Peritoneal dialysis is an important treatment for kidney failure – when the kidneys stop working properly. Peritoneal dialysis cleans the blood while it is inside the abdomen (tummy). This partly replaces the work of healthy kidneys.
Your child will have a catheter (a long, thin tube) into his or her abdomen. Several times a day – or overnight while your child sleeps – a special fluid (liquid) is put through the catheter. The lining of the peritoneal cavity, which is called the peritoneum, acts like a filter to remove extra water, salts and waste products from the blood into the fluid. After a few hours or longer, the fluid is drained out through the catheter.
You will be trained how to do peritoneal dialysis at home and how to look out for any possible complications. A team of healthcare professionals will do regular assessments – the amount of time on dialysis and the volume of fluid used will be adjusted especially for your child’s needs.
Peritoneal dialysis is often shortened to PD. It is one type of dialysis; the other type is haemodialysis, which uses a special machine to clean the blood and is usually done at hospital or sometimes at home.
For an overview of dialysis, and an introduction to both types, please read our topic, Dialysis
Preparing for dialysis
Before the procedure can start, your child need a procedure to place a peritoneal dialysis catheter (PD catheter) into his or her abdomen. Your child will be given a general anaesthetic, special medicine so he or she can sleep through the procedure and not feel any pain. Ideally the PD catheter should be placed several weeks before dialysis starts, to give time for the catheter to heal. This is called resting the catheter, meaning the catheter is put in but not used for dialysis. However, resting the catheter is not always possible if the child’s kidney function is deteriorating rapidly. In this situation PD may need to be started straight away.
The PD catheter is a soft, plastic tube that is about 30–40 cm long. Part of it sits inside the abdomen, and part of it outside. A surgeon makes a small cut in the abdomen to make a small hole. The PD catheter is inserted through the hole into the peritoneal cavity. First it runs under the skin and then it dips down into the lower part of the abdomen. There are usually two ‘cuffs’ along the catheter, which bind to the surrounding tissues to hold it in place. Children usually stay in the hospital overnight or longer to give it time to heal.
The place where the catheter comes out of the skin is called the exit site. It needs to be kept clean to avoid infection.
About peritoneal dialysis
Where peritoneal dialysis takes place
Most of the time, peritoneal dialysis is done at home. It may also be done in other places, such as school, other family members’ homes or while on holiday.
You will be trained on how to manage your child’s dialysis at home – a team of healthcare professionals will be available to call if you have any questions or problems. If your child is old enough, he or she will also be shown what to do.
You will be provided with all of the equipment and supplies you need. This includes bags of special fluid, medicines and cleaning equipment – all of which will be explained.
How it works
The peritoneum, which is the lining of the abdomen, can act as a filter. The space inside the peritoneum is called the peritoneal cavity or the peritoneal space.
There are several stages of peritoneal dialysis.
- Fill: a special fluid called dialysate flows from a bag, through the PD catheter, into the abdomen. You may be given pre-prepared bags of dialysate, or you may need to mix fluids from two bags.
- Dwell: the dialysate stays (dwells) in the abdomen for a set period of time. The dialysate contains a type of sugar called dextrose, which ‘pulls’ the waste products, excess water and salts out of the blood and through the peritoneum.
- Drain: the used dialysate with the waste products, extra water and salt is drained out of the abdomen into another bag, and then thrown away.
Each time the dialysate is passed into and then removed from the body is called an exchange.
Tests and doses
Your child will regularly visit the paediatric renal unit, a specialised unit for babies, children and young people with kidney conditions, which may be in a different hospital, to find out how he or she is responding to the dialysis treatment. The dialysis team will work out the ‘dose’ of dialysis – what is in the dialysate and how much is used – especially for your child.
Clearance
Your child will be checked to find out how much waste is removed from his or her blood in peritoneal dialysis – this is called clearance. This is done with blood tests and by analysing the dialysis fluid.
Each person’s peritoneum works differently. Your child may have a test called the peritoneal equilibration test (PET), which checks how quickly his or her peritoneum filters waste products and water.
Blood sugar
The dextrose in the dialysate can affect your child’s blood sugar level. Your child may have blood tests to monitor this.
Tests at home
You will also need to do some tests each day, and record the results in a diary. You will need to weigh your child and measure his or her blood pressure – you will be given specific targets that are right for your child.
You will also be asked to take his or her temperature.
After each dialysis session, you will need to record the filtration volume – this is the amount of dialysate that is drained out of your child’s body.