How does Dialysis work? Peritoneal Vs Haemodialysis
There are two major types of dialysis : Hemodialysis and Peritoneal Dialysis.
- Hemodialysis means that blood is transported to the external system that is purified until it is returned to the body.
- Peritoneal dialysis: involves pumping dialysis fluid into the space inside your abdomen (tummy) to draw out waste products from the blood passing through vessels lining the inside of the abdomen.
These 2 treatments are outlined on this page.
Detail on Haemodialysis
Preparing for treatment
You will normally have an arteriovenous fistula (AV fistula) in your arm before haemodialysis can start. This blood vessel is formed when an artery is connected to a vein.
The blood vessel becomes wider and stronger by joining a vein and an artery together. This helps you to move your blood back and forth to your dialysis system.
The AV fistula is generally performed about four to eight weeks before haemodialysis starts. This makes it possible to repair the tissue and skin around the fistula.
If your blood vessels are too small to produce an AV fistula, you can prescribe an alternative procedure called an AV graft. To connect the artery to the vein, a piece of synthetic tubing is used.
A neckline can be offered to you as a short-term measure or in an emergency. There’s a tube in your neck inserted into a vein.
The haemodialysis process
Most people need 3 hemodialysis sessions a week, each lasting approximately 4 hours. This can be performed at home or in the hospital.
In your AV fistula or graft 2 thin needles will be inserted and taped into place. One needle extracts blood slowly and transfers it to a device called a dialyser or system for dialysis.
Also Read: How To Control Thirst for Dialysis Patients?
The dialyser consists of a series of membranes that act as filters and a special liquid known as dialysate.
The membranes remove waste materials from the blood into the dialysis fluid.
The dialysis fluid used is injected from the dialyser and the filtered blood passes through the second needle back through your bloodstream.
You can sit or lie on a sofa, recliner or bed during your dialysis sessions. You can read, hear music, use or sleep on your mobile phone.
Hemodialysis is not painful, but some people experience a little dizziness and feel ill, and may have muscle cramps.
This is due to sudden changes in blood fluid levels during therapy.
The needles are taken off and a pad is applied to avoid bleeding after the dialysis session.
Usually, you will go home shortly after you are treated in a hospital.
Detail on Peritoneal dialysis
There are 2 main types of peritoneal dialysis:
- continuous ambulatory peritoneal dialysis (CAPD) – where your blood is filtered several times during the day
- automated peritoneal dialysis (APD) – where a machine helps filter your blood during the night as you sleep.
Both treatments can be done at home once you have been trained to carry them out yourself.
They’re described in more detail below.
Preparing for treatment
An opening in your abdomen is needed before you can have CAPD or APD.
This allows the dialysis fluid to be pumped into the space of the abdomen (the peritoneal cavity).
A cut is normally done under the bottom button. A cut (incision). In the incision is inserted a thin tube called a catheter and usually a few weeks before therapy begins the opening shall be healed.
The catheter is fixed permanently to your abdomen, which is hard for certain people.
You should take it off and go to Haemodialysis if you cannot get used to the catheter.
Continuous ambulatory peritoneal dialysis
The equipment used to carry out CAPD consists of:
- a bag containing dialysate fluid
- an empty bag used to collect waste products
- a series of tubing and clips used to secure both bags to the catheter
- a wheeled stand that you can hang the bags from
Firstly, you bind the catheter to your abdomen with the dialysate fluid container.
This enables the fluid to drain through the cavity where the fluid remains for several hours.
During the peritoneal cavity, the dialysis fluid is drawn from the blood and into the fluid by waste products and fluid in the blood through the cavity.
The old fluid is drained into the waste bag a few hours later. New fluid is then moved from a fresh bag into your peritoneal cavity, and left there until the next session.
It takes 30 to 40 minutes to complete this phase of exchange the liquids without any discomfort.
It is not painful to exchange the fluids, but first of all, you may find it unpleasant or weird to fill your abdomen with fluid. This should begin to get less apparent as you become comfortable with it.
This must be repeated about 4 times a day for most people who use CAPD. The bags are disconnected and the end of the catheter is closed between treatment sessions.
Automated peritoneal dialysis (APD)
Automated peritoneal dialysis (APD) is similar to CAPD unless the exchange of fluids is regulated by a machine during sleep.
Before you go to bed, you tie a bag filled with dialysis fluid to the APD. When you sleep, a lot of fluid exchanges are automatic.
It normally takes 8 to 10 hours to be mounted on the APD rig.
Any dialytic fluid will be left in the abdomen at the end of the therapy session. Drain this during your next session.
An exchange can be disrupted during the night if, for example, you have to get to the bathroom.
Some people with APD worry about the potential of a power reduction or other technical issue.
But normally it is safe to skip an exchange for 1 night while you resume treatment in 24 hours.
If you have technical issues, you’ll receive the phone number for a 24-hour hotline you can dial.