intervention in its own right.

Why then do we treat is as a one-size-fits-all part of the consultation?  Why don’t we treat it with the importance that it deserves by quantifying it?  I suspect it is because we don’t know how to measure it.  So, to take this concept further we must first understand what makes up safety-netting.

I was first introduced to the concept of safety netting though the writings of Roger Neighbour.(2)  He wrote that safety netting was built around three questions:

• If I’m right, what do I expect to happen?
• How will I know if I’m wrong?
• What would I do then?

I often ask my junior colleagues what they say to parents at the point of discharge and although they may not have heard of this model, they will tend to cover all of these three aspects leading me to the conclusion that to do so is fairly intuitive.  Where it goes wrong is that it often tends to be generic when it should be specific.

Taking the idea that safety netting is an intervention in its own right I would suggest that as well as making sure that the three dimensions are all present, we need to get the scale correct.  Think of it as you would the treatment of an acute asthma attack.  The British Thoracic Society (BTS) sets out definitions for moderate, severe and lifethreatening episodes* and gives clear guidance about the drugs, doses and routes indicated in each scenario.  I believe that we should consciously be doing the same for safety netting ill children.

* Note the comparison to fast food chain sizes – instead of small, medium and large, we have regular, large and super-sized.

I’ll give you an example.  When I see an ill child and discharge them with advice I could stratify my safety-netting as follows:

Level 1 (e.g. child with temperature, coryza and is running around and playing)

"Your child has a viral illness and at the moment they are reasonably well despite this.  Some children do become more unwell during a viral illness but most will be fine if their discomfort is managed with medicines such as paracetamol (acetaminophen) and they are given adequate fluids to drink.  If they seem to be significantly unwell despite this then further advice should be sought at that stage.  Your child certainly has nothing to suggest meningitis or anything similar at the moment but here is a leaflet showing the things that would suggest such an infection.  We like all parents to have one of these for information."

Level 2 (e.g. Child who is alert, had a high temperature earlier but now looks really well)

"Your child has a viral illness and although they have been unwell with it they have responded nicely to fluids and simple medicines.  As a result there is no reason at the moment to suspect any other infection. As long as they continue to do so they could be expected to be as they are for a few more days.  Occasionally a child will go on to get a second infection on top of the viral illness so if your child looks quite unwell despite the medicines, becomes floppy, lethargic or is unable to drink you should make sure that you get your child seen again fairly urgently.  Here is a leaflet…"

Level 3 (e.g. Child who has clear signs of viral upper respiratory tract infection but no red flags symptoms.  Despite this they are at the upper end of how unwell children are with a viral URTI.)

"Your child has a viral illness and although they are unwell with it I am sure that there are no signs of other infections such as pneumonia or meningitis at the moment.  When children are unwell with viral illnesses they are more prone to getting those more serious infections though so if they become any more unwell than they are now they should be reassessed urgently.  If a child has a straightforward viral illness their discomfort will usually respond to medicines such as paracetamol and they will usually drink enough to pass urine regularly.  If your child looks quite unwell despite doing these things, becomes floppy, lethargic or is unable to drink you should make sure that you get your child reassessed urgently.  Here is a leaflet…"

Hopefully, you can imagine all three children in your head.  There is a big element of this that doesn't translate well into written word.  With so much communication being non verbal, a script is only a taste of this concept.  When I give my super-sized safety net advice, I use every non-verbal cue at my disposal to communicate the importance of what I say.  I hope that this approach to safety netting will ensure that the children most at risk of secondary infections have had the level of illness taken into account and thus receive the appropriate level of the intervention.  This might address one of the common pitfalls of safety-netting which is that parents sometimes come away with the impression that the doctor thought that nothing was wrong and so were reluctant to seek further assessment when the situation changed. (3,4)

So, next time you are safety netting a child at the end of an encounter, think of it as an intervention and decide on whether it should be a small, a medium or a large one.

Edward Snelson

@sailordoctor

Available to crew any good sized Mediterranean yacht

1. Samuel Shem. The House of God. 1979. ISBN 0-440-13368-8.
2. Roger Neighbour. The Inner Consultation. 2^nd edition 2004 ISBN 10: 1857756797
3. Safety netting in healthcare settings: what it means, andfor whom? Arch Dis Child Educ Pract Ed 2014;99:48-53doi:10.1136/archdischild-2012-303056
4. The safety netting behaviour of first contact clinicians: aqualitative study C. Jones et al, BMC Family Practice open access

More?!? The Salbutamol Paradox

Dosing in children is quite frankly a nightmare.  While formularies such as the BNFc are excellent and easy to follow, there are always pitfalls.  There are maximum doses and there are age related doses, weight related doses and doses that are the same at any age or weight.

Despite all the potential to get it wrong, I am pleased to report that with very few exceptions, the children presenting to the Paediatric Emergency Department where I work are prescribed the correct doses of their medicines.  This is less often the case for inhalers.  It is not uncommon for me to send a 2 year old child home with instructions to continue salbutamol (via a spacer of course) four puffs four hourly and then have another health care professional advise the parent that this is too large a dose.  If the next healthcare professional that they see applies the 'smaller children need smaller doses' principle, the parent may be advised to reduce the amount of bronchodilators to two or even one puff every four hours.

I can see the logic there.  Why would you give more puffs of inhaler to a 2 year old than a 20 year old?  Inhaled bronchodilators are a perfect example of why therapeutics in children is not governed by one or two simple principles.  In the case of treating wheeze in children it is not the size of the child or the age of the age of the child.  Once more we must turn to physics for the answer.

Delivery of the bronchodilator to the airways of the lung works best when you have good inspiration, without turbulence, through open tubes.  In a two year old, you have none of these things.  Crying looks as though it should do the job but studies have shown this to be wrong.  Aerosol deposition during crying is poor.  Even if the child is complying, they are still a victim of physics.  The flow through any tube is inversely proportional to the diameter to the power four.  This means that if the wheeze has halved the diameter of a bronchus, one sixteenth of the air will get through.  If there is turbulence of that air flow then the flow is at least halved again.  So, assuming mucous is rattling around, it doesn't take much bronchospasm to reduce the air getting to your alveoli substantially.  When you are two years old, your trachea is about 6-7mm internal diameter and your bronchi even smaller, so any reduction from bronchospasma and mucous is going to have a huge impact.

Suddenly four puffs doesn’t seem like a lot to give.  I wonder if we studied the salbutamol paradox properly if we would find that there is an argument for age banding salbutamol reliever puffs so that we give even more to the under 5 year olds as a standard reliever dose.

Edward Snelson

Using Real Science to save small lives

@sailordoctor

Disclaimer:   None of the children in medical research have ever consented to being a point mass in a vacuum. 

The Salbutamol Paradox is based on the ladder paradox, a physics thought experiment that involves getting something that seems too big into what appears to be too small a space.  Just like the ladder paradox, the salbutamol needed for a child's wheeze goes up substantially as the pace of the clinical scenario increases.

What was your question? (Easter egg - tests for bruising in children)

Fairly often, when a junior colleague is talking to me about a case I find myself asking, “What is your question?”  Sometimes the question comes at the end and sometimes not at all.  The thing is, I would prefer to have the question first and the details of the case second.  That helps me to understand everything that I am being told and it allows me to ask pertinent questions so that I can give useful advice.  I like it when people make things simple for me.

I realise however that this assumes that the person knows what their question is.  They might not.  Now this might seem like a bad thing but I have come to realise that it is not.  When someone comes to me without a clear idea of what is going on it means is that they have chosen me as a way of figuring out what their question is.  That is perfect.

What would be worse would be to do a test of some kind.  It might feel like this will add information, buy time, and clarify the question but it won’t.  If you don’t have a good idea of what the answer is before you do a test then you need to make sure that you know what your question is. 

Why is it particularly important to avoid unnecessary tests in paediatrics?  For two reasons:

• Investigations in children should not be done lightly.  They have a tendency to cause anxiety, pain or involve radiation.  Children rarely consent to having investigations so we have an obligation to avoid tests unless they are really needed.
• Most diagnoses in paediatrics can be made clinically and, if necessary, confirmed by an investigation.  It is unusual to use an investigation to look for a problem rather than to confirm it.  (The most significant exception to this is in testing urine in pre-school children.)

In most cases, one of two things is needed instead of tests:

• A more detailed history and examination
• Phone a friend

This brings me back to the discussions with my junior colleagues at work.  Discussing a case with a colleague is a superb way of clarifying your thoughts.  In many cases, the person who comes to me for advice has worked out what they want to in the process of discussing the case.  Sometimes I get phone calls from GPs who, half way through, decide they don’t need me any more.  If you work in primary or secondary care, this is the way to investigate a case, whether you know what your question is or not.

I was at the Trent Regional Paediatric Society yesterday and talking to Dr Suri from Rotherham who I know to be a very busy man.  Despite being so busy his genuine wish was that he was called more often for advice from his colleagues in primary care (and from the Emergency Department, I presume).  I realise that there is often little time to deal with a hospital switchboard but I would say that it should take less time than filling out a form for a test and later working out what to do with the result.

A good example of this effect of tests bringing more uncertainty is the child with bruises.  If you do a clotting screen I bet you will get one of the many results reported as being just outside the normal range.  Is that significant?  I don’t know.  What was the question?  If the question was “does this child have Haemophilia?” then the tests for that are complex and usually only done by a haematologist.  If the question was “can I rule out a clotting problem?” then even a normal clotting screen doesn't fully do that.

What is more likely to answer the question is a history that includes family history of bleeding disorders, excessive bleeding such as during dental procedures and cuts that never stopped bleeding.  An examination looking for lymphadenopathy, hepatosplenomegaly, joint problems, bruises in unusual places and petechiae anywhere is indicated.  In most cases I will not need to go ahead and do any test.  If I do want a test I might get a full blood count.  In that case I know what my question is: does this patient have thrombocytopaenia (e.g. ITP)?  A clotting screen will not answer that question so I don’t add it on just because I am taking blood.   The bottom line is that a clotting screen is not a good way to rule in or rule out clotting disorders in well children.  If in doubt I phone a friend.

What is certainly true is that a test might confuse the situation but discussing the case with someone who wants to help never should, assuming that they are experienced and helpful.  So, if you find yourself wanting the answer to a question or even unsure what your question is, phone a friend.  That could be a colleague where you work.  Alternatively, and if you can get hold of us easily, I hope that you will find your consultant colleagues in secondary care better value than the test you were wondering if you should do.   Another clinician willing to discuss the case is so much better than a test.  Why?  Well you can question a colleague; you can get their experience in addition to your own; they will bring new perspectives.  You can even disagree with them.  I tried arguing with a test result once.  It didn't work.

What I have learned from all this is to stop asking my colleagues at work, “What is your question?” and instead to enquire if the person has a question.  If not, that’s great.  Now I know that we are figuring out what the question is together.

Edward Snelson
@sailordoctor

Disclaimer:  I may occasionally forget all this and ask you what your question is.  I am probably tired.  Please make allowances.

Antibiotics - why I almost never prescribe them

Recently, during a session where I was teaching a large group of primary care nurse practitioners, one of the students interrupted and asked, "So, do you just never prescribe antibiotics?"  This was on about the third face to face day of the Core Principles module of the Paediatrics in Primary Care Diploma at Sheffield Hallam University.

When it comes to the issue of prescribing antibiotics in the various clinical scenarios we discuss on the course, I bring a fairly non-interventional approach.  My rationale for this is not however based on the reasons that I was taught when I was a medical student or even a GP trainee.  My avoidance of antibiotics comes from the simple realisation that they cause so many problems and are very rarely the solution to the presenting scenario.

This week I was asked to provide a guest blog for Johnathan Laird who has a site which gives practical advice about therapeutics in general.  Without hesitation I submitted my 10 reasons to avoid antibiotics in children.  None of the ten reasons are to do with resistance or oral thrush.  Here are two of the reasons:

Although it is probably my most strongly worded piece, I would like to add that I have without a doubt prescribed antibiotics that were not needed and that caused many of the problems listed.  All that I am trying to do is to be clear about why we should avoid antibiotics.  I do realise that a 100% appropriate prescribing rate is a nonsense.

So in answer to my student, I do prescribe antibiotics about three times every month.  Once for a pneumonia where the child is well enough to be treated at home, once for a urinary tract infection and once for a soft indication such as a throat or ear infection.  For the pneumonia and UTI the denominator is one, whereas for ears and throats the denominator is about fifty.  So do I just never prescribe antibiotics?  Not never but certainly with a high threshold and that threshold exists for ten good reasons.

Edward Snelson
Winner of the Connecticut State Science Fair
@sailordoctor

Disclaimer:  If my children so much as sneeze I give them broad spectrum antibiotics.  Any self respecting doctor does the same for their children.

I learned a new word today... (Easter eggs - 'Constipation' in babies and things you might not know about lactulose)

Why I have stopped using lactulose to treat babies

This month’s Archive of Disease in Childhood published an interesting paper on defecation patterns in infants. (1)  The most interesting thing for me was that I learned a new word: dyschezia.  The definition of dyschezia is difficulty with defaecation.  While it might seem like a superfluous word to those of us who use terms like constipation and painful, in the context of this article it has an important place in medical terminology because it makes a valuable distinction.

It has long bothered me that babies are referred to as being constipated.  Certainly they might go for days without passing stools and when they finally do they often do their best tomato impression.  While constipation is not the wrong word for what babies go through, it creates the impression that there is significant overlap with the constipation that is so common among older children and this is just not the case.

So what is happening to babies?  The truth is that we just don’t know.   Babies seem to be born with a tendency for their gastrointestinal tract to cause all sorts of alarming symptoms.  We use diagnoses such as colic and posseting in an attempt to give labels to things that seem to be normal phenomena in babies.  These problems are self-limiting however and are probably a feature of a GI tract that is 'learning' how to function effectively.  The trouble with each of these is that they have significant counterparts made up of a list of less common but very significant medical problems. 

Every baby who presents with symptoms that could be due to abdominal pathology should be carefully assessed to exclude such problems including urinary tract infection and surgical problems.  The full list of possibilities is much longer of course but the major clues that the baby does not have these is that they should be alert but settled, thriving and hydrated, afebrile and have no alarming signs or symptoms.

So if we are left with a baby which is not opening its bowels, straining at stool and intermittently getting upset, what do we do?  One thing that I am quite convinced of is that lactulose is not the best medicine for babies no matter what the problem. 

This brings me back my new word: dyschezia.  When babies fail to pass stools, or they strain and show signs of discomfort, they don’t have constipation in the way that a six year old has constipation.  The baby has a gut that is doing something but ineffectively while the six year olds guts are just not doing the thing at all.  “That’s fine,” you may say. “Lactulose is a stool softener so it will help the baby pass stool in this way.”  That’s what I used to believe too until a helpful pharmacist told me about how lactulose really works.  Lactulose does have an osmotic effect but it is also an irritant because when metabolised by the gut bacteria the result is chemicals such as acetic acid, lactic acid and formic acid.

So if a baby is failing to open its bowels because it’s a baby then I prefer not to use lactulose.  If I think that the problem is that the baby has guts that are trying, then driving them harder seems unfair.  I like to think about what we advise parents about how sensitive baby skin is.  How much more sensitive will their gut lining be?

What does work?    If anything is going to work, a glycerine suppository could be tried and in my experience is often successful.  More often the answer is time.  Essentially dyschezia is a common and transient phenomenon which will eventually resolve and is not a risk factor for constipation later in childhood. (1)  As is often the way in paediatrics, time spent looking for the correct diagnosis and explaining things properly to the parents is time well spent.

Finally, I think that dychezia is a terrible word, right up there with erythema toxicum on the list of things that I will never say to parents that their child has.  Can anyone out there suggest a better one?

Edward Snelson

Junior gunner, Crimson Permanent Assurance

@sailordoctor

If you found this helpful you might also like:

Feed histories in refluxy babies

Non-specific abdominal pain - why I haven't made that diagnosis for quite some time

References:

(1) Defecation patterns in infants: a prospective cohort study (Kramer et Al, Arch Dis Child, doi:10.1136/archdischild-2014-307448)

http://adc.bmj.com/content/early/2014/12/24/archdischild-2014-307448.abstract

Disclaimer:  I don’t know what babies are thinking either.

Schrodinger’s Safeguarding Case

Whether you've been practising medicine for 30 minutes or 30 years, dealing with the issue of safeguarding is one of the biggest challenges for any of us.  We are told that there are several must do’s such as:

Wait a minute...   I know the list goes on but those first two are quite enough to deal with before we process any more.  What those two statements mean in practice is that the minute I've thought of a way that this could be a safeguarding issue, I am doing mental gymnastics trying to figure out the following things: 

If this comes easily to you then you have my admiration.   For the mortals among us it is so challenging that at some point most of us have wished that there was no concern or that we didn't have to be the one that brought it up.  You have to be careful though, because when you find yourself wishing for these things you might just do something to make them happen.  It is within your power to explain the concern away.  It is possible to refer to someone else who will take your concern further without telling the parents.  Neither of these are good ‘ways out’.

The problem is that we often see the way forward as a choice or a judgement on the situation.  This choice forces us to feel as though we are choosing sides which is intuitively at odds with our instinct to be on the side of the parents.

There is a solution that I believe does work: Schrodinger’s safeguarding.   [If you don’t know about Schrodinger’s cat (a mixture of quantum physics and animal abuse that makes sense in a strange way) then don’t worry.]  The principle that I want you to get you head around is this:

In this way you can overcome all the barriers to dealing with the problem.

Because you treat the concern as fully real:

• You will act in the best interest of the child.  You will explore the concern until satisfied.
• You will involve all the right people.
• You will ask all the right questions and document things in far more detail than you would normally.
• You will tell the parents that you have a concern because you can’t do the first three things adequately without them noticing that something is going on.

Because you treat the concern as fully false you will come across differently and the parents will sense your open-mindedness:

• You will come across as non-judgemental.   You will be able to be matter of fact about the need for the safeguarding concern to be raised and answered and they will sense that you have not judged them.
• You will keep the health of the child as a top priority.  The parents will have come with their own agenda and you will remember to address that just as you would have normally.  This also helps parents to see that you have not de-humanised them.

So next time you have a safeguarding concern, do put it back in the box.  Not a Pandora’s box but a Schrodinger’s box.  You're not making a judgement but you do need to do both of your jobs.

Edward Snelson

@sailordoctor

Disclaimer:  Damn it Jim, I'm a doctor not a quantum physicist.