Complete Blood Count (CBC) Case – Lab Results Interpretation: Thrombocytopenia & Leukocytosis

By Adem Lewis / in , , , , , , , , , , , , , , , , , , , , , , , , , , , , , /

welcome to another MedCram lecture
we’re going to talk about a case which is gonna illustrate the need for
understanding laboratory data okay so let’s get started we have a 60 year old
Caucasian male who presents with diarrhea and hypotension fever chills
and dizziness vital signs his temperature is 38.3 his
pulse is 135 his respirations are 30 and his blood pressure is 85 over 55 on
physical examination he is alert and oriented times 1 to 2 he is lethargic on
head ears eyes nose and throat examination it is clear
but his mucous membranes aren’t dry on cardiovascular exam he is tachycardic
and on lung exam he has clear to auscultation bilateral
lung fields on abdominal exam it is tender to the left lower quadrant but no
rebound and on extremity exam there is no clubbing cyanosis or edema
laboratory values look like this his white blood cell count is 55.0 his
hemoglobin is 16.0 his platelet count is 85 and as haematocrit is 48.0 his
chemistry’s look like this his sodium is 145 his potassium is 3.0 chloride is 115
his bicarbonate is 13 his be–when is 30 his cratan is 1.5 and his glucose is 200
chest x-ray is clear and the KUB is non-specific he gets a CT scan of the
abdomen and it shows wall thickening in the sigmoid colon you ask further
history and the patient has had a UTI in the past for which he has gotten
antibiotics okay so by this point some of you would probably already know the
diagnosis here this guy just looking at him there’s several things that you can
look at you can see that his blood pressure is low and that his pulse rate
is high this is consistent with hypovolemia but it’s also consistent
with septic shock and given the fact that the white blood cell count is
definitely elevated would lead you to that the kind of IV fluids that you
would want to give are resuscitative fluids so that you could expand the
volume one appropriate type of IV fluid be normal saline however there’s recent
evidence that shows that giving balanced fluids especially in patients with renal
insufficiency will be beneficial and so another probably more appropriate fluid
would be lactated ringers or LR another one that you could give would be half
normal saline with 75 milli equivalents of sodium bicarbonate so what you’re
doing here is instead of just giving pure chloride you’re giving lactated
ringers or bicarbonate solution okay now if the map does not increase to greater
than 65 then you’re gonna probably have to start some vasopressors through a
central line and resuscitate this patient now looking at this haemoglobin
here I can see clearly that this is an elevated hemoglobin for somebody who is
so sick and this is probably showing chemo concentration here the low
platelets are probably a result of septic shock we could check that out by
looking at the pt/inr and PTT to see if they were elevated and also the
fibrinogen level if that was low this is the hematocrit it’s usually gonna be
three times that of the hemoglobin let’s look at the chemistry here we’ve got the
sodium and the potassium the chloride the bicarbonate the B UN and the
creatinine and then we have the glucose so the first thing that you want to look
at is the sodium and the potassium here I can see that the sodium is elevated
that usually means that there’s some amount of dehydration which goes along
with what we’re seeing here already this very high white blood cell count by the
way is usually indicative of just a few things and specifically because we’re
dealing with sigmoid a colonic wall thickening the big thing that you have
to think about there is c-diff c-diff colitis and there are only a few
antibiotics that can treat that also with relation to the history of
antibiotics in the past that also puts it together so why would the patient
have a low potassium because the patient has diarrhea and that’s going to get rid
of a lot of potassium it’s also going to get rid of some water and volume that
could be the reason why the patient is hyponatremic or on the border of being
hyper neat reaming clearly here the patient has a low bicarbonate which is
indicative of a metabolic acidosis and whenever you consider or entertain the
possibility that the patient has a metabolic acidosis you need to calculate
the anion gap so we add here 150 into 13 and we come up to 128 and 128 from 145
is an anion gap of 18 so that’s an elevated anion gap what could that be
from well I can tell you that the patient had a lactic acid level of
approximately 5 and that could explain why the patient’s lactic acid level and
anion gap therefore is elevated but if we add the lactic acid level to the
bicarbonate and say okay let’s say that the lactic acid went away and went to
normal this would only raise our bicarb to that of 18 which means that it’s well
still below 24 which is where it should be and that means that we have a non
anion gap metabolic acidosis as well which is probably related to the
diarrhea so I think what we have here based in the labs and the radiographic
findings and the vital signs is somebody clearly in septic shock from seed of
colitis who is very dehydrated he needs brisk resuscitation you want to avoid
normal saline I think in this case because that’s simple
exacerbate your non anion gap metabolic acidosis so giving some sort of lactated
ringers or bicarbonate it’s going to be probably advisable that’s going to help
your resuscitative events it’s probably going to help out with your kidney
function you’re gonna have to make sure with that resuscitative efforts that
you’re aggressively replacing potassium because the potassium is only going to
fall once you correct the acidosis and you resuscitate the patient correctly
now a lot of these things that we’ve just discussed about if you are
completely lost here there are a number of lectures that I want to direct your
attention to many of which are on our med cram a channel at YouTube but also I
want to direct you to med cram comm and we actually have a new series which gets
into the idea of understanding what a CBC can tell you and all the different
possibilities so look for that also we have a series on vasopressors that talks
about which vasopressor you would want to add and also regarding interpretation
of chest x-rays in addition we also talk about septic shock and that’s clearly
something that this patient has so we also talk about tackling every single
type of acid based disorder in our acid base series where we talk about laughing
acidosis we talk about figuring out the anion gap and how to calculate all of
the different types of acid based disorders that you can have in a patient
well with that thank you for joining us you

7 thoughts on “Complete Blood Count (CBC) Case – Lab Results Interpretation: Thrombocytopenia & Leukocytosis

  1. Thanks for watching! See the rest of this mini-course on CBC results at

  2. You are an amazing Dr. Thank you for taking the time to teach and for this and every other lecture. I am very thankful that I had very strict professors. I am an RN and I was not lost !

    Thank you again.

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