Dialysis methods


What is dialysis?

Dialysis is one of the methods that can substitute for kidney function. The other two are peritoneal dialysis and transplantation. Patients with chronic kidney failure begin to experience severe symptoms when their kidney function falls below 15% of the normal. At this stage, the normal functions of the body cannot be maintained and a substitute method must be found.

Dialysis as a procedure uses the patient’s blood, a filter, and a special solution through which waste material that accumulates in the body is removed, while allowing the useful constituents tobe absorbed. This process requires a high blood flow, which is why communication between artery and vein is created. When the patient’s veins are not suitable then a graft of synthetic material is used between the artery and the central vein or a permanent catheter is placed in the central vein. Dialysis is done every two days and no special equipment is needed at home.

When and where can dialysis be performed?

Dialysis is performed in dialysis center or in hospital clinics. The nephrologist will explain everything that the patient needs to know about the dialysis process. It usually lasts four hours and takes place every two days.

The most advanced method of dialysis is online haemodiafiltration. It uses both dialysis techniques, diffusion and filtration, and the substitution fluid is a solution produced during the dialysis process and does not contain pyrogens. This method is indicated for patients with cardiovascular problems who experience frequent episodes of symptomatic hypotension, and it has been observed that urea, phosphorus, beta2-microglobulin and other medium and high molecular weight substances simultaneously improve. Accumulation of these substances otherwise causes pain and damage to various bodily systems in dialysis patients.

What does the dialysis involve?

The patient is connected to the machine through two special flexible catheters. Dialysis line insertion involves installation via punctures made in two sites. The first catheter directs the patient’s blood containing waste material (urea, creatinine, etc.) through a special line with the help of the dialysis machine pump to the filter, which permits exchange of substances from the blood into the solution and back. The blood, clean and free of excess fluids and waste substances, is transferred through the second catheter to the patient’s other puncture site.

This process is repeated several times during each session to achieve a balance of fluids and electrolytes in the patient’s blood. Since there is a direct pathway to the patient’s blood, it is easy to administer medicines or vitamins necessary for the body. The higher the quality of the component parts used in the dialysis system will also lead to better results for the patient. One important component is the filter.

How much is the patient's life affected by dialysis?

Dialysis is a procedure that is must be carried out frequently and over and extended period of time. The person will need to adapt to a new way of life and a new routine. They will have to spend a large proportion of their time in a dialysis unit, follow a specific dietary schedule, and take multiple medications.

With advances in medicine and biotechnology, the means used, as well dialysis techniques (such as online haemodiafiltration) are constantly improving, helping to prevent complications and ensure a better quality of life for patients.

Good cooperation between patient, doctor and nurse plays an important role in the course of dialysis

How important is the patient's diet?

The patient’s diet is very important for the progress and life of the patient. There are specific dietary rules that all patients must follow, but each diet is personalised on the basis of age, other medical conditions and the needs of each person.
Dietary rules

  • Limitation of fluid intake: Excessive fluid intake can lead to pulmonary oedema. Most kidney patients produce little or no urine, and need to limit their fluid intake. The water in foods is included in the permitted volume of fluids consumed. It is recommended that salt consumption be limited to counterbalance thirst.
  • Reducing consumption of foods with a high potassium content: Potassium accumulation may lead to dangerous arrhythmias. Fruit and vegetables are rich in potassium, so consumption may need to be be reduced. The manner in which they are prepared is also important. Fruit and vegetables should be cut into small pieces, and should be peeled. If they are to be cooked, soaking in water for two hours is recommended. They should then be rinsed, and left to boil for five minutes. Strain, and then continue boiling in fresh water until cooked.
  • Limiting phosphorus intake: Legumes, cereals and dairy products are all rich in phosphorus. When phosphorus accumulates in the body due to reduced renal excretion, it causes hyperparathyroidism in patients, causing potentially damaging skeletal changes, with serious and even potentially fatal consequences.

The nutritional requirements of patients with kidney failure depend on their activities. It is essential that the diet followed meets their caloric requirements in order to avoid muscle tissue breakdown.

Are there any side effects from dialysis?

Side effects depend mainly on the rate of fluid removal. Some of these include low blood pressure, fatigue, chest pain, nausea, headache, cramps, etc.

These symptoms may develop during or after the session. Their severity depends on the quantity and speed with which fluids are removed, and will vary from person to person and from session to session. Reducing fluid intake may help.