On physical exam, the clinician will
begin by inspecting the patient.
Just look at their breathing effort.
First, you're just going to
look at the shape of the chest.
The lungs can become hyper
inflated in severe asthma,
and the chest can also appear hyperinflated.
Next, you look for the movement of the chest,
including the breathing depth and the rate.
When the patient's airway becomes
too constricted and tight,
and the patient becomes tired and fatigued,
they're not able to move air in quite well.
And sometimes, they might not even wheeze.
This is called a silent chest,
and this is an ominous sign of
impending respiratory failure.
When I have a patient come in to the
clinic and I know they have asthma,
and they come in and I listen to
them and I do not hear wheezing,
this is an example of a silent chest
and this is a high Red Alert.
I will often administer
bronchodilation to the patient
and administer nebulizer treatments,
and then they will start to wheeze.
So they're actually improving
when they start to wheeze.
Then you continue administering
medications to try to treat their wheeze.
Next, you look for any obvious chest
deformities, and you look for retractions.
Here's an example of the retractions.
They're based on mild, moderate, and severe.
So, at the bottom, you see mild,
substernal, and subcostal retractions,
and you actually need to look at the
patient's chest to look for these.
You look under the gown
and under the clothes.
Moderate retractions are noted in the
supraclavicular and intercostal space.
And severe retractions are
in the suprasternal area.
Patients may have combinations of these
and they may move along the continuum
from mild to moderate to severe and back
as you start to bronchodilate the patient.
The next step in the physical
exam is palpation.
The clinician's going to palpate
for symmetric chest expansion,
and will assess the tactile fremitus.
To assess chest expansion,
the clinician's going to place
their hands on the patient's back
with their thumbs pointed toward the spine.
The hands should lift symmetrically outward
when the patient takes a big deep breath.
In the setting of asthma, the
chest expansion is symmetrical,
but the overall chest expansion
may be decreased
if the obstruction is severe
as they trap their air.
Next, you perform tactile fremitus.
So a normal lung is going to transmit
a palpable vibratory sensation
to the chest wall.
This is referred to as fremitus,
and it can be detected
by placing the ulnar aspect of both hands
firmly against either side of the chest,
while the patient says the
words, "Ninety nine."
This maneuver is repeated until the
entire posterior thorax is covered.
The bony aspects of the hands are used
as a particularly sensitive area
in detecting these vibrations.
In the setting of asthma,
tactile fremitus is decreased,
indicating that there's increased
air in the pleural space
and a decrease in lung tissue density.
This happens, again, due to the air
trapping and the hyperinflation.
The next part of the physical
exam is percussion.
This technique makes use of the fact
that striking a surface that
covers an air filled structure,
like the normal lung, will
produce a resonant sound.
While repeating the same
maneuver over a fluid-filled
or tissue-filled cavity will
generate a dull sound.
In the setting of asthma, percussion's
going to reveal a hyperresonant sound,
which is more drum-like because, again,
the air is trapped in the lungs.
The last component of the
respiratory exam is auscultation.
This is where you listen to your patient.
Using a stethoscope,
the clinician's going to listen in
a stepwise and patterned fashion,
comparing sounds bilaterally
and in all fields.
The breath sound should be vesicular.
Now, you may hear an inspiratory wheeze,
an expiratory wheeze, or both.
The improvement or worsening of a patient's
wheezing is important to track
to see if they're improving in their
condition or decompensating.
These are continuous, low-pitched rattling
sounds that often resemble snoring.
During an asthma exacerbation,
one can note diffuse rhonchi
in the expiratory phase,
and this can suggest a
generalized airway obstruction.
Normally, exhalation, when you breathe out,
is a passive action, meaning
it should be effortless.
But during an asthma exacerbation,
the airways are so constricted
and plugged with mucus,
it's hard to move the air in and out.
Since it's so hard to exhale
during an asthma attack,
more and more air gets
trapped inside the lungs.