Following up from our article on Dialysis Essentials , we present below, a comprehensive insight on one of the preferred types of Dialysis in kidney failure – Peritoneal dialysis.
Find the Table of Contents below. Click on your topic of interest to go to the section directly or scroll down to read the full article (recommended!).
TABLE OF CONTENTS
What is Peritoneal Dialysis (PD)?
Peritoneal Dialysis or PD is a treatment option for patients with excess buildup of metabolic waste products or toxins in their bloodstream. This modality can help when normal body mechanisms to clear the waste-load of our blood fail to do so, by themselves.
The word “Peritoneal” here refers to “anything associated with the Peritoneum“. And Peritoneum is the technical name for the thin, double-layered tissue-sheet with a rich blood supply that covers (wraps around) our intestines & some other organs in our abdomen (belly).
Take a look at the image below & read the caption to get an idea.
Any medical condition that affects the normal body waste-clearing mechanism in our body by Kidneys & Intestines either directly or indirectly results in the levels of unwanted blood wastes to go haywire. Dialysis can be an option to treat most such conditions. However, Peritoneal Dialysis is most commonly associated with Kidney Failure due to Chronic Kidney Disease.
The other type of Dialysis known as Haemodialysis also serves the same purpose. However, Peritoneal Dialysis (PD) comes with less complications & if eligible, is an often preferred option by young, employed patients.
Unlike Haemodialysis, where the patient’s blood goes to a dialyzer tank outside the body, in PD, the tissue sheet lining the patient’s abdomen from within (Peritoneum) acts as the “Dialysis Tank” itself.
How does your Abdomen work as a Dialysis Tank in PD?
This works in the following ways:
1. There is some space between the two layers of Peritoneum which normally has very little body fluid (50 mL) in there. This is the Peritoneal space. It is an “elastic” space that can “inflate like a balloon” to allow more fluid in there.
This is the space where Fresh Dialysate Fluid can be pumped in before every treatment session.
2. The Peritoneum is “selectively porous” in nature. This makes it similar to the dialyzer membrane filter within in a haemodialysis machine.
3. Further, it receives extremely rich blood supply too. So it serves as a relatively convenient location to separate out unwanted substances in the bloodstream.
What goes on during Peritoneal Dialysis (PD)?
👉 For you to begin your PD treatment, your doctor will first have to create an “Access” to your abdominal cavity.
For this, your doctor will perform a minor surgery to place a narrow, short plastic tube called a catheter into your abdomen (belly) to make a long-term access.
This plastic tube stays in place even when the person is not undergoing dialysis.
👉 During the treatment, your abdominal area (called the peritoneal cavity) slowly fills up with dialysate through the catheter.
👉 Your blood continues to circulate within the blood vessels (arteries and veins) that line your peritoneal cavity as usual. The blood vessel walls and the tissue lining of peritoneum act as a “continuous exchange-filter space”.
👉 The pressure at which the dialysate fluid is filled in the peritoneal space is maintained below the pressure at which blood normally circulates within the arteries & veins.
This is what allows for the extra fluid & waste products in the bloodstream to move out into the dialysate.
👉 After each PD session which usually lasts for 4-6 hours, the Used Dialysate fluid is removed from your belly and discarded away.
Types of Peritoneal Dialysis
There are two major kinds:
1️⃣ Continuous Ambulatory Peritoneal Dialysis (CAPD)
2️⃣ Automated Peritoneal Dialysis (APD).
🔔 Continuous Ambulatory Peritoneal Dialysis (CAPD)
This is the only type of peritoneal dialysis that does not require machines. Patients do this themselves, usually four or five times a day at home and/or at work.
The patient puts a bag of dialysate (about two quarts) into his/her peritoneal cavity through the catheter. The dialysate stays there for about four or five hours before draining it back into the bag and disposing of it. The technical name for this procedure is an Exchange.
Everytime patients do an Exchange, they need a fresh, new bag of Dialysate.
While the dialysate is in their peritoneal cavity, patients can go about their usual activities at work, at school or at home.
🔔 Automated Peritoneal Dialysis (APD)
APD usually is done at home using a special machine called a Cycler (image below).
APD is similar to CAPD except that a number of cycles (exchanges) occur. Each cycle usually lasts 1-1/2 hours and exchanges can continue throughout the night while patients sleep.
Who qualifies for starting Peritoneal Dialysis?
Patients eligible for Peritoneal Dialysis treatment are usually:
1️⃣ Not acutely sick
2️⃣ Below 40 years of age when starting Dialysis
4️⃣ Free from any prior heart disease (that could affect heart pumping)
Advantages of Peritoneal Dialysis
1️⃣ Kidney failure patients live longer with Dialysis than otherwise. Moreover, patients on Peritoneal Dialysis have a “survival advantage” of about 2 years as compared to patients on Haemodialysis.
2️⃣ Excess levels of Blood Urea Nitrogen (BUN) in CKD cause many of the known heart, lung & nerve complications associated with kidney failure.
PD has been shown to clear-out excess blood Urea more efficiently in a single session as compared with Haemodialysis (HD).
3️⃣ Most patients on PD need to depend less on Anaemia medication as compared to those on CKD.
This means that while PD cannot prevent Anaemia in CKD, it can significantly slow down the pace of worsening of your Anaemia. This is not true with Haemodialysis.
4️⃣ It helps to curb increases in blood Phosphorus levels more effectively that Haemodialysis.
This means patients on PD are less likely to get phosphate kidney stones or show deterioration of the bone disease associated with CKD as compared to those on Haemodialysis.
5️⃣ Peritoneal Dialysis is a better option for patients who do not have heart disease at the time of starting Dialysis.
This is because it removes less excess fluid in our body per session as compared to Haemodialysis. This makes PD less abrupt and rather gentle on heart muscles.
However, if kidney failure patients already have a weak heart pumping, then removing more fluid at a time becomes a priority. This is to reduce the burden on the already weak heart. In such cases, Haemodialysis is a better alternative.
6️⃣ Peritoneal Dialysis can be easily done at home by the patients themselves.
This “freedom” from the bindings of depending on in-centre dialysis makes PD a preferred option for young patients below 40 who have employment or study commitments.
Does Peritoneal Dialysis have any complications?
Peritoneal Dialysis efficiently cleanses the blood of excess wastes to effectively prolong survival in CKD patients. However, it is an external intervention that interferes with the usual workflow of the body as well. This brings about certain complications both in the short & the long term as listed below:
- Catheter site infection
Poor hygiene of the site on your tummy where the catheter is inserted, could cause infections locally.
This refers to infection of the peritoneum (biological tissue bag within the abdomen) that acts as the “filter space” in Peritoneal Dialysis
The Catheter for Peritoneal Dialysis is basically a “foreign body” that stays put even when the patient is not getting dialysis. So, it can act as a “portal of entry” for infection causing germs into the otherwise sterile abdominal cavity as well.
Peritonitis is a dangerous & extremely painful complication. The good news is,it is entirely preventable by maintaining strict hygiene at all times, especially at the catheter site.
Long-term Complications (after 5-6 years)
1. Weight Gain
2. Heart enlargement and poor pumping
3. Sustained increase in blood Phosphate levels that can worsen bone pain & cause kidney stones
4. Poor control over decline of blood Albumin levels
Other Dialysis FAQ
Apart from these core details about Haemodialysis, should you want to seek more clarity on issues like:
– If you still need to take your kidney meds after starting Dialysis
– Your Renal Diet
– If you can Work while on Haemodialysis
– If you can travel while on Haemodialysis
– Need for a Kidney Transplant
Then click on the image link below 👇