hi welcome to our video series on
interpreting lab values
in this one we're going to take a look
at the complete blood count
now we usually shorten that to cbc so
when you see a physician's order
it will say cbc because we shorten
everything in healthcare
so a complete blood count or cvc is a
lab test
you'll have to get a blood sample from
your patient but it's going to give us a
ton of information
about the types and numbers of cells in
the blood
so you can learn a lot about your
patient's health
right then and there from when the blood
sample is drawn so let's take a look at
what's involved in a cbc
now we've got a great picture for you
there this tells you kind of the
percentages of the cells
look that 45 is your packed red blood
cells
one percent is the buffy coat that your
white blood cells and your platelets
and 55 is plasma volume
so that kind of gives you a feel for it
there's three types of cells in the
blood
there's red cells white cells and
platelets
so take a look at that test tube right
there kind of start to get
set in your mind what you have there and
what our percentages are because
we talk about white cells but look what
a tiny percentage
of an average healthy blood sample they
are 55
of that plasma volume can also change
with your dehydration
looking at the packed red blood cells
when you hang a unit of blood from a
patient
that's what you're hanging because we
want to get that oxygen carrying
component in the red blood cells
besides adding all that extra volume
okay now that we've kind of looked at
that
let's go back and take a look at the
different types of cells
we've got red cells white cells and
platelets
now the job of the red blood cells like
we said is to carry
oxygen that's why we want to look
closely at another value on a cbc
the h and h or the hemoglobin and
hematocrit
so when you hear someone refer to an h
and h that's what they're talking about
hemoglobin and hematocrit now why we
care about that is because hemoglobin is
the
oxygen carrying protein in the red blood
cells now adult has four of those when
each red blood cell babies have six that
seems kind of weird doesn't it
when they're first born they've got
extra hemoglobin carrying capabilities
the hematocrit tells us the proportion
of red blood cells
to the fluid component or the plasma in
your blood
so if i have somebody who's bleeding out
their h will go
lower so keep that in mind if i have a
patient who's experienced a trauma
and they've lost a lot of blood that h
will be
lower than normal okay so we've looked
at the first cells
the red blood cells we know their job is
to carry oxygen
now the white cells these are the
infection fighters that's what they do
and the platelets help with blood
clotting and that's a good thing
remember our trauma patient
well we want their blood to be able to
clot because we want them to stop the
bleeding and the hemorrhaging
so we can hang on to their blood volume
so when you're looking at this slide
let's go back and make sure you have it
kind of set in your brain before we move
forward to look at these in more detail
55 of your blood is plasma 45
is your packed red blood cells and one
percent is your white blood cells and
platelets
so think through in your mind what
should make up the largest percentage of
your blood volume
right plasma about the other half of
your blood volume is made up of
packed red blood cells good and the
tiniest percentage
less than one percent is your white
blood cells and platelets
now one more thought before we move
forward think through do you kind of
have in your mind
what's the purpose of red blood cells
don't look at your notes
just see if you can pause and reflect
what's the purpose of red blood cells
what's the purpose of white blood cells
and what's the purpose of platelets
okay ready let's keep going remember
that the cbc
facilitates us identifying anemia
infection
or leukemia and we're going to talk
about how those lab values are
particularly unique to each one of those
things so if i look at a cbc
it might give me a clue if a patient is
anemic meaning they don't
have enough oxygen carrying capacity
because they have low red blood cells
maybe they have an infection you're
going to see those white cells go like
crazy
or a disorder like leukemia
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you