00:01
We've divided the phases of ours
into about three categories.
00:05
Now, you can spend a lot
of time arguing that these
there's a lot of debate about
what goes where and exactly when.
00:11
But I'm just going to
give you a rough range.
00:13
Okay, there's three phases.
00:16
Sometimes people
call them stages.
00:18
You may call them
whatever you like.
00:20
Let me give you an overview.
00:22
The first phase is often called
the injury or exudative phase.
00:27
Now, it usually last
one to three days.
00:30
But it can last
up to seven days.
00:33
I know that can be overwhelming,
as a student like so, is it 1?
Is it 3? Is it 7?
That's the deal with ARDS.
00:40
Not everyone progresses
through it at the same phase,
or at the same rate or in
the same number of days.
00:47
That's why we're giving
you reference ranges.
00:50
So first of three phases,
the injury or the exudative phase.
00:55
Next up,
you'll see we've got 7 to 14 days.
00:58
This is called reparative
or proliferative phase.
01:03
Reparative or
proliferative phase.
01:06
Reparative or
proliferative phase.
01:10
Yeah, that was repetitive because
there's a lot going on here.
01:14
So I want you to know
that these 7 to 14 days,
cells are just going crazy.
01:20
We got a lot of things
happening in here.
01:22
So we're going to spend time in
both of these first two categories.
01:27
The last category is
called the fibrotic,
or the chronic/late phase.
01:32
This is what not everyone
ends up stuck here, right.
01:36
But this is a bad deal.
01:37
We've gone on past
a couple weeks,
but lung tissue is really been
replaced with fibrotic tissue.
01:44
Remember why that's a bad deal
because we're talking
about compliance, right?
Recoiling fibrotic tissue
is not very compliant.
01:56
So it's not very efficient.
01:59
So we've used repetition,
but let's go back through it
First phase,
injury or exudative.
02:05
Second phase,
reparative or proliferative.
02:09
Third phase, fibrotic and remember
not everyone gets stuck there.
02:14
But sadly some people do,
because ARDS does have a
certain mortality rate.
02:20
Now we argue about
it in the literature.
02:22
This study has this one,
this study has that one.
02:24
Let me just tell you this
can be a life-threatening
and an life-ending
event for your patient.
02:31
So let's just take it serious.
02:32
We won't argue about the actual
numbers of what the mortality rate is
and let's just know we've got to do our
best to respond to this urgent crisis.
02:42
Let's serious talk.
02:44
Let's just talk about something that
you can pull out of your knowledge.
02:48
So let's talk about the
three important things
for effective gas
exchange in the alveoli.
02:53
If you've been hanging out with us in
this video series, you already know this.
02:57
But let's just use
this as a review.
03:00
Now the picture is a hint.
03:02
It's a really big clue.
03:04
What's in this picture
that helps you know?
What are the three important
things for effective gas exchange
in the alveoli, okay?
So first,
intact alveolar walls, huh?
This is sounding
familiar, right?
Intact alveolar walls with two types of
epithelial cells (type l and type ll).
03:26
Remember type l,
the elegant CO2O2 exchange.
03:31
Type ll, our cuboidal
surfactant spitter outers.
03:34
There you go.
03:35
So we need an intact
alveolar wall.
03:38
We need an intact capillary
wall of endothelial cells.
03:43
And we need surfactant to
reduce surface tensions.
03:47
Hey, so same thing we
needed for compliance.
03:51
Exactly, when the lung is
functioning effectively,
it has the intact alveolar
wall, intact capillary wall
and it has surfactant that
both allows the lung to be.
04:03
Compliant and have effective
gas exchange in the alveoli.
04:09
You got it, good deal.