Peritoneal Dialysis (PD)

All right. So in this lesson I want to talk about peritoneal dialysis, sometimes abbreviated PD. So dialysis as a whole is always intended to replace or supplement the functions of the kidneys. And we do that with a semipermeable membrane. Well, in this case in peritoneal dialysis, the filter or the semipermeable membrane that we use is actually the peritoneal membrane, are the peritoneum. So what we do is instill fluid into the abdominal cavity or the peritoneal cavity. We let it sit, we let that process occur across the peritoneal membrane and then we pull the fluid back out. So the big benefits of PD is it can be done at home, it can be done on the go, and it's way less restrictive in terms of activity, it's less restrictive in terms of diet, and it's just a little bit more convenient. So there's a couple of different reasons why patients would want to choose this or why healthcare providers would choose this for their patients. One of the biggest ones truly is vascular access failure. If we cannot get a fistula, if we can't get a graft, if we can't safely insert a catheter or if they can't have a catheter for the long term, choosing to do peritoneal dialysis is the next best thing. If we can't get vascular access or maybe the patient is not tolerating hemodialysis - remember hemodialysis, we pull off lots and lots of fluid. Now there's a specific lesson on haemodialysis so check that out, but what you see is that we pull off two to four liters of fluid in about two to four hours. So we're taking a ton of fluid out of their system. And that can actually cause a lot of problems just hemodynamically. So if they're not tolerating that, we can do PD. If they have congestive heart failure, again, there's just a less fluid exchange happening. Might be a patient preference. Like I said, maybe they have that active lifestyle. This is something that can be done at home. They can do it when they're traveling, things like that. They don't have to worry about making appointments or maybe they have needle phobias. Really. It's just could be a patient preference. Maybe you've got somebody in a rural area and they just can't get to a dialysis center. They can't get to a facility to do appointments. This might be good for them. And then it's also great for pediatric patients. If you've ever tried to get a four year old to sit still for the four hours it takes to do a dialysis exchange, it's crazy. So doingPD or peritoneal dialysis is really a great option for those pediatric patients. They don't have to sit still for four hours. So one thing I want you to understand is that all forms of dialysis will use something called dialysate or dialysate fluid. What it is, is we say, okay, here's our, semipermeable membrane and we're going to run the patient's blood through on one side. And on the other side of that semipermeable membrane is our dialysate solution. And it's isotonic. It's almost identical to normal blood plasma. Well, remember, if you have somebody in kidney failure, what's in their blood is not what it should be. Right? So really what we're trying to do is get them closer to normal. And so the whole purpose of this dialysate fluid is to create a concentration gradient. So we're gonna have a certain concentration of a potassium, we're gonna have a certain concentration of bicarb, a certain concentration of glucose and all your other electrolytes and fluid, and it's going to cause certain things to jump over this way. Certain things to jump over this way into the patient's blood, and it's going to have the goal of normalizing the patient's blood. Again, if their kidneys are not working properly, they're probably going to have a super high potassium there who are gonna have a low bicarb. They might have trouble regulating their sugars and their fluids. So in dialysate we're usually going to see a lower concentration of potassium. Again, things move on a gradient, right? If potassium is lower in the dialysate then the potassium's going to move out of the patient's blood and into that fluid allowing us to get rid of it. Vice versa. With bicarb, usually it's higher. So we'll see bicarb moving into the patient as opposed to out. And then glucose. The big thing to just know is if you have a diabetic patient, make sure you know what the concentration of glucose is in that dialysate. So we're not, making their sugars go too high or too low. But basically just know the purpose of dialysate is to create a concentration gradient to be able to try to normalize this patient's blood. There's a couple of different types of peritoneal dialysis. Don't get too hung up on this, but what I want you to see is you can have ambulatory, which is where the patient will have a catheter. So here's my patient, pardon my horrific drawing. here's my patient and they will have a catheter in their abdomen. And so we will instill the fluid into their abdomen. And then we'll close up the catheter and they'll just let the fluids well or sit there for a certain amount of time. And then when they're done, they'll connect another bag, they'll drop that bag down and they'll let the fluid drain are removed by gravity. So this is great for somebody with a super active lifestyle because they can just put the fluid in, go about their day, take the fluid out, go about their day, put the fluid in and go about their day, et cetera. So it's going to have a set amount of time and a set number of exchanges per day. So an exchange is the number of times you put fluid in and then take that fluid out. So, this set amount of time in the set number of exchanges will be discussed with their nephrologist, but it's really great for somebody with a more active lifestyle. Then there's also cycler assisted peritoneal dialysis, which is when they use a cycle. So instead of just instilling the fluid, closing it up and letting it drain, they actually will put it on a pump. So they'll put it on a pump and that pump will continuously cycle that fluid in and out of their abdomen for a certain period of time. And then they'll be good to go. So usually what patients will do is they'll cycle overnight and then they'll have their whole day. They can go about their day entirely. And then they'll do this machine assisted cycler assisted at night. So there's a lot of different options with PD. Again, a lot of this is patient preference and a lot of it is because it's more convenient. So just to recap, the process here is we infuse the fluid into the abdomen. We allow diffusion to occur. So we have fresh dialysate fluid in the abdomen, then diffusion occurs and we end up with waste. So the waste fluid a lot of times could be called effluent. So effluent is basically the fluid that's left over after the fusion has occurred. It is the waste, it's kind of like urine and then we will put that bag to gravity and drain it. So really we're just using that peritoneal membrane as the semipermeable membrane. So nursing considerations, really similar to any patient getting any kind of dialysis. But just know that even in an inpatient setting you can do PD. Just know that if they are inpatient for whatever reason, we're probably going to be monitoring their labs. You want to watch their blood pressure and watch their hearing output. These patients may or may not be anuric, just depends on the severity of their kidney failure. If they're outpatient and also if they're inpatient, they're going to be following up with their nephrologist. The nephrologist is going to monitor their situation, monitor their lab values, and that's when they're going to start to adjust maybe the total number of hours that the fluid dwells or the number of exchanges per day. So the nephrologist will take care of that. Big things to note. Again, they are going to have this catheter in their abdomen for these exchanges that hooks up to the bag and then they drain so that catheter of course can get infected. So we want to monitor this site of that catheter, but also because there's a catheter, there's an open a route for bacteria to get into the stomach, into the abdominal cavity, and you have a risk for peritonitis. This is one of the biggest risks for any client getting peritoneal dialysis. Signs of peritonitis - abdominal pain, distention, fever, nausea, vomiting or a cloudy effluent. So remember the effluent is the fluid that comes off afterwards and if it's cloudy or it looks like it has pus in it, that could be a sign of peritonitis, so really important. Pay close attention for that. So things we need to educate our patients on signs of peritonitis, especially if they're doing a lot of this stuff at home by themselves. They need to know what they're looking for. And then of course they need to know how to perform the exchange. There's a lot of education we can do inpatient before they go home. Make sure they know how to connect to the bag, how to clean the catheter how to take care of themselves and make sure that they're doing the PD appropriately. Proper diet. A lot of times these clients will be on um, high protein, high calorie, or at least sufficient proteins. Sufficient calorie, low phosphorus is a big thing. Low phos. But the restrictions as far as like fluid and sodium, it's a lot less restrictive because there's less fluid exchange happening in PD as there is in haemodialysis. And then medications, they need to know what medications to take and when they need to know if there's any timing issues when it comes to their exchanges. Okay. So priority nursing concepts for a patient with peritoneal dialysis, they're going to be fluid and electrolyte balance, acid base balance and elimination. All of those things are affected by the kidneys and so therefore they're affected in any patient getting peritoneal dialysis. So let's just recap our key points here. The purpose of PD is to use that peritoneal membrane as the filter for our dialysis and to replace the functions of our kidneys. Big benefits is it's convenient, it's less restrictive, it can be done at home and it can be done even while traveling. Remember that, that dialysate fluid, the purpose is to create that concentration gradient so that we can try to normalize the patient's blood. And then remember the big risks for peritoneal dialysis is peritonitis. So you're talking about pain, nausea, vomiting, abdominal distension. And then we might see cloudy effluent. That's the big one. All right. So I hope that was helpful for you guys to understand peritoneal dialysis specifically. Make sure that you go back and check out the lesson. Dialysis and other renal points has a lot of information about why we do dialysis. There's also a less than on hemodialysis, as well as continuous dialysis called continuous renal replacement therapy. So check those out. and check out all of the resources attached to this lesson as well. Now go out and be your best self today, guys. And as always, happy nursing.