Dialysis

Dialysis does some of the work of healthy kidneys, which filter waste and extra water from the blood. In haemodialysis a machine filters your blood. In peritoneal dialysis the lining of your tummy does the filtering. Dialysis can help you feel better and live longer, but it is not a cure for kidney failure.

Dialysis is needed when the kidneys are damaged and can no longer filter the blood. After acute kidney injury, a sudden loss of kidney function, you may need it only until your kidneys recover. In chronic kidney disease it is usually needed for the rest of your life, or until you have a kidney transplant. Some people cannot have dialysis or choose not to, and medicines can still ease symptoms.

Before dialysis starts you need a small operation to make the access: a fistula in the arm, usually under local anaesthetic, or a tummy catheter, under local or general anaesthetic.

A haemodialysis session goes like this:

1. Two needles are placed in your fistula, usually in the arm. Numbing cream or spray can help.
2. Each needle joins a tube that connects to the machine.
3. Blood flows to the machine, passes through a filter that removes waste and extra water, and returns to your body. The machine also checks your blood pressure.
4. A session lasts around 4 hours, and most people need 3 a week.

In peritoneal dialysis, fluid runs from a bag into your tummy through the catheter, stays a few hours while it absorbs waste, then drains into a second bag. This is called an exchange. Exchanges are done by hand during the day or by a machine overnight, after training with a nurse.

Both types can leave you tired and sick, and haemodialysis can cause cramps and dizziness. Tell your team, who can often help. Wash your access daily and feel for the buzz of a working fistula. You may need to limit salt, phosphorus-rich foods and fluids, and eat more protein.

Ask for urgent advice, and say you are on dialysis, if:

• The skin around your fistula or tummy tube is painful, swollen or a different colour
• You have tummy pain or a lump in your tummy
• You have a very high temperature, or feel hot, cold or shivery
• You pass much less urine, or the drained fluid looks cloudy

If a fistula starts to bleed, call for emergency help at once. The bleeding will not stop without treatment.

Haemodialysis can cause a skin infection around the fistula, bleeding from it, and too much fluid in the body, which can lead to heart failure. Sudden changes in fluid and body chemicals can cause cramps and low blood pressure.

Peritoneal dialysis can cause infection where the catheter enters, a hernia (a lump where the tummy muscles are weak) and peritonitis, an infection of the tummy lining. Peritonitis needs treatment straight away, as it can lead to sepsis.

Dialysis replaces only part of what the kidneys do. Signs that it is working include more energy, a better appetite, and less breathlessness and swelling.

After acute kidney injury, dialysis may stop when the kidneys recover. In chronic kidney disease it continues until a transplant, so ask your team whether a transplant is an option for you.