Lab Values, part 23: Bilirubin

Hi, I'm Meris, and in this video, I'm going to be talking to you about the lab value bilirubin. Let's go ahead and get started.

All right. So first up, let's talk about what bilirubin is. Bilirubin is a substance that is created when red blood cells are broken down. So this is going to be part of our normal process of being alive, right? We are always breaking down red blood cells that are old and worn out or dysfunctional. So we will always have some variety of bilirubin sort of just hanging out in our system. But it's found in bile as well. And it is the thing that gives bile that characteristic yellow color to it, okay? So bilirubin, again, it's super important for us to help break down fatty foods. It's going to be produced by the liver for-- I'm sorry, the bile is produced by the liver, but the bilirubin is a component of it. And so we don't expect that you're going to have no bilirubin in your body, right? We expect that you will have some. So the expected range here is going to be 0.3 to 1 milligram per deciliter. So this is a small amount, but I do want to break it down slightly further for you.

So we do have two additional values that go in here. And again, the total bilirubin, that big number, that's the one that I would really focus on. But there are two others. We can talk about the direct or conjugated bilirubin and the indirect or unconjugated. Direct conjugated bilirubin is going to be the bilirubin that is just kind of free-floating around. It's not bound to anything, and it's just free in our body. Whereas this indirect or unconjugated bilirubin, this is bilirubin that has been bound to albumin. So albumin is kind of carting it around. So it is not kind of just free-floating around. It is what we call indirect or unconjugated. So when we talk about direct conjugated bilirubin, this is going to be 0.1 to 0.3 milligrams per deciliter. That's going to be the smaller amount of it. And then for the indirect or unconjugated, that's going to be 0.2 to 0.8 milligrams per deciliter. Again, we expect most of it is going to be bound up with albumin. These two things put together give us that total bilirubin range there. And we do have a cool chicken hint here to help you remember that total bilirubin number, which is that Billy will only pay up to $1 for his Reuben sandwich. I don't think he's going to be getting a very good Reuben if he's only willing to pay a dollar for it, but that is our way of remembering this.

So now if it's elevated, you will probably notice this in your patient pretty quickly because they will experience an alteration in their skin color known as jaundice. Again, remember, bilirubin, it's yellow in color. It's what gives bile its yellow color. It's also what gives urine its characteristic yellow color because it is being filtered out and excreted by the body, by the kidneys. So we do know that if you build up too much bilirubin in your system, in your bloodstream, you're going to see that yellow discoloration to the skin known as jaundice. And just a reminder that just because your patient does not have white or fair-toned skin does not mean that you get to gloss over a skin color alteration. You need to become adept at finding alterations in skin color in your patients with black and brown skin. You must, or else you are not living up to your potential as a nurse, and you are failing some of your patients.

So remember, in somebody like me, it would be very obvious that I'm jaundiced pretty quickly. I'm going to turn yellow. But in somebody with darker skin tone, you need to be assessing for things such as the mucous membranes in the mouth and around the eyes. The eyeballs will turn yellow in color too. And you can see these alterations elsewhere. Be sure to be looking at the palms and the soles too. Look at nail beds. Look anywhere you can. But again, we are not missing this alteration because our patient is not white or fair-toned, okay? We are going to catch it because we're going to have excellent assessment skills. Go watch the health assessment video I did on alterations in skin color if you would like some more resources.

Now, what if it's elevated, and I see my patient is jaundiced, and I'm thinking, "Uh-oh, something's not right. What's going on here?" Well, some possible causes include liver dysfunction. That's going to be the number one cause because this is a substance that is produced by the liver too. So if something's going wrong with the liver, do we have this bilirubin backing up into our bloodstream and we have this elevation in that number? Bile duct obstruction. Again, if I can't get the bile out, then I'm not able to use that bilirubin normally and appropriately. Hemolytic or pernicious anemia doesn't make sense, right? You're thinking, "What does that have to do with anything?"

Again, remember that bilirubin is also produced when red blood cells are destroyed. So if I have hemolytic, in particular, or pernicious anemia, where I have these red blood cells that are going to get destroyed and they're going to be chewed up by my spleen, then I need to keep an eye out for this. So anybody I am giving blood to, I need to be on the lookout for those transfusion reactions. And anybody with jaundice, I can't rule out that they are having some form of anemia too. Transfusion reaction, which I kind of throw in with hemolytic anemia, and then Gilbert's syndrome as well. There are a lot of things that can lead to elevated bilirubin levels. So again, this is just something where we're giving you the key players here, the big shots of why it could be elevated, but just keep in mind that there's a lot of things going on. Any liver dysfunction can elevate that bilirubin. It can be elevated in newborns and neonates. There's so much going into that. But what you need to know is that a number over one requires additional investigation.

All right. I'm so glad you stayed until the end because I'm going to test your knowledge of key facts provided in this video with some quiz questions.

Which form of bilirubin is bound to albumin in the bloodstream?

Unconjugated or indirect bilirubin.

What is the name of the alteration in skin color associated with elevated bilirubin levels?

Jaundice.

All right. That is it for this video. I do hope you learned something. I'll see you in the next one. Thanks so much, and happy studying.