Now that children have returned to school you may have
notice something new in your consulting room: the smell of stale vomit. I think that I have a fairly protected
professional life but puke is not one of those things that I mention when
extolling the virtues of my (eventually) chosen career. As winter approaches, the number of children
with viral gastritis and gastroenteritis will go up and up until one day before
Christmas, I will have a loved one ask me to shower before supper so that I can
be in polite company.
Perhaps there is one good thing to come out of all this
though. I think that all these vomiting children have taught me something
that not everyone else knows: For the child with viral vomiting who will not drink, paracetamol is an accidental anti-emetic. (I am also
fairly sure that there is no medical evidence for it, having done a literature
search.)
Anti-emetics are traditionally avoided in viral vomiting due to the possibility of side effects which might complicate what should be a self-limiting illness. In the UK, most children with viral gastritis/ gastroenteritis do not become significantly unwell. However it is unpleasant and occasionally causes a child to become severely unwell.
I know that I can’t prove my belief but I can tell you this: I
frequently see children who seem
unwilling to drink and incapable of appropriate onwards gastric peristalsis
(AOGP, as well as a new acronym, happens to be the sound made just before an
almighty puke). Parents bring their children in the hope that we will help. These children seem
beyond simple measures and yet almost without fail, an hour after a dose of
paracetamol they are drinking, soon to be followed by appropriate discharge.
Why haven’t they been give paracetamol already? That’s easy.
It is counter-intuitive to give slimy medicine to a child who vomits
every few minutes. It stand to reason
that it will come straight back or precipitate a puke. The child may not be febrile and even if they
are it seems a waste of good medicine.
When I sit down to write these posts, I enjoy the fact that
FOAMed allows the writer to be free of the normal constraints of traditional
forms of publications. I am keen,
however to make sure that I don’t write anything that is dangerous or
wrong. As mentioned above, I really did do a literature search on this. You may have noticed that I never
sport a serious disclaimer. This is for
two reasons. Firstly, a disclaimer is no
defence against wrongness. Secondly a
lack of a disclaimer is no excuse for you to go and jump off a bridge just
because I said so. We have an
understanding, you and I. I will make
this as good as I can make it and you will be professional, question my advice
and apply what you get from it in the context of everything else that you know
about clinical medicine. That said,
paracetamol really is an anti-emetic when a child has viral gastritis.
In the absence of a randomised controlled trail (that will probably never be done) one needs a plausible explanation for one's claim. It works like this: When you feel unwell and have abdominal pain you do not want to
drink. Pain and malaise are both emetic
in their own right. Paracetamol reduces
pain and feelings of malaise, helping a child to vomit less and drink more.
There are two caveats with this. Firstly, I would be against giving repeated
doses paracetamol too readily to a child who is dehydrated. Secondly, remember that many paracetamol
suspensions contain sugar substitutes which are hyper-osmolar. Sugar is preferable in vomiting children
since they need to energy and don’t need the diarrhoea that can be made worse
by sugar free suspensions.
I know that just because it makes sense doesn't mean it is
true, nor does an observed association prove causation. (1) In this case I have been convinced of an
association because it seems to work and it makes sense. If that’s good enough for you, then
great. There are plenty more like this
to come in future posts.
Edward Snelson
Statistical Sceptic when it suits me
@sailordoctor
Disclaimer: Were you even paying attention? I covered this.
(1)
Predictive factors, Archimedes - Towards evidence based medicine for paediatricians, Bob Phillips, Arch Dis Child 2015;100:892doi:10.1136/archdischild-2015-309409
