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Septic shock: Diagnosis and treatment

Video transcript

- [Voiceover] To understand the labs of septic shock, let's first go ahead and recall what septic shock is. So really briefly, remember, septic shock is an infective material that you see in blood vessels. White blood cells amount a response to the septic material. In amounting a response, they release all these different immune molecules that can cause damage to blood vessels and increase blood vessel diameter, and the permeability of blood vessels, and so on and so forth. What's the first thing you think you would want to do in a patient who might have shock? Well first of all, we want to diagnose it, right? So what can we do to diagnose shock? Well we have a couple of lab tests that we can use. The first thing you want to do is check what's going on. A patient comes in who has fevers, chills, they're sweating, they're very flushed. You notice that their blood pressure is dropping. So you're thinking, maybe septic shock. So the first thing you want to do is, aside from checking their temperature and checking their vital signs, is you want to check maybe they have an infection in their blood. Maybe there's infective material in their blood. So you can do that by getting blood cultures. Because you want to grow out whatever is in the blood and see if it's a fungus or bacteria or a virus. So blood cultures will allow you to figure out what organism is in the bloodstream. Next, you should probably figure out how severe the shock is, and if it is in fact shock. Are the organs damaged? What's going on? You'll get values such as lactic acid or serum lactate. Serum lactate is important because it shows you tissue perfusion, when cells of the body are no longer getting oxygen. So these little orange boxes are cells. When these guys are not longer getting oxygen, they have to resort through another way to produce energy. That other way is anaerobic metabolism, metabolism without oxygen. A byproduct of that is lactate, or lactic acid. So measuring the levels of serum lactate will tell you just how oxygen-starved these cells are. Next, you can also get an ABG, or an arterial blood gas. That will tell you how much oxygen is in the blood. It will also tell you other things like the carbon dioxide, different blood gases. And then you'll get some other lab tests that are maybe organ specific. So, for example, you might want to get a BUN or a Creatinine. These are specific tests for the kidney. I'm only going to write down these tests for the kidney, but you might want to get the other tests for other organs as well. Now, the lab values for the kidney are especially important because if the kidneys are deprived from oxygen for just a little while, they can actually be damaged. So they're more readily injured by lack of oxygen. So these are good labs to get. Now, once all these labs are in the work, the next logical step is to immediately treat this patient. Treatment is associated with mortality. The sooner the patient is treated, the more likely it is that they will survive. So they'll have decreased mortality if they're treated more quickly. The treatment usually starts with just very broad spectrum antibiotics. Broad spectrum antibiotics. Now, why broad spectrum? Well, when you first treat sepsis, you'll have drawn a blood culture, but you won't have the results back yet. So you'll have to start with an antibiotic that can treat many different types of infections. Gram-positives, gram-negatives. Many different types of bacteria. If the patient does not really get better with broad-spectrum antibiotics, use of anti-fungals may also be indicated, because it could be a fungal infection. Usually you start here. Broad-spectrum antibiotics. Then you'll check the blood cultures afterwards. Once those cultures return, the patient can be switched to a more tailored antiobiotic therapy to provide an antibiotic or an antimicrobial that the organism is susceptible to. Now remember, not only is there an infection going on, but as a byproduct of this infection, the patient has a drop in blood pressure. So, treatment will also include IV fluids to restore blood pressure, as well as a medication called pressors. What pressors do is they help squeeze down blood vessels to allow an increase in systemic vascular resistance, or resistance of blood vessels, which helps restore the blood pressure as well. So, both of these will increase blood pressure. So treatment will likely take days to weeks. In the meantime, while the patient is recovering, what do you think the next logical step is? You know, the patient has been diagnosed with septic shock, they're being treated for it. So the next step is really to see how the progress of the patient is. What's the progress of the infection? To check the progress, you know, you might continue to get lactate, ABG, BUN and creatinine to monitor the patient, but you can also get other labs such as a CRP or an ESR. Now CRP stand for C-reactive protein and ESR stands for erythrocyte sedimentation rate. Really, the names of these are somewhat inconsequential. The main idea here is you can track inflammation. So these allow you to track inflammation. When a patient is first diagnosed with septic shock, these values are going to be very elevated. Possibly up around 100. Each of these. Just to give you an idea, the normal value of CRP should be less than one milligram per deciliter, and the normal ESR really depends on age. It will be probably below 20 or maybe 25 millimeters per hour. That's the units of ESR, erythrocyte sedimentation rate. So CRP and ESR, as I was saying, may be drastically elevated. So resolution of septic shock will show these values starting to go back down to normal, so searching for a down trend of these elevated lab values. So really that's it with septic shock. It all makes sense based off of what's going on. Infective material in the bloodstream. Let me make a couple final points. You'll always want to start with blood cultures before you do antibiotic therapy. This is very important so that the organism in the patient's bloodstream can be discovered. If broad-spectrum antibiotics are started before blood cultures are obtained, you know there will be antibiotics in the blood. So when a lab technician goes to culture it, those antibiotics might interfere with the growth of the blood cultures. So always blood cultures first, and then antibiotics. But also, another great thing to note is these should not be delayed. Because remember, delay in treatment can lead to increased mortality. And last of all, in many hospitals you might hear the term, two large bore IV lines for IV fluid treatment. Essentially, that's establishing two lines in either arm in which fluids can get to the patient. They'll be called large bore because they'll be very large in diameter. These tubes will have a very large diameter. This allows for IV fluid to get to the patient quicker so that blood pressure can be increased very quickly. So remember the steps. Diagnosis, treatment, and then tracking progression of septic shock.