[0:00]So one of my medical students recently asked me to go over the different types of dialysis, and this is kind of what we talked about. So the first thing that we have is intermittent hemodialysis. This is the most common one that you're going to see where people are, for example, getting their Monday, Wednesday, Friday outpatient dialysis or they're getting their Tuesday, Thursday, Saturday dialysis. And then you also have a SLED, which stands for sustained low efficiency daily dialysis. This is one that is run a little bit slower and we'll go over that in just a little bit. You also have CRRT, continuous renal replacement therapy. And also you have what's known as CSLED, continuous SLED. And almost another thing to talk about briefly is, you know, have peritoneal dialysis, which you can do as well. So in terms of the timing, it's nice to know how long each of these sessions kind of last. So intermittent hemodialysis is typically going to run like 3 to 4 hours, whereas SLED is going to be about 12 hours. CRRT is 24 hours. And then SLED is a CSLED is 12 hours times two, so basically running for 24 hours. Um, and then peritoneal dialysis, you're going to be able to do this at home. It's usually every night or so, although I don't have that much experience with peritoneal dialysis. But really the big point is, why do we, you know, transition patients from intermittent hemodialysis to SLED or CRRT? And the big thing that really comes up a lot is the hemodynamic effects of dialysis. So with intermittent hemodialysis, you're having much bigger volume shifts, and you're running the dialysis flow rates and the blood flow rates at much higher rates compared to these slower kinds of dialysis. And so it's going to have a much bigger association with hypotension. In contrast, these ones, CSLED, CRRT, and continuous SLED, are going to be associated with less hypotension because you're being a little bit more gentle with your dialysis. Now, the thing that we typically do is when people are requiring this, that usually means they're hemodynamically unstable. So typically patients who are on these kinds of dialysis are going to be in the ICU. And basically, they will need to be upgraded to the ICU in order to get these kinds of dialysis. Another key point here is that for SLED, CRRT, CSLED, you can't use a patient's fistula. So for the patients who are getting intermittent hemodialysis, you can use a fistula, but for these types, we typically don't use their fistula. We ask them to get a dialysis catheter instead.
[2:44]And the reason for this is, you know, if a patient is getting dialysis for 3 to 4 hours, they can get it through their fistula in their arm. But if somebody's getting it for 12 hours or 24 hours, you can't, you know, reliably have them keep their arm straight and not move it at all for 24 hours. Um, and you know, if they move it just a little bit, they could, you know, have the needle come out and they could exanguinate very quickly because it's a high, um, you know, high volume, high blood flow area with the AV fistula. So typically, we get the dialysis catheter because it's much more comfortable and, you know, they can still move around and not have that risk of exanguinating while they're getting this. Now, in terms of SLED, CRRT and CSLED, uh, it's kind of a progression, right? So this is going to be the most hemodynamically unstable patients, the CRRT, and then as they start to get a little bit more stable, you transition them to SLED, and this can be run anywhere from like 12 to 18 hours, it's not just 12 hours. And eventually, you get them back onto intermittent hemodialysis, at which point they can go back to the floor. In terms of some of the other differences, uh, you know, sometimes we do CSLED instead of, like, what's the difference between CRRT and CSLED? They're both running, basically, sorry, they're both running basically for 24 hours. Um, and basically, the CRRT, uh, is kind of like a fixed dialysate, uh, at least at Davis. Uh, whereas, uh, at, um, you know, with the CSLED, you can actually, uh, change the dialysate, and it's better, um, for treating electrolyte abnormalities. Okay, so it that leads us to the next discussion of, uh, how do, how does dialysis actually help with electrolyte abnormality? Say your patient is coming in with a potassium of six. How do we actually run it through the machine in order to get their potassium back to a more normal level, like four? So what you have is you have these baths, and this is something that, uh, I learned as a medical student, but it's very useful to know, uh, you know, how these machines actually work. So basically, if you have this dialysis machine here, you have these little baths that sit here. So you have your, your K bath, and you have your bicarb bath and various other baths here. And basically, the blood is going to be coming in, and it's going to be coming in through here, and it's going to exchange with the bath here. And so you can really titrate the bath based on what you want the potassium to be. So, for example, in this patient with a potassium of six, we could potentially give them a K bath of one. And that would give us a really nice gradient, uh, to try and get that, you know, potassium down to a regular value of four. And what I've learned is the magic number, uh, is seven. So magic number of seven. And that would correlate to, uh, trying to get the, the potassium in a good spot. So, if their potassium was two, for example, you give them a K bath of five, or potassium was five, you can give a K bath of two. And that will really help titrate it to the correct area. Uh, the other thing that I wanted to briefly mention is that there is this thing called, uh, I don't know what color to use at this point, but there is this thing called pure ultra filtration. So say a patient, um, just needs volume removal alone, then you can do what's called, uh, pure ultra filtration or puff. So pure ultra filtration. And this one is going to just be removing volume. And so, uh, sometimes it can be a little bit easier for them to tolerate, uh, and you can do that just if somebody has, you know, they're anuric and they need volume removal, but their electrolytes all look fine, you can do this pure ultra filtration. Now, typically learning point for medical students and one of the most common PIMP questions is what are the indications for dialysis? So indications, obviously, is going to be your A E I O U mnemonic. So that's going to be acidosis, and typically, I think of generally when the pH is starting to get pretty low, like pH less than 7 or so. Electrolytes, and what's the typical one that we look for here? That's going to be potassium, usually hyperkalemia. I is going to stand for intoxication, so different drugs, uh, and other things that need to be dialyzed out. A lot of times on the boards, it's going to be like a lithium overdose or lithium toxicity or other drugs in general. Uh, overload, so patient is no longer making urine, they're starting to get accumulation of fluid all over. That's going to be an indication for dialysis. And uremia. And I like to ask the medical students, you know, what is the point at which you would dialyze somebody for, um, uh, uremia? Uh, what's like the BUN level that you would expect? And typically, it's going to be a BUN greater than a hundred. So if somebody's BUN is 70 or 80, uh, they really probably don't need dialysis. And then there's also the counterpoint that some patients have BUNs of 120 and they're fine and they don't need dialysis. So you really have to look for uremic encephalopathy or symptoms of uremia. Uh, before you say this is an indication for dialysis, and typically, and typically, you're not really going to see a lot of those symptoms until the BUN is at least a hundred. So that's kind of my minimum threshold. Uh, a couple other things that I wanted to note about dialysis. Um, let's see if we get another color here. Uh, kind of running out of colors. So, um, there's a couple things to know, so we have this thing called dialysis disequilibrium syndrome. This is if somebody's getting dialysis for the very first time and you drop their BUN too quickly. This can cause all sorts of symptoms like headache and just like, basically they'll feel really, really bad and you can basically worsen some of their symptoms. Um, and so that that's this is again, this is when you are doing dialysis for the first time and you drop their BUN too quickly. So, typically, if somebody's starting dialysis for the very first time, you're either going to run it at a slower rate, or you're going to do it for less hours, so maybe like a two-hour session instead of a four-hour session. And you're not going to let the BUN drop quite as much, and that's going to help you avoid this dialysis disequilibrium syndrome. Uh, other things to think about, uh, there, you know, this this may be something that you would see is recirculation syndrome. So, uh, the classic way this might present is, you're doing dialysis on this person, and then every single time, the next day, you're checking all their electrolytes and stuff, and nothing looks better, uh, and it's like, wait, why is the dialysis not working? So a lot of times what can happen is, you have the fistula, and maybe there's a clot or there's something blocking it, and so the dialysis is just dialyzing fluid, and then it's going, you know, uh, to the heart a little bit, and then it gets blocked, and then it comes back. And then you're just dialyzing the same fluid over and over again, and the rest of the blood in their body is not getting dialyzed. So this would be called dialysis, this would be called recirculation syndrome, where your dialysis is not being effective. Another side effect of patients who are on dialysis that you should know about, this is very common that will come up on the boards, but if they start developing the, uh, you know, these black necrotic-looking lesions, uh, this would and you're you're going to classically see this on the boards. There's a very common board question, they'll just show you a picture of their skin, there's just like necrotic scar-looking kind of stuff, basically. And this is calciphylaxis. Basically, I I believe it's deposition of calcium in the blood vessels which causes this appearance. And there's a lot of specific treatments you can do for this as well. All right, just zooming out a little bit, um, so I can keep this here, and let's see if I can move this. So, a couple things, uh, when you, when a patient comes in and they have ESRD and they need dialysis, you know, you're usually going to consult nephrology, right? Um, because they're going to help manage this. And there's a couple things that they will do, uh, when, you know, you consult them, so consult nephrology. And a couple things that you may typically or very frequently see patients on, uh, they're going to be treating their anemia. Because these patients have anemia of chronic renal disease, uh, they're going to treat their, um, high phos, uh, and, you know, high phos, low calcium, things like that. And basically, all of this is called, uh, CKD mineral bone disease. Uh, other things that they look at, they'll look at the patient's acid-base status, they'll look at their volume status, uh, hypertension, and also their electrolytes. So, just briefly talking about, uh, the anemia. So, in this case, uh, we want to make sure that the patient, a lot of these patients typically get anemic over time. And, uh, you want to know the indications for iron replacement. So, first of all, um, usually their hemoglobin goal is greater than 10 to maybe like 11 or so. Uh, and they will often use erythropoietin stimulating agents, like EPOetin. Uh, but before you do erythropoietin stimulating agents, you want to make sure they have iron replacement first. So typically, they have a higher threshold for replacing iron compared to a typical iron deficiency anemia. So, usually, you want to make sure ferritin less than 500, uh, transferrin saturation less than 30%, and hemoglobin less than 10. And then you should, uh, if this is the case, then you should give IV iron. And try and replace their their stores. Once the stores are adequately replaced, and if they're still anemic, then you'll start the erythropoietin or the EPOetin at that point. Uh, the CKD mineral bone disease, you're going to see them using a lot of phosphate binders, um, like uh, sevelamer and, uh, lanthanum. And, uh, basically, you really want to treat the phos if it's, you know, greater than 5.5. So phos greater than 5.5 has been associated with increased mortality, so that's when you're really going to want to push, uh, using some of these, uh, agents. But you also want to check their calcium levels, their PTH levels, and vitamin D levels pretty frequently because all of these things can contribute to mineral bone disease, and you want to treat it, uh, over time. So, remember with the PTH, you get this secondary hyperparathyroidism. And then, uh, the vitamin D levels could be low, so you can replace that with ergocalciferol or cholecalciferol. And then treatments for high PTH. You So, usually, you treat the phosphate first, um, but if you needed to treat this, then we use things like calcitriol and cinacalcet. One last thing that I did want to talk about is, uh, this thing called FGF23. This is something that does show up on the boards sometimes. So, this is basically a a molecule that helps excrete, so it helps excrete phosphate. And it's actually associated with CKD, uh, and mineral bone disease. So, you will sometimes see this on your board exam questions. Um, you know, they'll ask you, uh, why is this patient's phosphate high, and, you know, what's a marker for increased CKD severity? And, uh, if you say, you know, basically low FGF23 is associated with worsening CKD or, you know, more severe CKD. Okay, and that is a common board question that you may be asked. So, hopefully this was helpful going briefly over the different types of dialysis, indications for dialysis, and some of the slight, you know, modifications that you might need to do when managing patients on these different types of dialysis. Thanks again for watching. I'll see you in the next video and peace.
