Peritoneal Dialysis

Peritoneal dialysis is a special form of dialysis, i.e. it is a blood cleansing method. Its main use is in young and cooperative patients who can perform this procedure alone at home.


Classic dialysis is based on a semi-permeable membrane. The blood of the patient is lead through external tubes into the main apparatus, where the blood is filtrated through the membranes. On the other side of the membranes flows a dialysis solution, so-called dialysate. Blood cells do not pass through the membrane, but minerals and other minor substances do.


The dialysis solution is able to cleanse the blood and to accumulate its waste products and excessive amount of ions and other substances. In addition, the dialysis machine is able to get rid of excessive volume of water. After passing through the machine, the blood is brought back into the patient's body. Classical dialysis takes about 4 hours and it is usually repeated three-times a week.


Peritoneal dialysis is based on an interesting idea. The abdominal cavity has a large surface and it is covered by a membrane known as peritoneum, which is richly supplied by blood vessels. Would it be possible to use this cavity as a dialysis machine and the peritoneal membrane as the semi-permeable membrane used in classic dialysis? It is possible and peritoneal dialysis was born. Special opening is created in the abdominal wall and the abdominal cavity is filled with dialysis solution. The exchange of waste products, ions, fluid and others substances between local blood vessels and the fluid in abdominal cavity ensures the effectiveness of this method.


There are two main types of peritoneal dialysis – continuous ambulant peritoneal dialysis (CAPD) and continuous cycling peritoneal dialysis (CCPD). CAPD is more common. The patient must fill (and empty) the abdominal cavity several times a day. The main advantage of CAPD is that it does not need any machine. CCPD needs a simple pump, which fills the abdominal cavity with the solution and sucks it away after few hours. The advantage is that the patient does not have to be active and the procedure can be performed in the night when sleeping.


Before beginning the dialysis, it is necessary to create a permanent access into the abdominal cavity, which has form of a tube inserted through the abdominal wall.


Peritoneal dialysis is usually used in patients with chronic renal failure. It is not indicated in acute conditions.


The method is not designed for people who are not willing (or unable because of health reasons) to cooperate in the procedure. Unpleasant complication is a more frequent occurrence of local bacterial infections – peritonitis, which can easily progress into sepsis. Cautious hygienic standards reduce the risk, but not exclude it. The presence of fluid in the abdomen may compress the lungs (by elevated diaphragm) and intestines, causing constipation, or shortness of breath.


Freedom is the main advantage of peritoneal dialysis. The patient can perform it alone and does not need to regularly attend the procedure in local dialyzing center. The patient's own body becomes a sort of dialysis machine and this significantly improves the quality of life.


Jiri Stefanek, MD  Author of texts: Jiri Stefanek, MD
 Sources: basic text sources