in this session we're going to focus on
percussion percussion is a technique
discovered fairly recently by Leopold
Olin bruger the story is that he was an
innkeeper son and he watched his father
tapping on casa wine to see how much
wine was left and from that when he
became a physician in the late 1700s he
discovered percussion and everything we
know about percussion he described he
used an instrument that they laid on the
chest and a tiny hammer in fact the
present-day knee hammer has its genesis
from that instrument but we found that
we perk us much better when our finger
is the plexi meter and our other hand is
the hammer I know that there are many
different ways to do this I favor your
putting your hand firmly against the
patient's chest not keeping the other
fingers up because I think it's harder
to form a good seal so push the fingers
in seated nicely in the intercostal
spaces and you're trying to aim for the
middle of this phalanx and it's
important to keep your fingernails short
in order to perk us successfully your
wrists must be loose and if you get all
these things going you will have a nice
percussion stroke that will serve you
very well
you're detecting a slight difference
between left and right and that is quite
normal that is the area of superficial
cardiac Dominus and now we're going to
go over the surface anatomy of the right
side of the lung because if you think
about it there's no point in percussing
and encountering an abnormality dulness
say if you don't know the normal
anatomical boundaries and don't know if
that's liver or lung so I'm going to
point out some of the surface markings
and I'm going to draw them for you if
you were to put your finger in the
suprasternal notch and bring your hand
down you would encounter the angle of
Louie it's a very important landmark
this is a super strong notch because
lots of exciting things happen there
it's the level of the right atrium the
trachea bifurcates the thoracic duct
crosses over.the as Lucas vein joins
that's the lower border of t4 and for us
it's very helpful because the second rib
joins right there and therefore the
space right below it is the second
intercostal space now and percussing on
the right side we we must be conscious
of the location of the major fissure
because the major fissure will divide us
divide things into the upper and lower
lobes and the minor fissure and I'm
going to show you an easy way to do that
without having to remember too many
landmarks and so on so let me let me
demonstrate by having Jeff turn around
for me a second now this is the medial
edge of Jeff's scapula with his arm at
his side so if you if you remember this
this is where his scapula is I'm now
gonna have him put his hand on top of
his head and a really exciting thing
happens is the moment he puts his hand
on his head the lower border of the
scapula becomes a wonderful landmark for
the major fissure so this is the lower
border of the scapula and if I continue
it up and then continue it through the
side like so it will eventually come
meet the costal margin
at about the sixth rib right about there
and then median fissure or the
horizontal fissure is found by drawing a
line from the fourth rib and if you
follow that line it eventually
intersects with the other line and as
you can see the axilla is the only place
where you can see all three lobes of the
lung upper lobe middle lobe lower lobe
when you're examining the patient from
the back you're largely dealing with
lower lobe with a little smidgen of
upper lobe and when you examine the
patient from the front you're mostly
seeing upper lobe with a little silver
of the middle lobe and a tiny silver of
the lower lobe in percussing the right
side it's terribly important again to
know where the liver is and especially
to know the upper border of Liberty on
us because the liver is here it is dull
when you perk us over it you need to
know the upper border so that you can
say any dumbness above that is fluid or
consolidation and the magic numbers to
remember are five seven nine five seven
nine the fifth rib in the midclavicular
line so here's the second rib third
fourth fifth right about there's a fifth
rib in the midclavicular line
the seventh rib in the mid-axillary line
I'm going to turn Jeff a little bit and
have you put your hand on your head and
I'm going to find my landmark again
here's the seventh rib in the
mid-axillary line and the ninth rib if I
can turn you all the way put your hand
down
the ninth rib in the mid scapular line
the ninth rib which is about there so
remember the magic numbers five seven
nine representing the midclavicular line
the mid-axillary line the mid scapular
line if you have down list below that
that's normal that's liver if you have
dauntless above that especially if it's
considered me about that
it's quite abnormal and percussing the
left side of the chest it's really quite
different from the right side on the
right side you have the solid organ of
the liver to contrast its darkness with
the resonance of the lung on the left
side there's a slightly different
situation so on the left side you have
the heart and as I mentioned before you
have an v sized area of dumbness which
we call the area of superficial cardiac
dullness everybody should be dull there
and if they're not it suggests
hyper-inflated lung the pulmonary ii
space again should always be resonant
and if it's not it suggests perhaps an
enlarged pulmonary artery but the very
interesting phenomenon here has to do
with the gastric bubble that sits under
the ribcage here is the lower margin of
the ribcage and the gastric bubble sits
underneath there in an area called trop
space which I'm going to outline drop
space spelled tra ube is formed by
dropping a perpendicular on the sixth
rib in the middle avicularia so here's a
metal bicular line here is the second
rib third fourth fifth sixth
so perpendicular from the sixth rib in
the midclavicular line and another
perpendicular from the ninth rib in the
anterior axillary line and what you then
get is an irregular quadrilateral
representing the stomach bubble sitting
quite high up don't forget the diaphragm
is quite a dome even though the costal
margin is here and when we perk us the
lung and go down this way we go from
resonance typically to timpani from that
large solitaire bubble so listen to this
you hear how it became a much fuller
boxy sound unlike this sound and that
represents the stomach bubble it's a
useful sign because if you have a
pleural effusion
on the left lung it will seep into the
costophrenic angle and it will
obliterate throb space whereas if you
have a consolidation of the lung the
lung will be consolidated the lung sound
will be flat dull and when you come here
trough space will be preserved because
the lung boundaries over there
this represents the costophrenic recess
and so it's a useful sign in that
situation
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Stanford junior University
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