Articles

Complete Blood Count / CBC Interpretation (Leukocytosis)

November 16, 2019


welcome to another MedCram lecture the
first in the series that we’re going to talk about as we go through the CBC is
the WBC and we’ll talk about increased WBC here under the term leukocytosis
okay so a couple of points regarding leukocytosis you know we’re looking at a
patient most typically in the hospital but this could also be seen as an
outpatient as well you should know that the normal range is about 4.5 to 11 and
then you’ll have this term times 10 to the 9th which is like a billion divided
into one liter so how many cells you see in in one liter so obviously anything
greater than 11 is going to define leukocytosis okay but it can go as high
as a hundred thousand you want to watch trends as we talked about in the first
video so you know a 13 on a white blood cell count may be elevated but if the
previous one was 20 and it’s coming down to 13 then that’s a process that’s
actually resolving and 13 is not to be worried about if on the other hand
you’ve got a 5 and it’s going to 13 that’s something that obviously we need
to worry about more okay so again as always watch the trends and then
differential so the white count as you may know our white blood cells that’s
what the leuco means that’s white so these white blood cells are part of your
immune system but these white blood cells are actually a collection of other
cells there are bands there are segmented neutrophils we call those
CEG’s and these all sort of make up your
neutrophils but then you also have lymphocytes you have monocytes you also
have eosinophils okay so they all have their own function typically the bands
and the neutrophils are seen elevated in pyogenic infections lymphocytes can also
be elevated but they’re usually more typical for viral okay so be aware of
that you also may see this in tuberculosis same with monocytes you
might see monocytes elevated in tuberculosis and also certain viral
infections the one that you should know about though is eosinophils anytime you
see elevated eosinophil you need to think about two things
specifically one is either an allergy also think about parasites
so think about drug allergies if you see high eosinophils think about parasites
and there’s also a third thing that you should think about is well I’ll put it
up here and this is just to keep in the back of your mind is Coxie coccidia
mycosis which is a fungus that typically lives in the Southwest United States
also in parts of South America Central America and that’s a famous one that
they like to use I bring it up because that’s where I live in this part of the
world where we see coccidia mycosis and yoson Affiliate is a nonspecific thing
that you might see but think about coxy think about allergies think about
parasites if you see elevated eosinophil there’s other things that can do it but
that’s one of the things that can do it but the one that you’re probably going
to see the most are these bands CEG’s neutrophils and that will be elevated in
pyogenic or bacterial infections and there’s usually a range so typically
what you would see in terms of percent is maybe about 60 percent will be bands
and CEG’s maybe about 22 or so percent and this won’t add up to 100% but around
20 percent or so for lymphocytes about 5% for monocytes maybe 2 to 4% for yo
sinha fills okay if you see a deviation from that then you know that there is a
simple line that is increased so if this lymphocytes all of a sudden shoot up
think about viruses if this segments go from 60 to 80 or 90 think about a
pyogenic or bacterial infection if instead of 4% you’re at 20% start
thinking about what we talked about coxy allergy or parasites so we talked about
what’s normal we talked about watching the trend we talked about the
differential let’s talk about causes and what to do if the white count starts
going up on you on a patient in the hospital so in terms of causes the big
four that I want you to know our infection steroids
cancer / leukemia or a catastrophic event and these are kind of listed in
order of the most common let’s talk about infection first so typically
with infection you’re gonna see something called a left shift and what
that means simply is that bands are basically released from the bone marrow
and then it becomes segmented in neutrophils okay otherwise known as PM
ends what happens is you see of very little bands and a lot of CEG’s normally
and when you have an infection the bands start to be released more and more and
so you see the bands start to go up in circulation they’ll actually tell you
how many bands there are if you start to see bands in circulation that’s a very
good indication that what you’re dealing with with an elevated white count is an
infection the things that you want to look for clinically look for fever that
will also tell you that that’s what it is that’s going on look for signs of
infection okay the other thing to do is ask the patient
do they have pain that’s usually a sign that there’s an infection somewhere so
look for corroborating evidence that there is an infection going on if you
can’t find it start to do diagnostic tests to confirm it so things that might
be able to do it chest x-ray get a urinalysis
you might even need to get a CT scan to look if the patient has a fever and is
altered by all means get a lumbar puncture to rule out meningitis the
biggest infections are pneumonia which you’ll see on a chest x-ray a urinary
tract infection which you’ll see on a urinalysis look at their skin see if
they’ve got cellulitis somewhere examine their belly see if they’re tender think
about cholecystitis think about diverticulitis all of these things are
going to cause an elevation in the white blood cell count okay the other thing
that you’ll see is steroids so a lot of time people will come in and they’ll
need steroids for either a COPD exacerbation or they’ll need steroids
for an asthma exacerbation and you’ll put patients on stage for whatever
reason what you’ll notice almost invariably
is the WBC count is going to go up now why does the WBC count go up it goes up
for three reasons and this will help us decide and distinguish between why it
might be an infection okay the first reason is is something called D
margination what does this mean here’s your vessel with the white blood cells
the middle of it what you don’t realize is that their white blood cells are
already adhered to the wall and so what happens is the steroids cause these
cells to come into the center of the blood vessel so when you draw the blood
you’re gonna get more of those white blood cells in your sample that’s de
margination about 60% of the effect that we see with an elevated white count is
from D margination now the other thing that might cause this is delayed
migration so everybody knows that these white cells go out of the blood vessel
and into the tissue that’s where they fight infections in the tissue well if
you delay that migration of cells of white blood cells into the tissue
they’re going to be more likely to be in the blood vessel when you draw the blood
and get the leukocytosis and we see that about 30% of that effect is due to that
the last one that we see here is about 10% of the effect and that is bands
released from the bone marrow but this is such a small proportion of the reason
why the white blood cells go up so small that in fact we can actually look at
this situation and say that if you see the bands going up significantly it’s
probably not from steroids it’s probably an infection and that if we see all of
the different white blood cells going out for instance we see the lymphocytes
and the neutrophils and the monocytes and they’re all going up proportionately
that’s usually a result of D margination and that’s typically what we’re gonna
see in steroid use so if you’ve got a patient has pneumonia and you put them
on steroids because they’re having a COPD exacerbation because of the
pneumonia and the white cells go up but you don’t see a left shift you don’t see
band emia then you can probably chalk that up to steroids
within reason right steroids are only gonna make the white blood cell go up
you know maybe from 12 to 20 at most okay if you start to see 30 40 50 then
there’s gonna be a problem speaking of which if we go back to infection on
number one there is a very famous infection that I would be remiss in
mentioning that we see in patients especially in the hospital and that
corollary is c-diff okay I don’t want you to miss that if you start to see
white counts in the 30 to 40 to 50 and higher range okay so these incredibly
high white blood cells something you have to think about is Clostridium
difficile colitis and in this situation you typically do imaging like a CT scan
to look at the bowel wall and you’ll see thickening of the colonic wall in that
situation typically the treatment includes pio vancomycin not IV
vancomycin but pio vancomycin and either Pio or IV flagyl there are other
treatments there’s even surgical treatments so the earlier you catch this
the better so think about seed if if you have a
very very high white count okay so we talked about certain types of infection
we talked about steroids causing elevated white-blood-cell the other
thing that can do this is if there is a leukemia of course remember with
leukemia and lymphomas there’s a problem with the production or their survival of
these white blood cells so in other words there is some sort of gene that
gets turned on and these white blood cells start dividing rapidly and so
you’re making a lot of these and other potential reason why you could have
leukemia or lymphoma is if the cell doesn’t die and doesn’t involute and
just hangs around so there’s different variations on this of course you know
that there is acute lymphocytic leukemia there is chronic lymphocytic leukemia
there is acute myelogenous leukemia which is a really bad player and then
there’s chronic myelogenous leukemia that’s the one with the Philadelphia
chromosome etc so all of these can do it the thing that you must remember or one
of the things that you should remember is something called lap or leukocyte
alkaline phosphatase and this is the stuff inside the cells that is
responsible for breaking down and killing bacteria well in cancer cells
each cell has a lower amount of this leukocyte alkaline phosphatase so in the
old days before we had flow cytometry and more genetic ways of figuring out
whether or not there was a leukemia or lymphoma what they would do is check
score okay and if there was a high leukocytosis but a low lap score that
was indicative of cancer leukemia if the lab score was elevated that means that
there was an appropriate amount of leukocyte alkaline phosphatase in these
cells and that probably wasn’t it so what should we look for again if it’s a
lymphocytic leukemia obviously we’re gonna see elevated amounts of
lymphocytes and so if you see a high white count and they’re almost all
lymphocytes think about this as a diagnosis if on the other hand you see
various different types of myelogenous type of cells myelogenous meaning
segmented neutrophils or eosinophils or monocytes things of that nature then
that would be something along the lines of AML or even CML depending so these
are divided okay what you really need is a peripheral smear and you need a
pathologist to review the cells to see if they look atypical if they look
atypical then you need to get even deeper and you might even need a bone
marrow biopsy done to evaluate for that okay and then the last thing that we’re
going to talk about is catastrophic event so a catastrophic event like a
myocardial infarction or a cardiac arrest or a massive pulmonary embolism
is such a stress on the system or even surgery could be a stress on the system
that this would cause a transient increase in the white count so what you
would see is a bump up very quickly and then the white count would come back
down again as you were to track it okay there are many other things that can
cause leukocytosis that I have not included here even a cold shower can
make your white count go up so think about these things as you look at your
WBC on your CBC thanks for joining us

No Comments

Leave a Reply