A method of removing waste products from your blood when your kidneys can't adequately do the job any longer. This procedure filters the blood in a different way than does the more common blood-filtering procedure called hemodialysis. During peritoneal dialysis, a cleansing fluid flows through a tube (catheter) into part of your abdomen. The lining of your abdomen (peritoneum) acts as a filter and removes waste products from your blood. After a set period of time, the fluid with the filtered waste products flows out of your abdomen and is discarded.
You need dialysis if your kidneys no longer function well enough. Kidney damage generally progresses over a number of years as a result of long-term conditions, such as:
-High blood pressure
-Kidney inflammation (glomerulonephritis)
-Multiple cysts in the kidneys (polycystic kidney disease)
-Unlike haemodialysis, an advantage of peritoneal dialysis is that regular visits to a dialysis unit are not required, and it can be carried out at home.
-There are also fewer restrictions on diet and fluid intake for people having peritoneal dialysis, compared with those having haemodialysis.
-The procedure needs to be carried out every day, which you may find disruptive.
-You may also find it upsetting to have a thin tube (catheter) left permanently in your abdomen (tummy), although it can often be concealed under clothing.
-Incresed risk of developing peritonitis, an infection of the thin membrane that lines your abdomen.
-In rare cases, your peritoneum may gradually become thickened and scarred. Some people may need to switch to haemodialysis after a few years to stop this happening.
-The dialysis fluid used can cause a reduction in protein levels, which can lead to a lack of energy and, in some cases, malnutrition.
-Weight gain is also a possible side effect.
During peritoneal dialysis:
The dialysate flows into your abdomen and stays there for a prescribed period of time (dwell time) — usually four to six hours
Dextrose in the dialysate helps filter waste, chemicals and extra fluid in your blood from tiny blood vessels in the lining of your abdominal cavity
When the dwell time is over, the solution — along with waste products drawn from your blood — drains into a sterile collection bag
The process of filling and then draining your abdomen is called an exchange. Different methods of peritoneal dialysis have different schedules of exchange. The two main schedules are:
1) Continuous ambulatory peritoneal dialysis (CAPD), where you fill your abdomen with dialysate, let it remain there for a prescribed dwell time, then drain the fluid. Gravity moves the fluid through the catheter and into and out of your abdomen.
2) Continuous cycling peritoneal dialysis (CCPD), where the cycler automatically fills your abdomen with dialysate, allows it to dwell there and then drains it to a sterile bag that you empty in the morning.
You'll need an operation to insert the catheter that carries the dialysate in and out of your abdomen. The insertion might be done under local or general anesthesia. The tube is usually inserted near your bellybutton.
After the tube is inserted, your doctor will probably recommend waiting up to a month before starting peritoneal dialysis treatments to give the catheter site time to heal.
You'll also receive training on how to use the peritoneal dialysis equipment.
To check if your dialysis is removing enough waste products, your doctor is likely to recommend tests, such as:
1) Peritoneal equilibration test (PET). This test compares samples of your blood and your dialysis solution during an exchange. The results indicate whether waste toxins pass quickly or slowly from your blood into the dialysate. That information helps determine whether your dialysis would be improved if the solution stayed in your abdomen for a shorter or longer time.
2) Clearance test. A blood sample and a sample of used dialysis solution are analyzed to determine how much of a certain waste product (urea) is being removed from your blood during dialysis. If you still produce urine, your doctor may also take a urine sample to measure its urea concentration.
If the test results show that your dialysis schedule is not removing enough wastes, your doctor might change your dialysis routine to:
-Increase the number of exchanges
-Increase the amount of dialysate you use for each exchange
-Use a dialysate with a higher concentration of dextrose
Infections. An infection of the abdominal lining (peritonitis) is a common complication of peritoneal dialysis. An infection can also develop at the site where the catheter is inserted to carry the cleansing fluid (dialysate) into and out of your abdomen. The risk of infection is greater if the person doing the dialysis isn't adequately trained.
Weight gain. The dialysate contains sugar (dextrose). Absorbing some of the dialysate might cause you to take in hundreds of extra calories daily, leading to weight gain. The extra calories can also cause high blood sugar, especially if you have diabetes.
Hernia. Holding fluid in your abdomen for long periods may strain your muscles.
Inadequate dialysis. Peritoneal dialysis can become ineffective after several years. You might need to switch to hemodialysis.
When should I consider peritoneal dialysis?
Peritoneal dialysis may be the better option if you:
-Can't tolerate the rapid changes of fluid balance associated with hemodialysis
-Want to minimize the disruption of your daily activities
-Want to work or travel more easily
-Have some residual kidney function
When is peritoneal dialysis not suitable?
-Peritoneal dialysis might not work if you have:
-Extensive surgical scars in your abdomen
-A large area of weakened abdominal muscle (hernia)
-Limited ability to care for yourself, or a lack of caregiving support
-Inflammatory bowel disease or frequent bouts of diverticulitis
What are the differences between Continuous ambulatory peritoneal dialysis (CAPD) and Continuous cycling peritoneal dialysis (CCPD)?
-You may need three to five exchanges during the day and one with a longer dwell time while you sleep
-You can do the exchanges at home, work or any clean place
-You're free to go about your normal activities while the dialysate dwells in your abdomen
-You must remain attached to the machine for about 10 to 12 hours at night.
-You aren't connected to the machine during the day. But in the morning you begin one exchange with a dwell time that lasts the entire day.
-You might have a lower risk of peritonitis because you connect and disconnect to the dialysis equipment less frequently than you do with CAPD.