00:00
This portion of our video series
is going to talk specifically
about oxygen.
00:05
So, this isn't a really quick
review of what you likely
have already been introduced to
in our other series.
00:11
But I want to show you
the difference
in how you start supporting oxygen
until what happens when
they end up on a ventilator.
00:17
Now there are multiple oxygen
delivery devices, right.
00:21
They can offer different flows
and concentrations of oxygen.
00:25
FiO2, is a fraction
of inspired oxygen.
00:29
So we're going to titrate these
based on the patient's experiences
and the orders that you have.
00:34
So let's take them out the things
that do not include
invasively sticking a tube
into your patient.
00:40
Room Air is 21%.
00:43
I just taught this in my
patho class the other day,
and they were guessing 85, 90.
And really, it's 21%.
00:52
This air that you're breathing
right now is 21%.
00:56
When we put oxygen
onto you in any format,
we're going to increase
the percentage
the fraction inspired oxygen
that you're breathing.
01:05
So let's take a look
at the nasal cannula.
01:07
If you've been in a hospital,
you've likely seen somebody
on a nasal cannula.
01:11
That flow per minute,
if you get it between two and six,
the fraction of
inspired oxygen is 25 to 40.
01:18
What's room air?
21. You got it.
01:21
Simple facemask.
Well, that flow is going to be
between six and 10 of oxygen.
And when we say flow,
that's the number of liters.
You have a little meter on the wall
and you adjust it by a down
and you see a small black ball
move up and down.
01:34
That black ball will be in
the middle of six or 10.
01:37
That means that's the
number of liters of oxygen
the patient is receiving.
01:42
That FiO2 is 35 to 50%.
Remember 21?
Nasal cannula
2 to 6, 25 to 40.
01:50
Simple facemask 35 to 50.
01:53
So depending on how many liters
of oxygen the patient is on,
you'll see there's an overlap
between the simple face
mask and nasal cannula.
02:01
Now, venturi mask
different type of mask.
02:03
Look,FiO2 is 24 to 60.
02:06
If you have a non rebreather
that's 80 to 90.
02:09
And if you have
a high flow nasal cannula,
look at what the FiO2 is.
02:14
Whoa, yeah, that is a supercharged
version of a nasal cannula.
02:20
But please remember
that all of these five examples,
they don't push air
into your patient.
02:27
So your patient has to be
able to inspire on their own.
02:32
So that's when we use
these different five types.
02:35
The goal is not
to intubate a patient
unless we absolutely have to.
02:39
But here's a review of
the different types of oxygen
delivery methods we use,
how many liters they run
at and what the FiO2 is.
02:48
And this is what we would
utilize before a ventilator.
02:52
Now, let's look at what happens
when we put a patient
on a ventilator as far as FiO2.
02:58
So, we've already looked at what
the level of oxygen
that can be delivered
with a nasal cannula
and all the other masks.
03:05
But remember, the patient has to be
able to breathe in on their own
in order for those to work.
03:10
Because you might
have been thinking,
why would you not just keep somebody
on that high powered nasal cannula
if he can get up to 100%?
If they can't breathe
in on their own,
or can't support or protect
their airway that's not effective.
03:22
Remember, as you increase the FiO2,
you're going to increase the
amount of oxygen in their blood.
03:28
As you decrease the amount of FiO2,
you're going to lower oxygenation.
03:32
So it's this dance that we play
based on what your patient needs,
and how we can try and
wean them off that FiO2
We want it to go down
and down and down
till we can pull them
excavate them from the ventilator.
03:46
So that is the fraction
inspirative oxygen
with a patient
who is on a ventilator.
03:51
Let's talk about lung volumes.
03:53
Now if you look at the graph
that we have for you there,
you see that along the bottom,
the horizontal axis is time
along the top is lung capacity.
04:04
And we measure
lung capacity in milliliters.
04:06
So you see as the
patient is breathing in,
you'll see that it's about 500.
And then they breathe out,
it's down with
a tiniest bit still left in there,
And then up and then down,
up and down, up and down.
04:19
That's what we call
the tidal volume.
04:22
Now the tidal volume
on this drawing would be about 500.
04:26
We've got lots of formulas
for you to calculate
what would be the
appropriate tidal volume
to plug into the ventilator.
04:32
But this is what they mean
when they say tidal volume.
04:35
That is that upper limit of how much
air is filling up the lungs
at the top of the breath.
04:41
Up to this point, we've talked about
two types of ventilator settings.
04:44
The first one was FiO2.
The second one was tidal volume.
04:50
That's the volume of air that's
being blown into the patient lungs.
04:54
The third one is respiratory rate.
04:57
Now if we increase
the respiratory rate,
this will increase ventilation,
but it will decrease the CO2 level.
05:03
If we decrease it, it will
likely increase the CO2 level.
05:08
So, respiratory rate is usually set
somewhere between 12 or 22 a minute,
unless they're on
a very specialized ventilator,
or a tiny human, baby,
neonatal kind of client.
05:19
They're going to have
rates way different.
05:22
This is for an
average adult client.
05:24
It'll be set between 12 and 22.
05:27
So know that if the rate
is too high for the patient.
05:29
Their CO2 level will be too low.
05:31
If it's too slow for
the patient's needs,
their CO2 level will be higher.
Just like happens in my own body.
05:40
If I'm hyperventilating,
I'm blowing off CO2,
my CO2 level will go down.
05:45
If I'm sedated,
and I'm not breathing very much
my CO2 level is going to
be retained or higher.
05:53
Now, flow rate is another one.
05:55
The maximum flow,
the ventilator will deliver,
and a set tidal volume
in liters per minute.
06:00
Okay, so flow rate is the
maximum flow. Makes sense.
06:06
So flow rate, the maximum flow,
that the ventilator
will deliver the volume
that's been set in the machine.
06:12
So, if I have on a ventilator,
and it's been set with
a tidal volume of 500 milliliters
flow rate is just how fast that
air is going to be delivered
up to that 500 milliliters.
06:24
Now, you can increase it,
but you might also have a possible
increase in ventilation effect
it can be lowered. But what
do you think's going to happen?
If I increase the flow rate,
what do you think the
impact would be on the CO2?
If I increase it,
it could likely decrease the CO2.
06:43
What if I lower it?
Well, that would do
just the opposite,
it could increase the CaO2.
06:50
Let's look at the very end of the
line in your respiratory system.
06:54
So this is an alveoli.
Should look kind of familiar.
06:58
You see that it's a round shaped
and it's also kind of
damp in there, right?
So I've got the alveoli,
the round shape,
and then those are the capillaries.
07:07
Now, the alveoli is one cell thick,
the capillaries are one cell thick.
07:11
And that's because
there is a gas exchanged.
07:14
Now we need it moist in there,
but look at where the water is.
07:18
Now, you knew if you took,
you dipped your fingers in water
and you flung it at a tabletop,
that water would beat up, right?
It would pull together because
that's what water does.
07:29
The tension of the water
it's pulling together,
that's what water naturally does.
We call that surface tension.
07:36
So if the water was just left
to do what it would normally do,
it would cause alveoli to collapse.
07:43
Because that blue ring
you see in this alveoli
would pull the alveoli together.
It would collapse.
07:50
Luckily, we have a cool thing
in our body called surfactant.
07:52
And that makes sure
it doesn't happen.
07:55
But this is why if someone
doesn't have adequate surfactant,
Their alveoli like
don't stay open and intact.
08:01
And then we have
really poor gas exchange.
08:04
Alveoli need to be
open, intact, and round
in order for CO2 and O2 to
be exchanged in the lungs.
08:11
So without that surfactant
that's what would cause you
alveolar collapse.
08:16
So let me give you an example
of what that looks like.
08:19
Now we've got a close up
of that alveolar wall.
08:21
Now the surfactant molecules,
see them?
You've got the little
head and the two legs,
they kind of push themselves
in between the water molecules.
08:30
Why this is good as it
breaks up that tension?
So that's why the water
behaves itself and spreads out
instead of globbing
all together in the middle,
causing the alveoli to collapse.
Why do you care?
Makes a huge difference in
how a patient can ventilate.
08:45
So look at that little surfactant.
08:48
It's got that round circle on
one side, which is hydrophilic.
08:52
That means it loves philo.
It loves water.
08:56
That's why it's squirms
right in there.
08:58
Then it's got a hydrophobic.
09:00
It hates or think of
it as afraid of water,
and it floats out in the alveoli.
09:06
This is why everyone needs
adequate amounts of surfactant
to make sure that water
that tension is broken up.
09:14
So it stays all around the alveoli
instead of dragging everything into
the middle and causing collapse.
09:22
Another setting is
Positive end-expiratory pressure
PEEP is what you
most often hear call
I don't rarely hear someone call
what is the Positive end-expiratory
pressure setting?
They'll call it PEEP.
09:34
The reason I talk to you about
surfactant just now is because
this is kind of a manufactured way
of trying to get around that.
09:41
If the patient doesn't
have adequate surfactant,
there's a lot of inflammation
going into the lungs.
09:46
This is what we can do, PEEP.
Positive end-expiratory pressure.
09:51
So this is what helps
keep those air sacs.
09:54
The alveoli from
collapsing on themselves.
09:56
We just keep a constant. That's
what it is, a constant low pressure.
10:01
Positive end-expiratory pressure
to help keep those alveoli open.
10:07
Now, there comes some
challenges with that.
10:09
This is what keeps
the alveoli open,
and allows them to be able
to exchange CO2 and O2.
10:15
But as we increase it, there's
increased risk of what can happen.
10:19
So we know that PEEP,
Positive end-expiratory pressure
is the pressure that stays in the
distal airways, right, the alveoli
weighed down at the bottom.
10:28
So at the end of their expiration,
they still have pressure in there.
10:31
So there alveoli,
don't collapse or deflate.
10:35
And you can increase it,
if you're having trouble
with oxygenation.
10:39
but please know that
that comes with risks.
10:41
Depends on how friable or
fragile the patient's lungs are.
10:45
If we have to keep going
up and up and up on PEEP,
we can cause damage or
barotrauma damage.
10:51
So you want to make sure
that you balance that PEEP
that we know we're gonna
get some benefit from it.
10:56
And we have minimized
as much as we can
the risk that's going to
actually happen to the tissue.
11:02
So if positive and pressure
can actually harm the patient
like it can cause trauma to the
alveoli. Why would we use it?
Well, because it's
necessary sometimes
and without it that patient's
alveoli would collapse.
11:15
So who makes that decision?
We'll choose you're going
to be a pulmonologist
and the respiratory therapy
and communication with you
looking at all kinds of
responses and testing.
11:24
So it's done with great care.
11:27
But you have that discussion with
your healthcare professional,
talk to them about what they're
trying to manage this with
what they're trying
to get from the PEEP?
And just be aware to watch
for those pressure alarms
when someone's on PEEP.