03.04 White Blood Cells (WBC)

In this lesson we're going to talk about white blood cells

Just a heads up, this lesson is going to be pretty in-depth and maybe a little bit longer than some of the other ones that you've seen, but all of these values are really important so hang tight.

When we talk about white blood cells, we're looking at the immune system. And when we look at this lab, what we're looking at is a normal white blood cell count of 4,500 to 10,000 cells per microliter. That is a normal value. Now what we've done is we've broken up all these white blood cells. White blood cells are not a one-size-fits-all, and they all have different purposes, and we're going to go into that here in a little bit. But these are the normal values for all of the ones that we're going to talk about.

Now all of these white blood cells fall into what we call a differential, meaning that they differentiate all of the cells between each other. And these volumes are all broken up into percentages meaning that all of the cells account for a certain percentage of the total volume of the white blood cells. So to clarify this let's look at neutrophils. Neutrophils take of 40 to 60% of a normal count of the white blood cells. Then you have these things called bands which account for 3 to 5%. These are essentially young neutrophils, and they can signal an infection or inflammation if they're greater than 8% of the total differential value.

Eosinophils take up 1 to 4%, basophils are 0.5 to 1%, lymphocytes are 20 to 40%, and monocytes are two to 8% of the total amount of white blood cells.

So let's break this down a little bit further, so that when you see a differential for your patient, you know exactly what we're talkin about.

Now remember white blood cells are the cells in the body that are responsible for responding to infection, inflammation, they are the the front lines for your patients immunity. The made in the bone marrow, and they are responsible for taking care of all the viruses and bacteria and potential pathogens that come in and they break them down. For things like a vaccinations, what you do is you stimulate an immune response by creating antibodies which is your immunity. Now when you have a foreign pathogen, like bacteria, it triggers a response called phagocytosis which is literally phago meaning eating and cytosis pertaining to cells. So some of the white blood cells come in and are responsible for recognizing foreign Invaders so that they actually have an immune response, and then there's also the cells that go and break all of pathogens down. Now let's get to the specifics of white blood cells.

So let's talk about the different types of white blood cells that you're going to see on a differential and what they mean.

Let's start with neutrophils. Neutrophils are produced in response to inflammation. Even though they normally take up that 40 to 60% of your white blood cells, they will go up if there's an inflammatory response. The next one you're going to see is bands. Bands are a type of immature neutrophil and they're normally in that three to 5% range, but if there is an infection or if there's some inflammation, you're going to see you over production by the bone marrow as a response to inflammation or infection and that goes up to greater than 8%. The thing that you need to recognize is that this is called a left shift, so if you hear there's a left shift in the bands in the differential, What that means is that there's an overall stimulation by the immune system to produce more neutrophils for some sort of infection or inflammation.

Eosinophils and basophils are white blood cells that respond specifically to inflammation. There are much smaller numbers, and you're going to see using to fill overproduction when you have some sort of parasitic response. So if there's some sort of parasite or other pathogen that triggers an eosinophilic response that is going to cause that number to go up on your differential. The same thing with basophils, being that you'll have an increase in basophils production in response to inflammation, particularly with some sort of allergic or asthmatic response. So if your patient has some sort of anaphylactic reaction, or they're having an asthma attack, you may see an increase in the basophils in their CBC differential.

When we think of white blood cells, we often think of the lymphocytes. There are several different types of lymphocytes, but they have several different specific functions. One of their main jobs is to respond to foreign pathogen, so think vaccines. You introduce the antigen or the vaccine, and the lymphocytes respond by recognize it and then they create these things called antibodies. Let's use the flu vaccine as an example. People get the flu vaccine, and if they're exposed to the flu, they've already created those antibodies and that's what protects them. Lymphocytes are broken up into several different types of helper cells, called t cells, B cells, and natural killer cells. Their job is to go out and destroy foreign pathogens. The other thing about your lymphocytes on your differential is that they can sometimes indicate things like lymphoma or even leukemia.

The last one that you're going to see on your differential is going to be your monocytes. Those are your macrophages or your white blood cells that go out and eat you're pathogens. Their job is to engulf and destroy foreign Invaders. If you see a monocyte elevation on your white blood cell count, then that could be indicative of some sort of infection.

So what are some special consideration that you have to think about when you're getting your blood samples? Well you're going to submit your CBC for your white blood cell count in a lavender top tube with EDTA in it. Very commonly, it's going to be submitted with your entire CBC, which is also going to give you things like your red blood cell count, hemoglobin, hematocrit, and platelets. The biggest thing is that the differential is going to give you all of the breakdown of those numbers. So do you think that your patient needs a differential, talk to your provider and have them order that. It's not always a standard order, so just make sure that you let them know.

Like we talked about in the differential patho, this is where you're going to start to see elevated white blood cells and decreased white blood cells. And it's also really important to pay attention to the differential.

Elevated white blood cell counts are called leukocytosis, and you're going to see things like infection inflammation, you'll see trauma or stress, or even pregnancy. All of these things will cause an increase in the white blood cells. Typically you're going to see this in either your neutrophils and possibly your lymphocytes, but you need to pay attention to all of the levels in the differential. Like we talked about with asthma or allergic reactions, you're going to see increases in those eosinophils and in the basophils, and probably in the neutrophils. But it's really important to pay attention to the entire differential as a whole, and also to look at your patient and see what's going on with them.

When you have a decrease in a white blood cell count, that's called leukopenia. You're going to see leukopenia with several different conditions especially your autoimmune diseases. So something like systemic lupus erythematosus, which we also call SLE or rheumatoid arthritis. You also see decreases in your white blood cells with certain types of cancers, so think leukemia or lymphoma. Also you'll see decreases in your white blood cell count if your patients undergoing chemotherapy or radiation, and some medications can even cause decrease in your white blood cell count.

One thing that I want you to be mindful of is if you notice that your patient has abnormally low white blood cells, you might see them go under what's called neutropenia precautions. What this means essentially is that your patient has no ability to fight off any sort of infection. When you are I get the common cold, our immune system automatically kicks in and does its job. But with patients that don't have any sort of immune response because all their white blood cells are gone, they can't fight off those infections. So what do you do? Well you do things like play some mask on the patient or put a mask on yourself. You don't want to breathe on them or cough on them. Make sure you wash your hands, make sure you're using gloves, sometimes you even have to gown up depending on what's going on. Find out what your facilities specific policy is when you have neutropenic precautions, but the thing you need to know is that neutropenia precautions tell you that your patient has no immune response and that you have to be the advocate to protect them.

Our nursing concepts for this lesson include lab values and infection control, because we're looking at white blood cell counts.

Alright so let's recap.

Your white blood cell count normal value is going to be 4500 to 10000 cells per microliter.

Always pay attention to your white blood cell count differential cuz it's going to tell you what's going on with your patient.

When you have elevated white blood cell counts think infection, inflammation, asthma, or even some sort of allergic response.

When you have decreased white blood cell count you need to understand that your patient also has no ability to fight off infection, so this could be due to autoimmune disease, cancer, medications are the therapies.

When you hear neutropenia precautions, do what you need to do to protect your patient. They can't help themselves at this point, so you need to be their advocate.

I know that was a lot to unload, but it's really important that we went through all of it so thanks for hanging in there.Make sure you check out all the resources attached to this lesson. Now, go out and be your best selves today. And, as always, happy nursing!!