High altitude pulmonary edema is the last
disorder that we’re going to go through.
Its big processes are dyspnea,
which is shortness of breath,
and you can cough up bloody sputum
and sometimes that’s even frothy.
And what it makes it frothy is
sometimes you’re also coughing up
the particular surfactants
that are in your lungs.
There’s also a warmth that is oftentimes
felt in various portions in lung
and part of that process is
probably not only the dyspnea
but the edema portion that
you’re actually sensing.
How does this occur in terms
of its pathophysiology?
Well, it’s not
But there’s a couple of very
good theories out there.
This picture is just showing some of the
alveoli starting to fill up with fluid.
And I emphasize this point because
if alveoli are filled with fluid,
they cannot undergo gas exchange.
You can’t undergo gas exchange and you’re
not getting O2 and not getting rid of CO2.
High altitude pulmonary edema, its
pathophysiology is not fully understood.
However, pulmonary hypertension
seems to be part of the root cause.
And this maybe because of the
increase in pulmonary artery pressure
that occurs during hypoxia.
This pulmonary vasoconstriction is
probably due to that low oxygen
and it might not be uniform
to cross the entire lung.
But what happens that increase
in pulmonary artery pressure
might cause stress failure of
certain pulmonary capillaries.
So let me show you what
that might look like.
So in high altitude
they believe that there is this stress
failure in the pulmonary capillary.
And that can be viewed in
this figure on the left.
Where between the two green arrows,
is where the stress failure occurred.
And that is damage of a
But what is important to think about
this from an edema point of view
is what was in the blood is going to be
spilled out into the interstitial fluid.
That’s going to pull other fluid with it
and you can, on the right side, see the
pulmonary edema in terms of an x-ray.
So how do you try to prevent and
treat high altitude pulmonary edema?
Of course, just like the
other mountain sicknesses,
is very important.
There is some pharmacology that can
sometimes help such as vasodilators,
especially calcium channel blockers,
but the most important thing is to
get the person off the mountain.
They need to descend to a
lower barometric pressure.