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What is haemodialysis?
Haemodialysis is not a cure but takes over some of the jobs the kidneys do. You may also need to take medications and change your diet in order to stay as healthy as possible.

Haemodialysis is a treatment that:
• removes waste products from the blood
• balances essential salts and minerals that would become dangerous if the levels became too high
• removes excess fluid from the blood

The waste products, salts and excess fluid build up in the body because your kidneys aren’t working properly.

Haemodialysis uses a kidney machine to pump blood out of the body, through tubing to a filter (called a dialyser) and then back into the body.

At any one time about 1 cup (250 ml) of blood is outside the body. The average adult has between 4 to 5 litres of blood and so can easily cope with this amount out of the body.

To stop your blood from clotting, a drug will be injected into the machine tubing; we call these anticoagulants. There are different types of anticoagulants; common ones used are heparin, dalteparin, tinzaparin and enoxaparin.

The dialyser is a bundle of hollow fibres that allows water and waste products to pass through. At the same time, red blood cells, proteins and other useful substances are kept in the blood.

How do you gain access to the blood in my veins?
In order to have haemodialysis treatment, we will need to gain access to the blood in your veins.

We call this vascular access and there are 4 different types:

1. A fistula
A connection of an artery and a vein created by an operation. Before each treatment, needles are inserted into the fistula to gain access to the blood. At the end of treatment, they are taken out.

2. A graft
This is similar to a fistula, but instead of the artery being attached directly to a vein, a flexible synthetic tube is used to connect the blood vessels. Before each treatment, needles are inserted into the graft to gain access to the blood. At the end of treatment, they are taken out.

3. A tunnelled dialysis catheter (or line)
A tunnelled dialysis catheter is a long hollow tube made out of polyurethane (a strong, flexible man-made plastic). The catheter is put into a large vein in your chest but a part stays outside your body. The catheter stays in place until it is no longer needed.

4. A temporary dialysis catheter (or line)
You may need a temporary catheter if you need dialysis urgently or in an emergency. This type of catheter is put in a large vein:

• in your neck - a jugular line. This can stay in place for up to 14 days
• in your groin - a femoral line. This can stay in place for up to 7 days

What happens on my first dialysis treatment?

Your first 3 treatments will be shorter than your regular prescription time while your body gets used to dialysis. Some examples are below of what your first 3 treatments could be.
• Treatment 1 will be 2 hours
• Treatment 2 will be 2 hours 30 minutes
• Treatment 3 will be 3 hours

Your blood pressure, weight and height will be measured and blood tests taken. Your nurse will ask you questions about your general health and how you manage at home for example.

If you have a fistula or graft, an experienced dialysis nurse will put two needles into the veins. This might feel uncomfortable. Once the needles are in place the discomfort should go away. If this is not the case, speak to your dialysis nurse.

The new, soft fistula can “blow” or “bump”. This is where the vein tears a little and blood leaks into your arm which can cause bruising, swelling and pain. This may happen a few times but the more your fistula is needled, the stronger it gets. It might not happen at all. Smaller needles may be used at first.

If you have a tunnelled dialysis catheter or a femoral line, this will be used to gain access to your blood.

During your dialysis treatment
If you feel unwell (sick, dizzy or feel cramps anywhere), tell someone quickly. Your blood pressure can drop on dialysis and nurses may give you an infusion of saline (salt water) to treat it.

During these first 3 treatments you must not eat as this may make you unwell. You will be offered a drink and a snack when your treatment is finished.

After your third treatment a decision about your regular prescription will be made. This will tell you how long you need to be on the dialysis machine for each treatment. This will be for at least 3½ hours or longer if you need it.

If you are having your first haemodialysis as an outpatient

If your first haemodialysis treatment will be as an outpatient please:

• Do not take your blood pressure tablets on the day of your dialysis (if you have been prescribed these) as having haemodialysis treatment can lower your blood pressure.
• Bring all your tablets and medicines that you take. The sister or doctor will need to make an up-to-date list of what you take and some of your medication may change.

Hospital transport to your first dialysis can be arranged. Your transport to future haemodialysis treatments will be discussed with you.

With thanks to the Vascular Services Institute at Sheffield Teaching Hospitals NHS Foundation Trust for their permission to use the information.
Issue date April 2022
Review date April 2025

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The National Kidney Federation cannot accept responsibility for information provided. The above is for guidance only. Patients are advised to seek further information from their own doctor.