Now, we're going to put our stethoscopes away, for a bit,
we'll come back to them in a minute,
to demonstrate percussion of the chest.
This is an extremely useful skill first described by, Auenbrugger,
in the 1800s, where he found that,
his father had shown him that tapping on a cask of wine,
could give him a sense as to how much wine was left in the cask.
And he as a physician, learned that, you could do the same thing with a chest wall,
to discern whether or not there is fluid in the chest.
So, percussion is a very important skill,
that we'll use certainly in the abdomen and particularly here in the chest.
A few important points about percussion.
When you're percussing any organ,
you're really looking for three specific sounds:
Resonance, tympany, and dullness.
Dullness, is a very short flat low-pitched sound,
that you would hear, simply if you percuss over some muscle,
so, we can do that now.
Barely hear anything at all.
It's a very short quick sound that doesn't last very long,
because it's short.
The next sound we were listening for, is, resonance.
Resonance is the sound of a chorus of low-pitched sounds,
throughout a tissue, that is relatively hollow,
it's not a hollow viscous, it's not a drum,
but it is nonetheless airy and light
and that perfectly describes the chest, right?
So, let's take a listen to see what the sound of resonance sounds like.
You'll note that, my finger is typically for most physicians or clinicians,
you're hitting the distal segment of your middle digit,
I'm keeping my other hands off the chest
to avoid dampening down the sound,
and that's the sound that I’m reproducing,
which is the sound of resonance.
In contrast, tympany is, since that's also describes a particular drum,
in somebody's drum set, is a specific pitch
and you're typically looking for tympany,
when you percuss over a hollow viscous,
the stomach would be the most obvious example.
When you percuss over the stomach, you'll actually hear,
one pitch it's a hollow sounding sound
and it tends to have a longer duration
and it's lower in pitch depending upon the size of the viscous,
that you are percussing.
Maybe we should demonstrate that now as well.
So, this, is the sound of tympany, you can tell it's a single pitch,
it's hollow sounding and it's relatively long as well.
Normally, the chest should only have resonant sounds
and we'll talk about what the significance is,
of finding sounds other than resonance in a moment.
All right, now that we're back at the examining the chest again,
with percussion, we're going to march down
and compare one side to the other, as we engage in percussion.
And you'll note that, right around here is the transition point,
where I go from resonance to dullness,
which in this case, would be me moving from the above the diaphragm,
where I’m procrastinating the lungs,
to below the diaphragm, where presumably I’m percussing the spleen,
on the left side and on the right side I’d be percussing the liver.
So, just by doing that simple technique,
you can get a good sense of where the bottom of your lungs is located,
you can imagine that if his lungs were full of fluid
or if one side was full of fluid, we'd have asymmetry,
where that dullness would occur much earlier
on one side than on the other side.
Incidentally, for some folks who may have very small hands
or have trouble making a significant sound with their,
this is called the “Plexor” this is the “Pleximeter,”
you can actually cheat by using a, “Reflex hammer” like so.
Makes a bit more noise, if you need to, to create a louder sound.
That being said, it's been said that,
it is much easier to tell the difference between something,
rather than nothing, than to tell the difference between more and less.
And I say that because, if you hit too strongly with your hammer,
you're going to get sound that's fairly loud throughout,
even as you start going down towards below the diaphragm,
so, it's been suggested that, actually percussing very lightly,
and noting, where the sound really disappears all together,
something versus nothing,
can sometimes actually help to create a more sensitive exam.
But by all means, if you're in a loud emergency room,
then using the reflex hammer, can certainly help to accentuate that.
And now, the last part of the lung exam on the chest,
is looking for, “Tactile Fremitus.”
Fremitus describes, the normal vibrations that are happening in the chest,
when somebody is speaking.
And it's fairly subtle, but it's normal to have some degree of tactile fremitus,
which is simply done by applying, usually the ulnar surface of the hands,
because that's where we're best able to detect vibration
So, as he's speaking, I can clearly feel vibrations in my hands,
as I march up the back of his chest.
And a patient who has again a significant lung consolidation,
those sounds that are coming from his voice box, from his larynx,
are now going to be accentuated as they pass through solid tissue,
so, you'll have increased tactile fremitus that'll be transmitted to my hands.
In contrast, if he had an effusion in there
and remember, dullness to percussion, is going to be the same,
whether it's an effusion, fluid or if it's a solid,
so, dullness to percussion, can't tease those two things apart,
but if there's a consolidation, you'll have increased tactile fremitus,
whereas if there's fluid, those vibrations from his larynx,
are not going to be transmitted through fluid,
so, you would have decreased tactile fremitus.
And by having him speak aloud, I'll feel normal fremitus on one side
and I'll feel the absence of premise on the other side,
if that's where the effusion is located.
Some people say that you should be saying the word 99,
it honestly doesn't matter,
as long as this patient is speaking loud enough,
for you to feel fremitus, they can say whatever you'd like them to say.
So that concludes this portion of the long exam.
Now, we're just going to talk about one last feature that's important to look for.
So, this last feature that we're going to look for is called, “Clubbing.”
And oftentimes, you will see patients,
who have what looks like these swelling, these protuberances,
on the distal parts of either the fingers or the toes.
It's important to realize that, while a lot of the conditions,
that cause clubbing, are associated with hypoxia,
it turns out that hypoxia, actually, has nothing to do with clubbing,
it's just a coincidence, that many of the things that cause clubbing,
also happen to cause hypoxia.
And in fact, many a time if I had a patient with COPD
and medical students identified that this patient has some degree of clubbing,
which they presume was caused by the COPD,
but I have to remind them,
that actually, clubbing portends, some other diagnosis
and oftentimes that diagnosis could be something fairly significant,
like a lung cancer.
So, the best test to identify clubbing, at the bedside is called, “Schamroth sign.”
And it's based on the idea that the lovibond angle,
which is the angle between the proximal nail fold and the nail plate,
should be concave, that means, it should be going inward.
In patients with clubbing, also known as “Acropachy,”
there's increased tissue fibrosis underneath the nail plate,
that pushes that lovibond angle out,
until it's either flat or even potentially a little bit convex.
So, all i'm going to have Sean do is,
lift up his fingers on both hands,
specifically, his ring fingers
and bring the distal digit together
and you're looking for a little tiny diamond,
to show up at that junction between the proximal nail fold and the nail plate,
if that diamond is preserved,
the patient does not have clubbing,
whereas if it is obliterated and that little corner is coming together on both fingers,
then that would suggest that clubbing is present.
Now, clubbing we see it in things, particularly involving the chest,
like bronchiectasis, cystic fibrosis, I mentioned lung cancers,
a variety of different conditions, in fact 80% of the time that you find clubbing,
it is associated with a pulmonary condition, not COPD, to be clear,
the other 20%, are from oftentimes, congenital cyanotic heart disease
and hepatopulmonary syndrome and variety of other things as well.
That concludes our examination of the respiratory system.