Pulmonary hypertension diagnosis | Respiratory system diseases | NCLEX-RN | Khan Academy

- [Voiceover] So, threading a catheter

directly into the heart
might be the most direct way,

the gold standard, of measuring
pulmonary hypertension,

but there are certainly
other ways we can do it.

So, if we think about the relationship

of the heart and lungs in
the cardiovascular system,

we have the heart here, and the lungs,

the next step in where the blood is going,

so here we have our lungs.

In blood, or deoxygenated blood,

well, first let's draw some chambers.

We have four chambers, two on top,

and two on the bottom.

It's from this right ventricle

that we get deoxygenated
blue blood into the lungs.

Remember that everything's flipped,

like the person is
standing in front of you,

so this is the right,
and this is the left.

So, blood goes from the right
ventricle into the lungs,

and then back over into the left atrium.

It's gonna be oxygenated red blood.

So given this relationship,

if we have hypertension in the lungs,

that backs up into the right ventricle,

and then, not putting as much
forward into the left atrium,

then, another way of evaluating the heart

can tell us about pulmonary hypertension.

And this is a task we call echocardiogram,

usually just echo for short.

So, echocardiogram.

This test is basically
putting an ultrasound probe

over the heart in different directions,

and just looking at how
the chambers in a different

compartment of the heart are working.

So, for our purposes of
pulmonary hypertension test,

the echocardiogram can show
us the right ventricle.

The flow going on in there,
how hard it's working,

will give us a clue of
pulmonary hypertension.

We can also see the left atrium,

see how much blood it's receiving.

So this is a very powerful diagnostic tool

in pulmonary hypertension,

is to look at how the
heart is functioning.

But an added bonus, is
that, since we can see

ALL parts of the heart, we can
also see the left ventricle,

and remember that, if the
left ventricle has a problem

pushing blood forward,
then the backup can be

a cause of pulmonary hypertension.

So, the echo can tell us more than

whether or not we HAVE
pulmonary hypertension.

It can also give us a
clue as to the reason.

So it can tell us yes or
no, pulmonary hypertension,

but it can also tell us about
cardiac function as a whole,

which can give us another
additional layer of clue

as to why this patient has
pulmonary hypertension.

So, that's the echo.

And another test that we
might do for patients,

obviously it's done a lot
with any pulmonary complaint,

is the x-ray.

The x-ray involves radiation,

although for a chest
x-ray it's not too bad.

X-ray.

And from the total picture,
we can see if the lungs

are over-inflated,

if there are other clues
of pulmonary disease,

but specifically for hypertension,

the vessels in the lungs,

if they have chronic
hypertension for a while,

they become thickened.

So, for an x-ray, we can see
the markings in the lungs

along the pathway of the vessels,

and the kind of scarring, and
the enlargement that happens

over a period of time.

Usually, we should only
be able to faintly see

the pattern of the
airways and the vessels,

but when there's pulmonary hypertension,

it can be really prominent,

depending on the degree.

So an x-ray is very
reasonable to start out with.

Next, we have some tests that can tell us

how the lungs are performing their job,

so we can do an arterial blood gas.

This analyzes the amount of
oxygen and the carbon dioxide

in the blood, and the
lungs are responsible

for keeping that in balance,

so this is not specific, so

if we have a bad arterial blood gas,

it can tell us that the gas
exchange here is not efficient,

not necessarily that they
have pulmonary hypertension,

but given the history,
combined with the blood gas,

it can tell us how well
the lungs are functioning,

also how bad the hypertension
is, if they do have it.

So, along with the arterial blood gas,

we can also do pulmonary function tests,

which is a direct way to measure exactly

what the lungs are doing, and
what it's capable of doing.

So, we're still gonna put history here

as the most important component

in diagnosing pulmonary hypertension,

or to make you suspicious
of pulmonary hypertension.

These tests can push
you one way or the other

towards the diagnosis, and
of course you can always

thread the Swan-Ganz catheter
to get a definite measurement.