Chronic Kidney Disease and Dialysis

In the later stages of chronic kidney disease dialysis is necessary to filter out the waste products that the kidneys are no longer able to. Without dialysis the waste would simply build up in the body leading to coma and death.

There are two main types of dialysis:

• Haemodialysis.This is where the blood is circulated outside the body through a machine which contains special filters. The patient is connected to the machine by two thin flexible tubes (catheters).

  Surgery is needed to enlarge a blood vessel in the arm which is then used for inserting the catheters.

  Haemodialysis usually needs to be done for 3 to 4 hours, 3 times per week but this can vary depending on the how well the kidneys work, how much fluid weight has been gained between treatments, body size and how much waste is in the body.

  Haemodialysis is usually given in hospital or at a specialist dialysis centre although some people can use this method at home.

  The NHS site gives the following criteria for those who are suitable fpr home haemodialysis:

  1. Those who are able and willing to learn to carry out the procedure and to continue with the treatment;
  2. Those who have remained in a stable condition while on dialysis;
  3. Those who don't have other diseases that would make it too difficult or unsafe to carry out haemodialysis at home;
  4. Those who have blood vessels that are suitable for inserting the catheters that carry the blood to and from the dialysis machine;
  5. Those who, if a carer is needed, have a carer (or more than one carer) who has decided, after discussing all the issues, to help with the haemodialysis;
  6. Those who have a home that already has enough space and facilities to set up and use the kidney machine, or whose home could be adapted to provide the space and facilities needed.
• Peritoneal Dialysis. This method relies on the natural filtering ability of the lining of the abdomen (the peritoneum). Peritoneal dialysis involves the surgical placement of a small soft tube into the lower abdomen. A sterile solution (dialysate) is passed through the catheter into the peritoneal cavity (belly). The peritoneum acts as a kind of filter between the blood vessels and the dialysate solution.

  Waste products and excess salt and water flow out of the blood, through the membrane and into the dialysate. After a certain amount of time the used dialysate and waste products are drained from the abdomen into an empty discard bag. The process than starts all over again. The act of draining out the used solution and adding fresh solution is called an exchange.

  There are two main types of peritoneal dialysis:

  1. Continuous ambulatory peritoneal dialysis (CAPD) in which a soft catheter is permanently placed in the lower abdomen. CAPD requires no machine, the dialysate is left in the abdomen for four to eight hours and then immediately replaced with fresh solution. This is done four to five times a day, every day. As its name suggests patients are able to move around and carry out daily activities with CAPD.
  2. Continuous cycling peritoneal dialysis (CCPD) in which a machine is used to do the dialysis fluid exchanges whilst the patient is asleep. (CCPD) takes 10-12 hours per session and most people need to be attached to the machine every night. Some people will need to do one additional exchange during the day.

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