Sepsis Labs: The 9 Values You MUST Know (NCLEX® Review)

Sepsis lab values can be some of the trickiest NCLEX questions because they test your critical thinking so much. It's not just about memorization, right? So in this video I'm going to walk you through the absolute must know NCLEX lab values for sepsis and the critical thinking behind them so that you can finally understand it, my friend. I also have some really fun memory tricks to help you remember these all for your exams. So hit that subscribe button and click the notification bell and let's dive in. So straight out of the gate here, okay? Your first major critical thinking point for sepsis is this. Most sepsis lab values, they're telling you of one or two things. Either there's an infection happening in the body or the organs aren't getting enough blood to function properly and work. So keep that in your back pocket as we go through each of these lab values. Now, we're going to cover a lot of ground in this video and these are all really, really important key points to know for your nursing school exams. So I've put all of this in my free sepsis study guide for you, so be sure to download that. The link is down below in the description for you to snag it. So here's what you need to know about sepsis right from the start. It happens when the body's immune response to an infection goes totally bonkers and this causes really three main problems. Really want you to remember. And here's a memory trick for you, vlc. So VLC stands for vasodilation, leaky capillaries and clotting. So there's that infection happening in the body and that's causing this lack of blood flow to the organs in the body. And I have a fun memory trick to help you remember these lab values as we go through them. All right, you can think clw, bpd, and I can remember this as can't live without blood pressure dude. And that's cultures, blood cultures, lactate level, white blood cells. So the white blood cell count, BUN and creatinine, those are kidney labs. We've got platelets and coagulation times and procalcitonin. Then we've got D dimer. Now let's walk through each one of these and I will give you the critical thinking behind why these lab values change and what the NCLEX really wants you to know. Let me know in the comments if this mnemonic the can't live without blood pressure dude is helpful for you. I'd love to get your feedback on this because I want to be as helpful as possible. So let me know if this is helpful for you. So the first one in our mnemonic is culture. So drying blood cultures, Blood cultures is probably the most important lab test in sepsis. This is a huge nclex point that you've got to know. You will definitely be tested on this. All right, Normally they should be negative, right? So no bacteria growing. But in sepsis they might be positive. So showing that specific bacteria causing that infection that's causing that sepsis infection. Right? But here is the critical thinking part that you've got to know. The NCLEX loves this one. You must, must, must, must draw blood cultures before giving antibiotics. So think of it like a crime scene here. You need to find out who the bad guys are before you can go ca. Right? So we need to draw those blood cultures first. Now key nclex point. If a question asks about the order of your interventions for sepsis, blood cultures come before those antibiotics every single time. So that's your principle. So here's a memory check for this. Think culture before killing, right? Always get cultures before antibiotics. Kill that bacteria. Now here's a nursing consideration for this. You'll typically draw two sets of blood cultures from two different sites to a increase the chance of really catching that bacteria. And if the patient has a central line, you'll draw one set from that central line and one set from that peripheral site. Now we have L. L is for lactate and lactate, this is like a speedometer for how well really the blood is getting to the tissues. This is such a big important concept for you to know for nursing school. So normally it's less than 1 to 2 millimoles per L, but here in sepsis it's 2 millimoles per liter or higher, which tells us that those organs, they're not getting enough oxygen. So a higher lactate level that equates to worse tissue perfusion for our patient. Now here's kind of the pathophysiology that you've got to know about this. All right? So when the organs aren't getting enough oxygen because of poor blood flow, poor perfusion from that VLC that we talked about earlier, the cells switch from normal way of making energy, which uses oxygen, to a backup method that doesn't use oxygen. But the problem is this backup method produces lactic acid, which is a waste product. Now here's a memory check. When cells can't get oxygen, they make lactic acid, which means the tissues lack good blood flow. Alright? So remember, lactic acid is when the tissues lack oxygen. So critical thinking point for you here, when we have decreasing lactate levels, that tells us that our treatments for sepsis, they're working, and blood flow is now improving. So we want to see those lactate levels coming down. Now, the W stands for white blood cells. Now, this one seems kind of obvious, right? When our patient has an infection, that means a high white blood cell count. But sepsis can be kind of tricky, and this is where the NCLEX will try to trip you up sometimes. Normally, there's about 4,000 to 10,000 cells per microliter, but in early sepsis, often elevated greater than 12,000. But then as sepsis progressive, it can also be low. With less than 4,000, this is actually a worsening sign. So here's the critical thinking behind this that will really save you on test day. If the white blood cell count is low in sepsis, it means that the body is so overwhelmed that it can't even produce enough of those white blood cells to really fight that infection. Now, this is called leukopenia, and it's associated with a worse prognosis for that sepsis patient. Now, here's an NCLEX key point for you. Don't assume a normal or low white blood cell count rules out sepsis. It might actually indicate that that sepsis is getting worse. So we want to take everything in context. We for that NCLEX question. Now, here's our nursing consideration for this. We want to always look at that white blood cell count in context with the other symptoms that the patient's having. Right? A low white blood cell count with other signs of sepsis is very concerning, and we need to pay attention to it. And now, the B stands for BUN and creatinine. Now, these are kidney labs. Now, these show us how the kidneys are functioning. The kidneys are often the first organ to suffer in sepsis because they need a lot of blood flow in order to function properly. Now, normal BUN is 7 to 20 milligrams per deciliter, and a normal creatinine is 0.6 to 1.2 milligrams per deciliter. But in sepsis, both of these are often elevated. And here's why this happens. With sepsis, the blood pressure drops, and that blood flow to the kidneys also drops because of all that. Right. That VLC we talked about, the vasodilation, the capillary leak, Right. Leaky blood blood vessels. And the kidneys can't filter waste products effectively. But BUN and creatinine those are waste products that the kidneys usually filter out. So when they build up in the blood, it tells us that the kidneys aren't working enough to get rid of those wastes. And so here's your critical thinking point. A rising bun. In creatinine and sepsis, it can indicate acute kidney injury, or aki, which is a sign that sepsis is progressing and affecting the organ function. So this is bad news, and we want to look out for it. So NCLEX key point here for you. There's a big number to know. For the NCLEX, 30ml of urine output per hour. That's the cutoff for kidney perfusion. So if the patient's urine output is less than 30 milliliters per hour, and especially, especially if they have an elevated BUN and creatinine level, that indicates kidney problems in sepsis. So that is a very, very important number to know. For the NCLEX, 30ml of urine output per hour. Now, the P stands for procalcitonin and platelet platelets or coagulation times. Now, procalcitonin, this is our bacterial infection alarm. And platelets tell us about clotting problems that are happening. So for procalcitonin, a normal level is less than 0.1 nanograms per milliliter. Now, in bacterial sepsis, though, this is significantly elevated, greater than 0.5 nanograms per milliliter. Procalcitonin is like a smoke detector, specifically for bacterial infections in the body. It rises really quickly when there's a serious bacterial infection or bacteria invasion, and it helps us decide whether to start antibiotics and immediately. So here's your NCLEX key point. PCT is especially useful to help us tell if this infection is bacterial versus a virus or another inflammatory condition. So if you see a high PCT on a test question, think bacterial sepsis. And then we've got platelets here and coagulation times. So remember that C in our VLC memory trick, right? That stands for clotting, and it affects these lab values super big time. Now, normal platelets are 150,000 to 450,000 platelets per microliter. A normal PT is 11 to 13 seconds and a normal APT is 25 to 35 seconds. But in sepsis, platelets are often low. PT and APTT are often longer. And here's what's happening with this, and this is so, so important to understand for your exams. Here's what's happening. The inflammatory response. In sepsis, it Causes the blood to form lots of tiny little clots. These are called micro thrombi throughout the body. Now, this uses up platelets and clotting factors, so there aren't enough left to form clots when the patient needs them. Now here's a memory check for you. Sepsis makes the blood clot crazy. It clots so much that it's running out of clotting supplies. And remember, sepsis steals platelets. All that clotting just uses them up. Now here's an NCLEX key point. Low platelets with prolonged clotting times in sepsis, that can indicate dic. That stands for disseminated intravascular coagulation. That's a serious complication that you've got to recognize. Now, I actually have a whole other video on DIC that you can check out if you need it. That's another huge topic that nursing exams and the NCLEX love to test you on. So it's really important to know. Now here's a nursing consideration for you. Watch for signs of bleeding. We're looking for petechiae, bruising, or bleeding from the IV sites, especially if platelets are low. So these patients, they need gentle handling. They are at risk for that bleeding. And then the D, it stands for D dimer. Now, you can think of the D dimer as really the clot breakdown detector. So a D dimer, if that's produced, clots break down. So it's elevated when there's a lot of clotting happening in the body. So a normal D dimer is less than 0.5 milligrams per liter. But in sepsis, it's often significantly elevated. So here's your critical thinking point. High D dimer levels in sepsis. It indicates that there's that widespread clotting happening and that breakdown happening throughout the body. So remember those micro thrombi clots that we were just talking about? Right. Those are building up and breaking down. So here's your memory trick for you. D dimer detects destruction. It shows that clot breakdown happening in the body. Now let's talk about some really important NCLEX key points that you've got to know for these lab values and what to look for. Now, these are really, really important principles to know for sepsis, but also, also really any time that these lab values are out of whack or out of balance. So if lactate is high, we want to focus on assessing the tissue perfusion. So we're checking capillary refill, skin color and temperature, and their mental status. So these patients, they might need something like fluid resuscitation, vasopressors, or other treatment to help keep their organs perfused. And then if the white blood cells are low, we want to be extra careful about infections, right? Infection, infection control. Now, these patients, they have compromised immune systems and they're at a high risk for additional secondary infections. And if BU1 and creatinine are elevated, we want to monitor their urine output, we want to watch their fluid balance, and we want to be careful about medications that can further damage their kidneys. And if platelets are low, we want to watch for bleeding, we want to use soft toothbrushes and avoid any unnecessary injections. And then we want to handle the patient really gently, gently, because they are at risk for that bleeding. And lab values is just one of the things we've got to know for sepsis. The other one really is the nursing interventions and the treatment for what to do for a patient with sepsis. And I actually have a super helpful mnemonic for you for that, to know the nursing interventions and the treatment that you'll have to do for a patient with sepsis for your nursing school exams. And I walk you through all of that in this next video here. So be sure to watch that one next. And don't forget to hit that subscribe button and click the notification bell. And as always, my friend, go become the nurse that God created only you to be. And I will see you over there in that next video.