Dialysis is a process of removing waste products and excess fluid which build up in the body when the kidneys are not functioning adequately. Dialysis uses a membrane as a filter and a solution called dialysate to regulate the balance of fluid, salts and minerals carried in the bloodstream. The membrane may be man made as in haemodialysis or natural as in peritoneal dialysis.
How does haemodialysis work?
Blood taken from the body to be cleaned in a filter known as a dialyser (artificial kidney). A dialyser works on the principle of blood flowing along one side of semi-permeable membrane made of cellulose or a similar product, with the dialysate flowing along the another side. The dialysate contains a regulated amount of minerals normally present in the blood, but in renal failure they are present in excess. The membrane has tiny holes of different sizes so that the excess fluid and substances in the blood pass through at different rates, small molecules quickly and larger ones more slowly, to be taken away in the dialysate until a correct balance in the blood achieved.
As only a very small amount of blood can circulate from patient to dialyser at any given time, blood needs to circulate from patient to dialyser and back to patient for about 4 hours. Treatment is usually 3 times per week.
Blood is carried from the patient to the dialyser and returned through dialysis lines (plastic tubes) which are connected to the patient .
The joining of vein and artery just under the skin, usually on the forearm makes the vein swell to allow needles to be inserted and removed after each treatment. Between treatments only a small scar and swelling are visible.
- Central Venous catheter
A soft plastic tube inserted into the internal jugular vein in the neck. This can be used as a temporary access for dialysis until fistula is ready , and is capped off and left in the place when not in use.
Will dialysis cure my kidney failure?
Dialysis takes over the role of the kidneys. It will not cure your kidney failure. The only alternative to kidney dialysis is transplantation. However not everyone may be suitable to have kidney transplant
On very rare occasions kidneys have been known to make a temporary recovery-but don’t count on it!
Will dialysis keep me well?
There is no real substitutes for your own healthy kidneys and we cannot promise that you will feel as fit as you did before kidney failure. To keep as well as possible your treatment will consist of the 3 Ds – dialysis, diet and drugs.
The haemodialysis diet is quite strict, limiting your intake of fluid and foods which are high in salt, potassium and protein. This is not as bad as it sounds and imaginative cooking can produce nourishing and tasty meals. Eating out is possible with a little care.
There will be times when you will feel very tired-it’s the same with most chronic illnesses. Stick to the advice you are given and you should be well enough to do most normal activities.
Living with Kidney Failure
Becoming a dialysis patient is a turning point in your life. Modern medicine makes it possible for you to live long and continue with many day-to-day activities.
As patients, we know that the path will not always be easy. Dialysis is now part of your life and that of your family. Do not let it dominate-the aim is to enable you to enjoy a good quality of life.