Showing posts with label Croup. Show all posts
Showing posts with label Croup. Show all posts

Wednesday, 12 December 2018

Making the Right Judgement - a comprehensive 3D model for deciding what to do with each child with a respiratory presentation

In the previous post, I covered how best to make a diagnosis of lower respiratory tract infection (LRTI).  Anyone who has the pleasure of working with acutely ill children knows, the diagnosis is only a small part of what we do.  A big part of what we do is making that all important decision - home or hospital?

This decision is usually made up of several elements.  What is interesting is that the same principles can be applied to all of the major respiratory problems that we see, namely:
  • Bronchiolitis
  • Viral Wheeze
  • Asthma
  • Croup
  • Pneumonia (LRTI)
Once one of these diagnoses has been made, the decision about whether to admit or manage at home is a huge one.  On the one hand, we don't want to admit children to hospital unnecessarily.  Apart from the inconvenience and stress to the family, there is a significant risk of adding insult to injury as so many children who attend hospital acquire additional infection.  On the other hand, we know that if a respiratory problem does deteriorate, it can do so quickly and catastrophically.  If there is a significant risk of a child going off, they should be somewhere that can respond appropriately.

In the majority of childhood respiratory illnesses, the treatment itself is not what requires the child to be in hospital.  It is no longer routine to have a chest X-ray and intravenous antibiotics for uncomplicated community acquired pneumonia. (1)  Many children who are admitted with pneumonia receive no investigations and are treated with oral amoxicillin and discharged when they show improvement.  Severe croup is often a waiting game.  Viral wheeze is usually treated with inhalers via spacer.  Babies with bronchiolitis are often observed while a team of expert paediatricians avoid the temptation to "try something" that research has proven to be pointless.  You get the picture.  These are the times that paediatrics is the art of masterful inactivity.  Believe me, that is harder than it sounds and is actually quite labour intensive when done properly.  The point is, they still need to be there, because these are the children who, if they got worse, would require escalation of treatment.

So if the need for hospital specific treatment isn't always the thing that determines the need for admission, what else is?  In illnesses that always need hospital treatment (e.g. Kawasaki Disease) the decision is made for you.  However in respiratory problems that can be treated in the community, the decision is mostly about risk assessment, which is never as simple as people make it sound.

Guidelines often imply that the assessment of a respiratory presentation is a simple matter of deciding severity or calculating a score.  I like an over-simplification as much as the next clinician, except when it doesn't work, which is fairly often.  Why isn't it that simple?  Because not a one dimensional assessment.  The good news is, it's not that complicated,  It's just 3D instead.

D1 - Severity

The first dimension of the assessment is to decide severity.  All acute respiratory problems, like chain coffees, come in small medium and large.  Deciding which presentation fits into mild moderate or severe is fairly intuitive and the same principles apply across the different diseases.
Severe makes the decision easy.  Severe needs to be treated in hospital for several reasons.  Severe is usually a set piece, and although severe can be terrifying, it's not usually a cause of decision fatigue.  That comes from deciding what to do with the rest of them.

In a previous post, I shared some thoughts on croup scores and severity.  You can read that via this link if it would be helpful.

Mild cases of croup, bronchiolitis, viral wheeze, asthma and LRTI are almost always best managed at home.  Almost.  Moderate cases can often go either way.

D2 - Risk factors

This means that other factors are involved in the decision.  Because we are assessing risk, we need to consider risk factors.  These, when applied to the severity of the illness literally multiply the risk of something bad happening.
As a rule, a risk factor alongside a moderate severity of respiratory problem is ore than enough to mandate admission to hospital.   That child with croup that you were thinking of sending home- I suspect that decision will be changed when you factor in the fact that they were born prematurely at 26 weeks.

What is slightly more complicated is how risk factors apply to the child with a mild presentation.  It's complicated because the presence of a risk factor does still ramp up the risk, but its a factor applied to a very small risk in the first place.  What's more, the same risk factors that apply to the presentation also apply to the risk of being in hospital.  An ex-premature baby with mild bronchiolitis could go off, but the risk is still small.  An ex-prem baby in hospital if they don't need to be is a risk all of its own.

The decision about what to do with a child who has a mild respiratory problem but also has risk factors is a difficult one.  It is a decision best made by an experienced clinician who understands the way that the particular risk factor interacts with the illness and knows the pitfalls associated with it.  If you're not sure, refer or discuss the case.  This may be a good opportunity for an experienced primary care clinician to share that decision with an experienced paediatician via a telephone consultation.

D3 - Red Flags

Finally, there are red flags.  Although independent of the apparent severity of the presentation, these features will usually mandate referral or admission.

A good example of a red flag feature would be a 4 month whose clinical examination is consistent with mild bronchiolitis.  If the accompanying adult says that the infant had an episode of suddenly becoming pale and floppy earlier that day, this should be treated as a warning sign.
Bringing those three dimensions together will give you the answer to the "home or hospital?" question.  It will also help the communication between primary and secondary care.  Referring a child with a respiratory problem, summarised as diagnosis, severity, risk factors and red flags is just showing off.  There's nothing wrong with that is there?

Edward Snelson
Dimensional Relativist
@sailordoctor

Disclaimer: I'm never sure which is worse: oversimplification or undersimplification.

References
  1. Guidelines for the management of community acquired pneumonia in children: update 2011 British Thoracic Society Community Acquired Pneumonia in Children Guideline Group


Tuesday, 23 October 2018

The Practicalities of Croup Management in the Community

This post is in response to a very specific question from a local GP. The question wasn't about recognising croup or even about the best evidence based treatment.  Recognising croup is fairly straightforward. There is pretty much consensus on the best management of croup. The question was about the practicalities.

The evidence for the ideal management of croup has given us a fairly straightforward and reasonably robust answer: a single 0.15mg/kg dose of oral dexamethasone.  Sounds simple doesn't it?  The difficulty is that a single dose is actually quite problematic from a pharmacy point of view. As a result the decision isn't always about the best available evidence.  It might also be about the best available medication and formulation.  To determine the answer to this question, we need to go back a couple of steps.

Croup is a clinical presentation involving barking cough, with or without stridor and respiratory distress.  This usually occurs in a relatively well child, though they will have the symptoms of a viral upper respiratory tract infection.  Like so many presentations in childhood, the underlying cause is a viral illness but the problem is due to the effect or response to the virus.  In the case of croup, that effect is upper airway inflammation and swelling.

When should croup be treated?
Croup is usually classified into mild, moderate or severe.  This can be done with or without a croup score.  While it is a minor oversimplification of what happens next, the likelihood is that severe croup will be treated with steroids and often admitted to hospital while moderate croup will usually be treated with steroids and discharged home after a period of observation.

It is the management of mild croup which often generates the most discussion.  The first question is whether it should be treated at all.  There is evidence that treating mild croup with corticosteroids (1) reduces symptoms.  There is the suggestion that it is safer to treat mild croup in that there is a reduction in time spent in hospital and reduced readmission rate for those that are treated.  However there is no specific evidence that not treating mild croup leads to an increased risk of severe or life threatening croup.  This leads some clinicians to the conclusion that if a child has a barking cough but no stridor or respiratory distress, they prefer to provide safety-netting advice and reassess if the child develops new signs.

How should croup be treated?
There is also evidence regarding the most effective steroid treatment for croup in children.  Oral dexamethasone outperforms oral prednisolone.  Both oral treatments outperform nebulised budesonide.  The suspicion is that dexamethasone outperforms prednisolone because it is better tolerated.  It's difficult for a medication to be effective if it's just been puked onto the floor.


If that's all so well evidence based, what's the problem?  Lets's get on with giving them all dexamethasone 0.15mg/kg. The problem with this is that is that dexamethasone liquid has done itself out of a job.

Dexamethasone is given as a single dose in the vast majority of cases.  The evidence shows that this works well, quickly (2) and with an effect which is sustained over several days.  It is quite potent, so small doses are effective.  These factors, combined with an unpredictable demand and a relatively short shelf life make dexamethasone liquid something that doesn't make business sense for pharmacies to stock.

I recently asked the twitter community about what they had available and while many did have dexamethasone liquid, it certainly wasn't routinely available.  The question also sparked a smattering of stories from people who had been sent from place to place looking for one that had some dexamethasone available.


This then presents a dilemma for the clinician in the community.  Do you prescribe the best tolerated and most effective treatment and take the risk that it will be unavailable?  Do you prescribe an alternative (soluble prednisolone) that is known to be slightly less effective and less well tolerated on the grounds that a medication can only be effective if it's actually been given?

There is also an opportunity to be proactive about the issue.  You could get a member of your team to contact the local pharmacies and ask if any of them do stock liquid dexamethasone.  If not, perhaps one would in which case they would be where you sent your children with croup for their treatment.

On a larger scale, primary care groups (e.g. Clinical commissioning groups in the UK) could coordinate something so that each locality has a pharmacy that stocks liquid dexamethasone.

Another way of looking at it is that there is a vicious cycle to break.  Because dexamethasone is not always available, not everyone provides it.  Because it is not prescribed often enough, it is not always stocked by pharmacists.  More prescribing of dexamethasone should make it more likely that dexamethasone will be stocked.

It is possible that liquid dexamethasone will become a more commonly prescribed medication since it has recently been suggested that it is as effective as prednisolone for childhood wheeze. (3)

What about age banding and using soluble dexamethasone?

Dexamethasone has a large therapeutic window.  The current recommended dose of 0.15mg/kg is a quarter of the dose of 0.6mg/kg which was previously the most often used dose.

This is good because age banding doses is very difficult.  A four year old can be anything from 13-22kg based on the 9th-91st centiles of the WHO growth charts.  Knowing the age is therefore nowhere near as good as having an actual weight.  Obtaining a child's weight does not require any special equipment.  If a child will not stand on a set of scales, simply weigh an adult carrying the child and without holding the child.  The difference is the child's weight.

If using Using the 9th-91st weight centiles and aiming for a dose of 0.15-0.3mg/kg gives the following results:






















The ideal is definitely to have a weight and to have a liquid suspension available that would allow the precise dose of 0.15mg/kg to be given.  However, when thinking about a plan B, it seems a shame to go to Prednisolone which is known to be less effective, has more side effects and can only be given in aliquots of 5mg.  Why not do the same with dexamethasone, even if it does mean that the dose may be over in some cases?  Again, the therapeutic window of dexamethasone allows this to be possible.

Although liquid dexamethasone is not always on the shelves of the local pharmacy, it probably should be and possibly would be if it was more often used and the pharmacist knew that the bottle would get used.

Edward Snelson
Pharmacoeconomist of the year 2020
@sailordoctor

Disclaimer - If treatments are better but do not make sense financially, children should have to pay for that themselves.  If necessary, there are some coal mines near me that could be reopened, giving the children an opportunity to earn the money to pay for all the wasted dexamethasone that they are responsible for.


References

Saturday, 9 April 2016

The Best Medicine

We all want to give the best medicine. If you are not part of that ideology, please stop reading. This is not for you.

Prescribing for children is tricky.  Sometimes dosing is about weight, sometimes age and sometimes it's not that simple such as when giving bronchodilators.  The choice of treatment is also difficult. I try to practice evidence based medicine but there is often a lack of good quality research on which to base my decisions.

In the brave new world of guideline driven medicine, there is one factor that I don't often consider and that's a shame because it can make all the difference.  That factor is the acceptability of the treatment to the child.

In our desire to make a child better (or at least feel better) it may be wise to consider what the child wants. I know, that's crazy talk.  But the best medicine may just be the one that the child will take.


Let's talk about a few examples.

What is the best corticosteroid for treating croup?

I recently ran through the management of croup.  In that I addressed a question that I am often asked by my GP colleagues: "Should we be giving dexamethasone or prednisolone?"  The evidence comes down gently in the favour of dexamethasone. However,  prednisolone is often cheaper and more readily available.  

But what would the child choose?  I have prescribed each of these steroids enough times that I've got a strong suspicion that a consumer survey would say dexamethasone is the customer's favourite.  This is based on the number of pens I have worn out writing that prednisolone can be re-administered since the first dose is now fluorescent decoration on a parent's clothes.  This is a lot easier to sort out while the child is sat near me in the ED.  It's less easy to resolve if they've picked up their medicine from a pharmacy and are at home when they vomit back their steroid.

I don't have the facts on how many children spit out or vomit back prednisolone versus dexamethasone.  It would be good to know so that I could offer more than a belief when someone asks the dex/ pred question.  In the absence of hard facts, I will continue to point to the dex bottle and mouth, "This one!" in a way that allows plausible deniability.

What is the best oral antibiotic for bacterial tonsillitis in children?

I recently read with interest an article in the Archives of Disease in Childhood about another treatment choice that would affect even more children.  This article had the bravery to question the well established practice of giving ten days of phenoxymethylpenicillin  to children with suspected or proven streptococcal tonsillitis.  Apparently the old thing about a high proportion of cases of Epstein-Barr virus (EBV) infection having florid rashes when prescribed amoxicillin is a myth.  Well, technically it is a misunderstanding (or mythunderstanding perhaps?) since the reaction described originally was to ampicillin.  The latest evidence is that there is no increased occurrence of rash when amoxicillin is given and EBV is present.  Can I trust no one?

The article goes on to mention (casually, as if to avoid hate mail) that since amoxicillin is better tolerated by children, perhaps we should prescribe this instead of phenoxymethylpenicillin.  Bonkers.


Now before anyone changes their practice, there is another consideration: antibiotic guardianship.  Amoxicillin has a broader spectrum of antimicrobial activity and with rising bacterial resistance we should be using broad spectrum antibiotics as infrequently as possible.  What is exciting to me is that someone has questioned our long-continued routine.  Better still, they have as good as involved the child in the discussion that should rightly follow.

Is phenoxymethypenicillin that bad?  Parents frequently tell me that the phenoxymethylpenicillin prescribed to their child has transformed them from a nice child with a febrile illness into some sort of rabid beast undergoing an exorcism.  It seems entirely reasonable therefore to ask that the writers of guidelines consider whether the evidence and stewardship of phenoxymethylpenicillin outweighs the acceptability of amoxicillin.  How many additional completed completed antibiotic courses would it take to allow amoxicillin to win in a straight fight?

I would not be me if I didn't mention the other option for the child who has a deep loathing for their antibiotic.  There are ten good reasons to make stopping the antibiotic the best way forward. There is only really one reason to change to something like amoxicillin: the child needs the antibiotic.

Edward Snelson
@sailordoctor
Medical mythologist

Disclaimer: Trust no one



References

Tuesday, 15 March 2016

Croup - proof that a number is never enough information

Croup has to be one of the easiest upper respiratory tract infection diagnoses to make.  You can literally hear the child coming.  The classical croup picture is one of a child who has a cold for a few days and then develops a cough that sounds like a seal.  Although there are differentials listed in the textbooks these can also be excluded clinically:

  • Inhaled foreign body - has not inhaled a foreign body
  • Bacterial tracheitis and epiglottis - child does not look that unwell and is able to swallow their own saliva

So, it is a simple case of, "this is croup!"  The next job is that you have to ask yourself how bad the croup is.  The good news is that there are scoring systems available.  The problem with scoring systems is that they create the impression that the game is over.  It really isn't.


If you do use a croup score, you should see it for what it is: a snapshot which attempts to quantify what you see and hear.  As is often the case, these scoring systems are developed for the purposes of research and have been adopted into clinical practice.  It is equally valid to take the signs and symptoms and qualify these into a mild, moderate or severe croup.  You might find a scoring system helpful but it is not mandatory.  Whether you use a qualitative or quantitative method, the severity is only part of the picture.

One thing that guidelines often struggle to emphasise well is the importance of the trajectory.

All three children in the figure above have a Westley croup score of 4 when seen by a clinician.

Child A was found in the morning with a stridor and significant respiratory distress. As often happens, when the parents rushed the child to be seen, child A improved and now has the tail end of a soft stridor.


Child B was coughing, had a soft stridor all night and refuses to move out of croup limbo.

Child C was not so bad when they set off to see you but has got noticeably worse in the time leading up to the consultation. The game is just beginning for child C.
The score (or your qualitative mild/ moderate/ severe assessment) and the trajectory are the most important factors. I would also consider risk factors including co-morbidities and previous life threatening episodes of croup.

That brings us to croup management-

Turbulent flow of air creates more than twice as much resistance as laminar air flow. Children who have croup will tend to position themselves and breathe optimally if left alone to do so. Distressing the child either directly or via the parent can cause sudden decompensation.


If the child is in the severe category then facial oxygen should be given followed rapidly by nebulised adrenaline (epinephrine). Doses as per your formulary but at the time of writing that is 5mg for a child 2 and up where I work.  If not already at hospital, a child with severe croup should be moved there quickly. If already in an ED then the child may need further escalation but in many cases the adrenaline will buy time and avoid the need for airway management.


For mild and moderate croup the best evidence is for systemic steroids.(1)  There is evidence that dexamethasone is more effective than prednisolone.(1) Studies have also compared different doses of dexamethasone and found that there is no difference between giving the larger dose 0.6 mg/kg and the smaller dose 0.15mg/kg.(1) I have been using the lower dose for many years but have no hesitation in repeating the dexamethasone if the child vomits afterwards and it is uncertain as to whether the first dose stayed down.


Be warned, my GP land colleagues: dexamethasone liquid can be difficult to source from community pharmacies. NICE says that "Providers of urgent care services should ensure that dexamethasone is available."(2)  This may not be within your control.  Unless you know that your patients can get it easily, prednisolone may be the pragmatic choice.


I am very aware that treating mild croup is a relatively new phenomenon. If you fear change, please take comfort in knowing that I do too. However my dislike of medicalising childhood illnesses does not extend to croup. This is for two reasons. The first is to do with the aforementioned trajectory. I don't know which mild croups are going to become moderate or severe but some will and theses children may become victims of another fact of science.

The flow of air through a tube is reduced by the reduction in diameter to the power 4. If a child with croup gets worse and their airway haves in diameter then they will only be able to shift one sixteenth of the air. If that air flow becomes turbulent then you won't need a score to tell you how bad they are. So mild croup is not a thing to dismiss. It is level one of the game of croup. Level 1 is deceptively easy but unlike most games, level 2 is much harder and level 3 completely unexpected.


Edward Snelson
@sailordoctor

Disclaimer: It's not a game.

References:

  1. Cochrane library review, Glococorticoids for croup
  2. NICE, Clinical Knowledge Summary for Croup