Let's continue. Okay. Now, what is this
pressure support? Well, we have two different
types of positive air pressure. And you want
to be familiar with both types. Extremely
common when you do your rotations. We already
talked about CPAP. That means continuous positive
airway pressure. Now, used to be once upon
a time, that this was cheaper. That was important
for you to know, wasn't it? Because if you
find that CPAP was cheaper than BiPAP and
you had two answer choices, you would go with
CPAP. But, understand. Now because of advancement,
BiPAP is economically just as reasonable as
CPAP. Now what does that even mean? So, continued
mean that you are going to introduce positive
pressure into the airways so that you can
do what? Good. Increase the volume of the lung.
So, what does BiPAP even mean? Well, our discussion
earlier, when we talked about severe respiratory
failure type 2. What does type 2 respiratory
failure mean to you? Good. Apart from the
fact that you have hypoxemia with a PO2 less
than 60, you also have retention of carbon
dioxide. What's problematic? Definitively
above 40. So now you are retaining your
carbon dioxide which means you have impairment
of your exchange. May I ask you something?
What might you want to do as a clinician so
that you can blow off that carbon dioxide
which is type 2 respiratory failure? Just
because you introduce oxygen into the alveoli
which is CPAP, which is something that you
want to think about in terms of managing a
patient with obstructive sleep apnea, and
that might be effective there. But just because
you are introducing oxygen into the alveoli,
does that mean that you are blowing off your
carbon dioxide? How do you blow off your carbon
dioxide? Oh, exhalation. So, why not come
up with technology or technique or maneuver
or pressure support which then allows not
only for the patient to then be introduced
with air, but then also what? Good. Exhalation.
This is bilevel positive airway pressure.
Welcome to BiPAP or BPAP. Both one and the
same. By Bi-level, we mean that not only are
you assisting your patient with inspiration
airway pressure, but you are also doing what
please? You are also helping the patient
blow off that carbon dioxide with expiration
or exhalation. Is that clear? Of the two answer
choices. So here you have identified a patient
with COPD. You found that the pH has
decreased. Okay. You find that the CO2 is
elevated meaning above 40. So, you tell me
what kind of respiratory failure? Type 2.
What type of ventilatory support would you
like to then provide? You have two answer
choices that you have now dwindle it down to.
CPAP or BiPAP? You will correctly and
confidently choose BiPAP. Because
you want to get rid of that carbon dioxide.
Is that clear?
Now, as we move on, we will then talk about
ETT. It stands for endotracheal intubation.
So, if your patient, and we will talk about
this upcoming. But endotracheal intubation
and ventilator, well, here, there are certain
goals and objectives that you want to keep
in mind at this point in your education and
then as you move on into rotations and when
you actually insert it or intubate your patient,
well there are other things that you will
move into further detail. Let's take a look
at the graph, shall we? So, we have the patient
down at the bottom with flow. So, flow
inside into the lungs means what to you? Inspiration.
Inspiration, hence the hump. So the flow
is going to increase into lung during inspiration.
Is that understood? Do not confuse this with
the loops that we did, loop spirometry. Can
we quickly recap that? Because that is important
and that we want to make sure you have in
your head with great detail. That loop spirometry
that we looked at, at the upper half was what?
Expiration. The inner loop was what? Inspiration.
That is different. Is that clear? This is
strictly in terms of your natural breathing.
The flow is what you are paying attention
to. The flow is going to increase into lung
upon inspiration. Okay. So now this patient
requires help. And remember, once again, you
want to make sure that you reach a nice and
plateau level in which there is enough air
that you are introduced through inspiratory,
IPAP, stands for inspiratory positive airway
pressure. You have a minimum and a maximum
threshold. So right in that middle is where
you wish to be. As far as you as clinician
So therefore, you keep increasing the positive
pressure. What does that mean to you? You
are introducing air into the lungs. Good.
What is the physio? The physiology without
the ventilation means negative pressure. Keep
those separate. So now, you are being the
lungs, you are introducing positive pressure,
you introduce positive,
so that you introduce more air into the system,
but you do not go beyond the max. You see
the top dash line? That is the max. Why?
You go above max, you might be introducing
quite a bit of, well, injury to the alveoli.
Remember, you don't want to get to the point
where it gets so big that you are causing
damage. Maybe tension pneumothorax or maybe,
remember that conversation we had where,
and we'll talk about this again, not to
worry. If that alveoli becomes so fat and
you have a fat alveoli in your lungs, guess
what? You are compressing the adjacent structure.
What is that adjacent structure? Good. Your
pulmonary capillaries. You knock that out,
you'll have all kinds of issues. Pulmonary
hypertension, may be right-sided issues. So,
your target, what you see there, at the very
end of the graph, on your right, it says target
VT. What VT mean? Tidal volume. So, this
is a patient that requires help to reach a
target volume or tidal volume in which the
patient is able to breathe comfortably having
proper gas exchange. Let's take a look.
So, we talked about BiPAP. ETT stands for
endotracheal tube. Patient initiates a breath,
then gets support with it. And usually, a
backup rate is always set. Okay, so that
is more of a clinical type of backdrop,
but there is the full picture of what you
are doing here with pressure support. Your
graph becomes the most important point. Understand
what a BiPAP is and we talked about that
in great detail.