02.05 Hemodialysis (Renal Dialysis)

All right, in this lesson we're going to talk about hemodialysis, sometimes called renal dialysis or just dialysis. So what is hemodialysis? Well, this is when we remove the blood from the patient. We filter it with a machine. You can see the machine here and then we return the blood to the body. So essentially we pull blood off the patient, cycle through the machine, through a filter, and then we return that filtered blood back to the patient and then we pull off a large amount of fluid typically, and we call that effluent. So hemodialysis specifically has to be performed via some sort of vascular access. So we've got to have access into the bloodstream. This can be done with a fistula or a graft or a permacath or some other kind of catheter. If you want more details on vascular access, check out the lesson called dialysis and other renal points. I talk in detail about vascular access and how to understand the different types. The biggest purpose and benefits of hemodialysis is to replace the functions of the kidneys. That is the purpose of dialysis. We're going to filter the toxins out, regulate electrolytes, and a lot of times we can remove quite a bit of fluid. In fact, sometimes in dialysis we could remove two to four liters of fluid in between two and four hours, just depending on the client and what the goals are. So it's quite a bit of fluid removed off of this patient, especially if they're in volume overload. So indications for hemodialysis, some sort of kidney failure. Okay. Some sort of kidney failure. This could be acute kidney injury, could be chronic kidney disease, right? But here's the thing. You could have clients who have kidney failure, but with medications, with fluid, you can kind of manage them, right? So we don't go to dialysis until there's a significant problem. So acute kidney injury with severe fluid overload with refractory hypertension, uncontrolled hyperkalemia, or other symptoms, severe acidosis or really super high bun. So we don't just go straight to dialysis. When they start to get complicated, that's when we go. Same thing with chronic. If maybe they've developed pericarditis, maybe they've got severe fluid overload or pulmonary edema, refractory hypertension, maybe they've developed a uremic encephalopathy uremic meaning they have lots and lots of this urea nitrogen in their blood system. Or maybe that uremia has also caused some bleeding issues. So again, we want to try to hold off on doing dialysis until we have complications. If we've got complicated kidney failure or accelerated kidney failure, that's where we move towards dialysis. So I just want to give you a quick overview of kind of what dialysis looks like. So first we're gonna pull the blood off from the patient. We're going to run it through a pump. Sometimes at this point we're actually gonna add some sort of anticoagulation. Could be Heparin, could be citrate. The purpose of this is to actually prevent clots in the filter. Typically, we're not actually anticoagulating the patient themselves. So then the blood's going to come in through the filter and in the filter we have dialysate and that dialysate is going to allow significant amounts of diffusion to happen. So we have diffusion here happening inside the filter and then that dialysate is going to come off and into a collecting container. So this is our used dialysate so this is dialysate after diffusion. So after we've pulled all of the waste products and things off of the patient, that is our used dialysate also called effluent. So then once we've filtered the blood and we've allowed the fusion to happen, that filtered blood goes and gets returned cleaned to the patient and you'll see things here like the arterial pressure monitor, venous pressure monitor, air trap. So obviously if we get air bubbles from the filter, we don't want to return that to the patient. So we make sure we trap that air before we send it back to the patient. So then we send the blood back in and it's filtered and that will just continue to cycle until we've pulled off the amount of fluid we want to pull off or we've achieved the goals or a certain timeline just depending on what's ordered. So just want to make sure you guys really understand dialysate. Again, dialysate is the fluid that's actually put into the filter. So here's our little filter. We've got a semipermeable membrane, we've got the patient's blood coming in this way, and we've got dialysate coming in this way. And so what's going to happen is we're going to create a concentration gradient. So we've got certain concentrations of various things and certain concentrations of fluid in the dialysate. It's going to cause some things to come out of the patient into that fluid and some things to come out of the fluid and into the patient. And so we're looking at certain concentrations and things like potassium, bicarb, glucose - just depends on what the patient needs. It's going to be kind of tailored to the patient. But usually kidney failure patients have a high potassium and a low bicarb. So in the dialysate we're going to see a lower potassium that allows potassium to come off of the patient and usually we're going to see a higher bicarb that allows bicarb to be replaced into the patient. Again, it's all about this concentration gradient. This dialysate is almost identical to normal blood plasma. It's ISO tonic. Really, we're just trying to normalize what their blood is doing. We're trying to fix the problem. So concentration gradient established by dialysate fluid and that's how we kind of replaced the functions of the kidneys. So nursing considerations for hemodialysis, it's really important that you know your patient's schedule. Typically you're going to see something like three days a week. On most patients you might have like Monday, Wednesday, Friday, or they might be a Tuesday, Thursday, Saturday. So it's really important to know their schedule. I have had patients come into the emergency department on a Thursday and they'll say, well, I was supposed to get dialysis yesterday, but I didn't feel good so I didn't go. And I'm like, okay, maybe you didn't feel good because you needed dialysis? So then they show up on Thursday and their bun is through the roof, their potassium's through the roof. They feel horrific, they're super volume overloaded. And so it's really important not only to know what their schedule is, know if they're on track, and when they need their next dialysis, but also to kind of consider maybe they missed one. Maybe that's what's going on with them. So make sure you know that. As far as monitoring, we're gonna monitor pressures within the catheter or within the access because we want to make sure we're um, things are moving fast enough that we're not clotting, but also that we're not getting kinked or disconnected. Monitoring vital signs, really important, especially blood pressure, especially if we're pulling off a lot of fluid, we can see a lot of hypotension. So really important to monitor that. We're going to monitor their labs. Um, we're gonna monitor their electrolytes and we're also going to monitor things like their bun and creatinine. And so their actual waste products that are supposed to be being removed. And then of course we're going to monitor their intake and output if they're volume overloaded, we're trying to pull fluid. We've got to know what we've actually accomplished. A strict intake and output with your dialysis patients. Vascular access, if you've watched the lesson called dialysis and other renal points, I talk in detail about vascular access. This is their lifeline. You have got to protect their accents, whether it's a graft or a fistula or maybe they have a catheter. Either way you've got to protect it and evaluate it, assess it. And then lastly is medications. What should be held? What should be given? A lot of medications can actually be dialyzed off. So if we give it and then we immediately send them to dialysis, then that medication has no effect cause it's going to get pulled right off. So make sure that you know what they need. Talk to the doctor about what needs to be held before dialysis. So patient education is actually really similar to our nursing considerations. Make sure that they know their schedule. But the other thing is make sure that they know how they're going to get to their appointments. I cannot tell you how many patients I have had missed dialysis because they couldn't get a ride. So make sure you know, if you need to work with a social worker to help them have transportation to their appointments. It's really important medications. Again, what to take, what not to take, what their schedule is. Make sure that they know a lot of times they're going to be on things like a phosphate binder called FOS lo, so make sure they know that they need to take that before meals. So all their medication education, dietary restrictions, again, hemodialysis is a little bit more restrictive than something like peritoneal dialysis. They still need to be on a high protein, high calorie diet or at least sufficient protein, but they're also going to need to be on low sodium, low phosphorous, and usually a fluid restriction, especially if they experience a lot of volume overload. And then again, vascular access care. These patients need to know what to look for, how to take care of their vascular access, how to know if something's going wrong with their vascular access. It is literally their lifeline. Patients that are on hemodialysis are typically on it because their kidneys do not work. And so if we lose their access, we lose their ability to get dialysis and it's a huge, huge problem. So priority nursing concepts for a patient with hemodialysis are going to be fluid and electrolyte balance, acid base balance and elimination. These are priority things that are affected in a client with kidney failure. So they're going to be the priority things affected for a client getting hemodialysis. Okay, let's do a quick recap. So hemodialysis is when you have an external machine that is replacing the function of the kidneys. So this could be for acute kidney failure or chronic kidney failure. So acute, this could be a temporary situation, or if it's chronic kidney disease, you're going to see them getting us permanently on a regular schedule Monday, Wednesday, Friday, Tuesday, Thursday, Saturday. Just remember that typically we're looking at some sort of complicated or complex kidney failure. Usually we don't go the moment that they're in some kind of kidney failure. But if they're developing severe volume overload, refractory hypertension, refractory hyperkalemia, that's gonna be a problem. It's going to require dialysis nursing considerations. Make sure you know their volume status. They're in, taken out, put, watch their labs, protect their vascular access and know what meds they need. And the biggest thing to know with patient education, besides those things, is their schedule. Make sure they can get to their appointments. It's so important. All right? So those are the basics of hemodialysis. You know, if you do end up going to work on a dialysis unit or work with patients that are receiving dialysis, you'll learn so, so much more about details about how to choose dialysate fluid, how the nephrologists calculates those things. But for now, these are the basics you need to know for any patient getting hemodialysis and I'll go out and be your best self today. And as always, happy nursing.