So, now that we've reoriented ourselves,
to basic lung anatomy, with the upper lobe
the middle lobe and the inferior lobe.
As shown here and keep in mind,
that on the left side of the chest,
there's just an upper lobe and a lower lobe
and then a smaller lingula in the middle.
Now, we're going to talk about
the different kinds of things
you're actually trying to find,
when you listen to the lungs.
And the first I’m going to talk about is,
just basic breath sounds.
And the types of breath sounds and that
you can auscultate with your stethoscope,
again, the diaphragm, are either vesicular,
bronchial or something in the middle,
which you guessed it is called bronchovesicular.
So, let's talk about the difference
between these kinds of sounds.
I encourage you to actually
take a listen to yourself or,
if you're with somebody else
you guys can listen together
and just start by putting your stethoscope,
on the lower lung field in the back
and listen and describe what you hear.
So, vesicular breath sounds are light feathery
and you may also note that, inhalation
is somewhat louder than exhalation,
the exhalation you may hear the beginning of it,
but it trails off very quickly.
Now, I want you to contrast that,
with the sound that you might hear,
just lateral to the sternum
and I encourage you to make sure you're listening
to the right side of the sternum,
because on the left you're of
course going to hear the heart,
which will confound things.
So, just listening to the
right side of the sternum,
either on yourself or again on a friend,
take a few more deep breaths.
Now, it's a subtle distinction,
but you'll note that there's
the beginning of something,
that we would call,
“Bronchial breath sounds.”
While you're still hearing that
feathery light vesicular breath sounds
in the background, you're
also now starting to hear
something that's a little coarser,
a little bit more robust and
rougher around the edges.
Still, you're hearing more
inhalation than exhalation,
but there's the beginning
of a transition point there,
that's because I’m listening
over the main stem bronchi
and the large airways of his
lungs, in the anterior chest.
The next step, is we're going
to listen to the trachea.
So, put your stethoscope,
right over somebody's trachea
in the anterior cartilage there.
And again, you can do this on yourself,
or you can do it with somebody else.
And now, what we're hearing is
very coarse harsh breath sounds
and you'll note that, inspiration and exhalation,
are essentially identical in volume and pitch,
there's also less of a chorus
of noise, it really is,
more of a specific pitch that you're hearing
and this is characteristic
of tracheal breath sounds,
but it's basically representing or
another way of mimicking, so-called,
“Bronchial breath sounds.”
Now, vesicular breath sounds is normal,
you should hear those in all
the peripheral lung fields.
Bronchovesicular, should only be heard here,
at the areas just lateral to the sternum,
but bronchial breath sounds, what we
were just hearing over the trachea,
is not normal, is abnormal
everywhere in the chest,
you should not be hearing
bronchial breath sounds because,
what they represent, is
essentially, the sound of air,
moving through the upper airways,
but going directly through
some sort of solid tissue,
to the chest wall, where you're
listening with your stethoscope,
without any of those light feathery
vesicular breath sounds along the way,
which tells you that, there's
something that is preventing air,
passing through the normal lung parenchyma
and producing those light feathery sounds
and that's typically going to
occur with either a cancer,
a large mass in the chest,
or potentially a socked in, low bar pneumonia,
which is just transmitting those
vibrations, in the large airways,
all the way through the chest
wall to your stethoscope.
In addition, you also want to look
for adventitious breath sounds.
These are the sounds that, are in addition,
to your simply description of
the breath sounds themselves,
you're looking for things like
crackles, rhonchi and wheezing.
Crackles, is a somewhat of a vague term,
but it actually is describing the
particular acoustics of what you're hearing
and we typically describe crackles, as
either, fine or dry crackles or wet,
also known as coarse crackles and
fine dry crackles, we associate with,
interstitial pulmonary fibrosis
and things of that nature,
that is more of a chronic
indolent progression of disease
and they can be really replicated by
just pulling pieces of velcro apart,
they're very fine, crisp,
there's many different crackles,
that are occurring within a short span of time
and they have a higher pitch, in general.
In contrast, wet crackles, so-called,
because they're oftentimes
associated with heart failure,
with just a little bit of
extra fluid in the alveoli
and they're snapping open
when you take a deep breath.
Those wet crackles, are fewer in number,
they are a little bit higher in pitch,
they're a little bit longer and
you're going to correlate them,
with how high they go up in the back of the chest,
that may give a sense as to how significant,
somebody's heart failure may be.
The next part of, adventitious
breath sounds is, "Rhonchi."
And rhonchi essentially
are, non-specific findings,
that essentially just suggest that there's
some mucus lining the upper airways,
they don't have a lot of clinical
or diagnostic significance
and oftentimes simply coughing will
clear those rhonchorous breath sounds.
We always think of wheezing
associated with asthma and COPD.
And wheezing is essentially a chorus of sounds,
that you're hearing, as there's
increased turbulent flow,
through all of those tight airways,
that we were talking about before,
that tend to collapse,
particularly the setting of COPD.
They should be fairly distributed
throughout all lung fields
and you can categorize them as,
“Scattered wheezing” or “Diffuse wheezing,”
when you're describing it on the chest.