00:01
Under hemolytic anemias,
some things that you want to keep
in mind intrinsic and extrinsic,
I just showed you as to
how things are divided.
00:07
If you have something taking place in
a pathology within the RBC itself,
that would be an intrinsic defect.
00:14
Extrinsic, for example,
let’s say an RBC -- Boom!
Hits a mechanic valve.
00:18
Okay, and then it dies, right?
So that’s an extrinsic defect,
that’s not within the RBC,
the valve is causing damage
and destruction of your RBC.
00:27
Overall, we have hemolysis.
00:31
And the question that you’re asking
yourself clinically is which one?
Is it intravascular or
extravascular type of hemolysis?
Because that will then tell you if your
patient has massive hemoglobinuria,
would mean intravascular.
00:46
Extravascular would mean
significant jaundice,
I will give you more detail
as we go through here.
00:52
Now, what about the destruction?
This is what you want
to pay attention to,
intravascular hemolysis.
00:59
This would mean that there is a disease
in which the destruction of your RBC is
taking place within the blood vessel.
01:06
That is not where your RBC
normally gets destroyed.
01:07
Can we agree upon that?
The answer to that question, yes.
01:11
So what does that mean?
You’re destroying the RBC
within the vasculature,
you are now releasing
your hemoglobin.
01:17
That hemoglobin will most
likely not get further degraded
because this is not at
the level of the spleen.
01:24
This will then get filtered by the
kidney who is the hemoglobin.
01:28
Thus, in intravascular hemolysis, you
would expect to find hemoglobinuria.
01:34
Remember that patient that I’ve been
talking about over and over again
in which he or she wakes
up in the morning,
gets surprised because he or she is passing
red urine or after exercise, right?
That’s intravascular
hemolysis.
01:49
Clear?
Extravascular.
01:53
Where does an RBC go
to get destroyed?
Well, it used to be called the
reticuloendothelial system,
that is more of an obsolete
type of description,
but it’s in reference to those organs
such as the spleen primarily responsible
for destruction of the RBC.
02:10
The spleen is not
in your bed vessel.
02:13
So therefore, your RBC has been
removed from the vasculature.
02:19
It’s taken to the –
You know about the Billroth,
the cords of Billroth,
and you have a splenic
macrophage that will destroy it.
02:27
You will then further
degrade your heme into –
Tell me about your biochemistry.
02:31
Good.
02:31
Heme,
biliverdin –
What kind of bilirubin?
Unconjugated or
indirect bilirubin.
02:40
What does that mean to you?
Lipid-soluble.
02:43
How is your patient
going to present?
Jaundice,
icterus.
02:48
Are we clear?
This is the question that you’re
asking yourself every single time
that we go through
hemolytic anemia.
02:56
I don’t care if it’s
intrinsic or extrinsic,
this will then tell you what
your patient is suffering from.
03:01
Now, let’s continue,
but one more thing.
03:04
That spleen that will be
involved in extravascular,
that’s a little bit of
a problem, isn’t it?
At some point, what if the
spleen gets destroyed?
Now, microbiology, what kind of
organisms are you now susceptible to?
Encapsulated organisms.
03:20
Now, we can move on.
03:23
So, this is a nice little picture here
to show you extravascular hemolysis.