At this point, we’re
looking at the
largest category of anemias
and this would be normocytic.
We’ll begin our discussion by looking at
non-hemolytic anemias with
an MCV between 80-100.
Of all the non-hemolytic anemias,
the ones that students tend to be a little
confused with would be acute blood loss.
And the only reason for that is because
the students feel as though that,
well, the RBCs are being destroyed
because you’re losing it and then
obviously externally they get destroyed.
But understand, when
you’re actually losing it,
they are not being
destroyed on their way out.
So therefore, you still must
consider this to be a non-hemolytic.
And then the reason you call
this normocytic or refer to it
as being normocytic is because
you’re losing equal quantity
of RBCs and then plasma.
So this is whole blood that
you’re actually losing.
And so therefore, when you
actually conduct a measurement,
you end up finding an
MCV between 80-100.
So that will be the trickiest, but
once you understand the definition,
then we can move forward.
And also think as to what you
want to do with this patient.
Oftentimes, it would be a patient
that is feeling hypotensive.
And so therefore, IV fluid is
something that you want to give.
And with that, meaning to say that
IV fluids do not contain RBCs.
That is not packed RBCs, is it?
Major cause is trauma.
Obviously, if there is enough
blood loss and this discussion
would also be in your
best interest to bring
some of those concepts
that we looked at earlier
in nephrology and as to
what actually controls
volume and also controls
And when there is enough
blood loss and volume loss,
then the priority of the body
is to then address the volume
at some times at the expense
of your osmolarity.
And that discussion
we have had prior.
Now with anemia, what else might then cause
acute blood loss?
Well, GI bleeding.
If there is a bleeding ulcer severe enough
or secondary to portal hypertension
and if there is esophageal varices
that at some point
because you’re worried about
rupture and bleeding.
By that, at some point, remember
one of the common causes of painless
rectal bleeding is diverticulosis.
And if there is enough blood loss,
then your patient is going to be in the
state of normocytic non-hemolytic anemia
because the blood is being
evacuated from the body.
Now with all that said, here it is in text.
There is no anemia initially
even though the patient feels as
though that he or she is tired.
Because there is loss of RBCs.
But the fact that you’re losing an
equal proportion of RBC and plasma,
the sign of anemia -- or laboratory-wise,
there is no anemia initially.
However, you know the patient is going
to feel quite hypertensive and fatigued.
let’s say that we leave
the replacement to itself.
Meaning to say, physiologically,
how long does it take for the body
to then replenish, well, this loss?
If we leave it to the body itself,
well, the plasma is the
first thing to be replaced
and that is usually with
the help of the kidney
in which it’s trying to
retain the plasma obviously.
Well, the kidney is not the bone marrow,
so it’s not going to be responsible
for producing RBCs, is it?
However, the kidney is
responsible for releasing EPO.
It does take time for the EPO
to then work on the bone marrow
where it then starts
producing your RBCs.
Now, once that plasma --
Now, there are 2 ways that we can do this.
We can leave it for physiology naturally
for the plasma to then be replenished
or more likely the scenario is going to
be with this type of acute blood loss,
especially secondary to trauma,
the patient is now given saline.
And so therefore, it just replaces the
plasma compartment only, correct?
So if it’s the only compartment that
you’re replacing is the plasma fluid,
then obviously here, you’re
going to then reveal the anemia
diluting the RBCs.
So at first, the whole blood has been lost,
but then once you replenished the plasma,
then it’s the RBCs
that are not there
that, oh, look at this, the
anemia has now been unveiled.
I hope that makes sense.
Then as far as the bone
marrow is concerned,
it takes about, well,
approximately a week,
keep it simple for it to then
respond with reticulocytosis.
What does that mean to you?
It means that now, the body recognizes,
oh my goodness, the RBCs are not present,
and so therefore the bone marrow
has to now churn out more RBCs.
As it does so, well, reticulocytosis.
It’s an immature RBC, about 24 hours, okay?
Completely different from a
previous version of the progenitors
known as your erythroblast