Dialysis

What is dialysis?

The kidneys filter your blood to remove waste products produced by body metabolism, and excess fluid. These become urine and accumulate in your bladder to be passed out of your body when you urinate.

Dialysis is a procedure that replaces some of the functions of the kidneys when the kidneys no longer function properly.

Types of dialysis

There are 2 types of dialysis:

Haemodialysis

In haemodialysis (also known as 'blood washing'), blood is taken out from the body through a vascular access or 'blood line' and shunted through the dialysis machine.

This process "cleanses" the blood and removes waste products and excess water. The "cleansed" blood is returned back to the body via another blood line. These blood lines can be in the form of a dialysis catheter, an arteriovenous fistula or an arteriovenous graft.

Peritoneal dialysis

In peritoneal dialysis (also known as 'water dialysis'), a tube is surgically inserted into your abdomen.

The dialysis solution will be infused and drained through the tube while the lining of your abdomen (peritoneum) acts as a filter to remove waste from your blood.

Why do you need dialysis?

Your doctor will recommend dialysis if you develop end-stage kidney failure. Dialysis will help to:

• Remove waste products and excess fluid from the blood to prevent toxin build-up in your body.
• Maintain the proper balance of fluid and various electrolytes (e.g. potassium and sodium) in your body.

Alternatively, your doctor may recommend a kidney transplant.

Who should not undergo dialysis?

Peritoneal dialysis may not be suitable if you have:

• Extensive surgical scars in your abdomen
• A hernia, which is a large area of weakened abdominal muscle
• Limited dexterity or ability to care for yourself
• Inflammatory bowel disease

Your doctor may recommend haemodialysis or a kidney transplant instead.

What are the risks and complications of dialysis?

Both haemodialysis and peritoneal dialysis come with risks and complications.

Haemodialysis

In haemodialysis, risks and complications include:

• Low blood pressure
• Anaemia, or low red cell count
• Muscle cramps during haemodialysis
• Dialysis-related amyloidosis, which is when beta-2 microglobulin protein builds up in the blood

Peritoneal dialysis

In peritoneal dialysis, risks and complications include:

• Weakening of the abdominal muscle resulting in the development of new hernia
• Infection in or around the catheter site
• High blood sugar, due to sugar (dextrose) in the dialysis solution

What can you expect in haemodialysis?

You will typically undergo haemodialysis at a dialysis centre.

Estimated duration

Haemodialysis is performed at least 3 times a week. Each session lasts about 4 hours.

Before the procedure

Your doctor will create a vascular access in your arm. This is a surgical procedure that creates a connection, also known as an arteriovenous (AV) fistula or an AV graft, between an artery (blood vessel carrying blood from your heart) and a vein (blood vessel carrying blood back to your heart).

In total, 2 needles will be inserted into the vascular access. Each needle is connected to a flexible tube that is connected to the dialysis machine. If an AV fistula or graft is not feasible, your doctor will insert a dialysis catheter into a big blood vessel in your neck.

During the procedure

A small amount of blood will be removed from you through one point of the vascular access, shunted through the dialysis machine, and returned to your body through the other point of the vascular access.

Your blood pressure and heart rate will be monitored during the treatment as these may fluctuate.

After the procedure

The medical team will remove the needles from your access site and apply a pressure dressing to prevent bleeding.

What can you expect in peritoneal dialysis?

You will typically undergo peritoneal dialysis at home daily.

Estimated duration

The duration of peritoneal dialysis depends on how the dialysis is performed:

• Continuous ambulatory peritoneal dialysis (CAPD): You will drain and fill 2 litres of the dialysis solution into your abdomen 4 – 5 times a day. Each time, the solution stays inside for a prescribed dwell time, usually 3 – 4 hours.
• Continuous cycling peritoneal dialysis (CCPD): Also known as automated peritoneal dialysis, where you must remain attached to the cycler machine for 8 – 10 hours at night, usually while you are asleep.

Before the procedure

A peritoneal dialysis catheter will be surgically inserted into your abdomen, usually near your belly button. The insertion might be done under local or general anaesthesia.

The catheter will carry the dialysis solution in and out of your abdomen during peritoneal dialysis.

Your doctor will wait for the catheter site to heal before you start peritoneal dialysis. This usually takes about 2 weeks.

During the procedure

You will fill your abdomen with the dialysis solution. Waste, fluid and chemicals will flow through the peritoneal membrane into the dialysis solution. You can walk about with the dialysis solution in your abdomen. After the prescribed period, you will drain out the solution and fill your abdomen with fresh solution (exchange).

If you are doing a CCPD, you need to start the machine before you go to sleep and do an exchange in the morning.

Care and recovery after dialysis

To achieve optimal results from your dialysis, you should:

• Take your medications according to your doctor's prescription.
• Eat a healthy diet, including food low in sodium and phosphorus.

If you undergo peritoneal dialysis, avoid:

• Soaking in a bath or hot tub
• Swimming in a lake, pond, river or non-chlorinated pool as you may get infections