Voiceover: In talking about treating emphysema
I think the most important thing,
the first thing to talk about is to stop smoking.
Out of all the therapies this is the only one
that will stop the disease from getting any worse.
Since smoking can cause emphysema
it's like the first way to get out of the hole
is to stop digging it any further, right?
Stop smoking that's the first one.
In terms of drug therapies
they can't reverse what's already been done
but it can help with the symptoms
and I think it's important to divide it
between chronic therapies and acute.
Chronic is what a patient would take everyday
to maintain their status.
Acute is when once in a while
emphysema can have exacerbations.
They can get a whole lot sicker really quickly
and we use a different combination of drugs
to get them through that acute disease.
An important first class of drugs
in the chronic maintenance therapy
I think are the bronchodilators.
Broncho which refers to the airways.
Dilator just refers to the fact
that these drugs get your airways to open up
like a tube that becomes bigger in diameter.
If this is our airway tree like this.
Branching and branching off.
If I take a cut right here
so that we can look across this tube
it will look something like this.
You have the outside and you have the lumen
which just means the inside where the air goes through.
In here in the walls of the airway
it's actually full of smooth muscle.
Smooth muscle are not skeletal muscles.
We can't control it with our mind
but a combination of things in the body
like the nervous system and other conditions
affect how tightly wound this muscle is.
Smooth muscle.
The way that I've drawn it here
is actually pretty tightly wound.
Look how small this lumen is becoming
as the muscle tightens.
The muscles contract this way
to squeeze down on that lumen.
The bronchodilators can open up that airway.
The lumen we'll draw it as this big
because the muscles around it have relaxed a little bit.
It's not so tightly wound anymore.
See how much room this gives us in the middle.
That will allow a lot more air through it than
this little lumen back here.
The bronchodilator is actually an umbrella term
and includes several classes of drugs
but all of them share the effect
of opening up that airway.
The first class of bronchodilators I want to mention
are the beta2-agonists.
They stimulate the beta2 receptors.
Beta2 receptors are part of the
sympathetic nervous system.
This is the fight or flight response.
As part of it it wants to open up your lungs a little bit.
Stimulating the beta2 receptors will do just that.
One drug you might have heard of in this class
would be albuterol
and actually the drugs in this class
all end with something -rol.
it's an easy way to recognize
and just from the names that can make no sense in English.
The second class of drugs would be
the anticholinergics which are ...
Anti so they are antagonists
which means it turns off the receptor.
This involves different receptors on the airways
but the effect is the same.
In these drugs their names often end in opium
and it has nothing to do with the drug opium.
It's just a coincidence like that.
Broncholators open up the airway
but one of the reasons
that they're constricted in the first place
is because there's too much inflation.
The next class I want to talk about
are the leukotriene inhibitor.
Again, what are these words?
They mean nothing in English.
Leukotriene is an important player in the cascade
that leads to inflammation.
For example, in the cascade
if we have A leading to B leading to C,
leading to D and so on,
eventually at least to leukotrienes
which here I'll just write LT for leukotriene.
This is the goal of the inflammation cascade.
I want to get here to cause inflammation
which includes restricting the airway and other things.
Obviously by inhibiting leukotrienes
we toned down in the inflammation.
It gets rid of some of the mucous
and the constriction in our lungs
that we're fighting in the first place.
Especially in emphysema, toning down
the inflammation is a big deal
because inflammation is how we get so much
neuotrophils and elastase.
Toning down the inflammation by
inhibiting some of the leukotriene
helps the disease from getting worse as quickly.
A lot of emphysema patients can take these
chronic medications everyday
but unfortunately sometimes they can still develop
an exacerbation or a flare
where the compensation system they have in place
is not working all of a sudden
and you get much sicker really quickly.
Our goal here is short term,
get them back to their baseline.
One of the first things we give them are antibiotics.
Antibiotics.
Sometimes when they come to the hospital
they already have an infection
but if they don't we still give them antibiotics
for prophylaxis which just means that
disease hasn't happened yet.
We're giving it to prevent it,
prevention just in case.
Because when they're having an exacerbation
their ability to deal with infection goes down.
As a general rule in the body
anytime you have blockage
or things not moving the way they should
there can be infection behind it
because our body is constantly clearing things
out of our system.
In emphysema for example if you have these
dilated airways, these walls
and the air is trapped back here
in exacerbation that gets even worse.
Imagine all these collapsed airways.
Now all the things moving out are not moving,
are not working great in emphysema to begin with
and now they're even worse.
We have a dramatic increase
in the possibility of having an infection.
There's bacteria in the lungs all the time
and the lungs try to clear them.
Now we're spinning out of control in this flare
and the usual system to clear this bacteria
is not working well so we give them antibiotics.
Just because they have a pneumonia
or some other infection on top of everything right now
that would be horrible.
We want to do everything we can to prevent that.
Antibiotics.
The next thing in terms of inflammation,
we got to give them a huge dose or something.
We got to pull out the big guns here.
We want to give them some steroids.
Steroids are the universal
tempering down the inflammation big guns.
We have our cascade again.
A leading to B to C to D dot, dot, dot.
Eventually to leukotrienes.
Steroids work much earlier in the cascade.
Let's say it works in step C.
We usually give them a pretty big dose
and the cascade stops right here.
Now that's good for preventing inflammation
but since this is a cascade and it's connected
so D is also not working.
All the other things that branch off of C and D,
the other arms of the immune system
which inflammation is part of
are also not working.
With all these things out of commission
yes,our inflammation goes down.
That's our goal.
At the same time it also takes down the immune system.
They're immune compromised
during their steroids treatment.
Immune system down.
This makes the antibiotics even more necessary
but also this is why we try to not give people steroids
for a long, long time.
This is like an emergency save
of our cars running down the hill.
We need to stop it first
and then we can think about
how to get back on track.
That's steroids and another thing.
This person can't breathe
or having trouble getting air in and out.
You come to the hospital.
It might seem kind of logical to put them on oxygen, right?
In the hospital we put oxygen on people
at the job if they had
anytime they have breathing problems.
I'm gonna put a question mark here by oxygen
because this is actually kind of tricky
in emphysema patients.
To explain that let's talk about the respiratory drive.
Respiratory drive is a combination of mechanisms
in the body that make you breathe.
You notice that you don't have to
think about breathing all day long.
That's because between your brain and the nervous system,
your lungs there's a system in place
to make you breathe.
Now usually let's say you're supposed to have
this much oxygen.
This is O2.
And you're only supposed to have
this much carbon dioxide.
When you breathe carbon dioxide is going out.
It's going out and oxygen is what you want to take in.
Usually the body is very sensitive to these levels
exactly where each one is.
Usually the brain is programmed in such a way
that if our CO2 goes up
this is what stimulates us to breathe.
Our respiratory center is more centered on extra,
having extra CO2.
Emphysema is an obstructive disease, right?
We always have too much CO2
and since that's chronic
the body is smart, it learns after a while
that this patient is just gonna have
a little more CO2 than usual.
Look at this new dotted line.
That's our new normal.
We also have a little bit less of oxygen
because our lungs are so inflated
it's hard to take in more air.
This is our new O2.
These are new CO2.
Now since our CO2 is always above that line
stimulating us to breathe,
the body is like okay, I get it.
I'm gonna change my signal.
In emphysema patients
the lack of oxygen here this level
is actually what drives them to breathe.
The respiratory drive has shifted
from CO2 driven to O2 driven.
They need to constantly be reminded
that they lack oxygen to breathe.
In our patient with an O2 heavy respiratory drive
if you give them oxygen what happens?
That oxygen goes up and we lose our respiratory drive.
Ironically giving them oxygen
can decrease their drive to breathe
and that's the last thing you want
in somebody who's having an emergency with breathing.
Also the body chemistry and pH
it's all used to having a little more CO2 than usual.
Suddenly giving them oxygen
can actually knock this system off balance.
It has to be given with caution.
If somebody is given oxygen
their breathing has to be monitored
and making sure that they're still breathing
and really, if they really lose that respiratory drive
their machines with masks
they can take over that drive
and make sure that people breathe.
This is a quick overview
of some of the drugs that we use to treat emphysema
whether it be everyday or acutely,
but most of all they have to stop smoking.
If smoking's what caused their emphysema
stop now before it gets worse
and if they got emphysema through another way
then definitely stop smoking
to reduce the number of flares they have
and to lessen the burden on the lungs
and to stop digging further in this hole.