00:00
Let's switch now to perhaps slightly deeper infection which is Croup. This is a viral infection
of the larynx. It happens in kids. In adults, this is laryngitis. In kids, this is croup. It typically
affects kids between 3 months and 3 years of age and usually they have upper respiratory infections,
runny nose, congestion, cough. So, classically we're taught that this is caused by parainfluenza
virus. That's the answer on your test. But realistically this can be any virus at all. It can be
paraflu, it can be flu, it can be RSV, it can be adeno, it might be enterovirus, rarely human
metapneumovirus, usually that's bronchiolitis but it could be and it certainly could even be
coronavirus. It doesn't really matter what the virus is. What's more important is that they're
sick and they need our help. So, typically these patients will present with fever with a barking
cough, people describe it as a seal if you ever heard a seal bark, that's sort of what it sounds
like. They almost always will have a hoarse voice. This is the kind of question that's a good
clinical pearl. You should ask that mom "Does your child sound like they're crying as like it
normally is or does it sound hoarse?" and frequently they'll _____ "Oh yeah it
sounds much different and that's a clue it's probably croup. They may have difficulty swallowing,
they may have drooling because they don't want to swallow their saliva and they may complain
of throat pain if they're old enough to tell you about that. So there is this score called the
Westley croup score which is out there and sometimes it shows up on tests. Realistically, we almost
never used this score so I'm not going to go through the details of the score, it's there if you
want to look at it. What's key is that these patients present with stridor and stridor is the
thing that worries us most. Oftentimes they'll present with stridor waking up at night.
02:06
Classically parents say "had a cold, put him to bed and then in the middle of the night he started
crying and when I went he was making this horrible noise while he was breathing in." Remember,
stridor is from a narrowing of the upper airway. In patients who have stridor at rest, we're
really worried about these children and we generally would like to have them in the inpatient
setting. In patients who have stridor only with severe agitation like crying, that might be okay
as long as their airway is otherwise fine. So we worry about kids with stridor at rest. When we
see a patient with croup, we want to make sure it's not another thing. For instance, "How do I
know this child doesn't have a cold and recently just got a foreign body lodged in the throat?"
There can be some clues about foreign body that are important. Examples would be "Mom says the
child was completely fine and then all of a sudden there was remarkable stridor." That would be
unusual. Very rarely this could be a mass or an airway hemangioma. It's interesting, children
with airway hemangiomas often show up with croup because they're more susceptible to it because
there's less space in that airway in the first place. In a child with recurrent croup infections,
you might worry about some airway mass or problem. Patients may have epiglottitis although as
we already discussed in the epiglottitis section of this talk that's fairly rare now. This might
be an allergic reaction. We want to listen for wheezing too and look for areas of edema like on
the lips or the tongue. If you're concerned about this being something else, the test of choice
is an anterior x-ray. What you'll see on anterior x-ray is called the Steeple sign. This is commonly
on test. The ID is from the front, that airway which you can see on this x-ray, looks a little bit
like a church steeple. Here's the church fitting right in there with the steeple pointing up.
04:04
That's your sign that that what's the problem is. So let's talk about the management of croup.
04:09
First off, we have classically taught people that if it's at home and it's relatively mild, humidity
or cold air might work. We tell the families you can go in the bathroom and steam it up and put
the child in there or you can take the child outside where it's cold because this usually happens
in the winter and the cold will help shrink the swelling in their throats. Maybe this works,
probably it doesn't. There was 1 study from Canada where they showed the humidity was not
beneficial. So why do this seem to work? Well they seem to work, remember a child that's crying
has a long exhilational phase and a very quick inhalation. So what happens is as that child is
breathing in quickly, the stridor is worse. Once they stop crying, the stridor gets better. So if
you can imagine, child wakes up in the middle of the night, starts crying, parents hear the
weird stridors, noises, run in, take the child, bring the child to the bathroom, wait for the
bathroom to steam up. By now the child has stopped crying. The humidity maybe that helped the
crying, that's a stridor but maybe it was just that the crying stopped. In the emergent setting
though, we have a few things we can do. The first is we will give a dose of dexamethasone. Some
people like to use prednisone but most of us preferred dexamethasone. Why do we care? Because
dexamethasone has a much longer half life, tends to last about 3 days. So you can give 1 dose
of dexamethasone rather than 3 doses of prednisone and a prescription that the mom has to
take home and try and wrestle to get their child to take what is the somewhat nasty tasting drug
once or twice a day. Dexamethasone, you give it once you're done, you can give it through orally
or you can give it through an injection. Also, because the dexamethasone takes a few hours to
kick in, in an emergent setting we can give racemic epinephrine. We give that nebulized. The
child is to breathe in this treatment. That racemic epinephrine causes alpha constriction and a
constriction of the blood vessels that are providing the edema in the throat. In other words, it
acutely reduces the edema. One thing you have to watch for though is that the racemic epinephrine
is relatively short acting. It wears off within an hour or 2. So you have to watch that child
to make sure they don't get worse again. It would be crime to give a child racemic epinephrine
and then say "Yup, okay you're good to go" and then have them be at home when the child gets
worse again. So what we'll typically do is give a dose of racemic epi and give a dose of
dexamethasone and watch for a period of time. If the child needs another treatment, often
they're admitted to the hospital but what usually happens is the dexamethasone has kicked in
by the time the racemic epinephrine has worn off and the child should be good to go. Some
people like to give another dose of dex the next day. There's no evidence to say that's a good
or a bad thing to do. Generally, we will discharge those patients who are admitted once they're
without stridor for a 3 to 4-hour period. So, once they're no longer requiring epi to keep going
they should be okay to go home. What's key is we never send these children home who have worked
up breathing or who have stridor at rest. So that's my summary of the major common infections
of the upper airway. Thanks for your time.