Dialysis (blood washing)

The dialysis or Blood washing is the purification of the blood, usually with an artificial kidney. It is used when the kidney functions are disturbed and the organs can no longer carry out the vital blood washing in the body. There are several different methods of dialysis, the most common being hemodialysis.

What is dialysis (blood washing)?

A dialysis is an artificial one Blood washing. Usually the kidneys do this work in the body. They clean the blood, filter out harmful metabolic products and drain excess water out of the body.

If the kidneys are sick or too weak and can no longer take on this function, the blood must be artificially purified. Dialysis is used in approximately 85-90% of all cases when there is a loss of function. During dialysis, the blood is drawn from the body's vasculature through a cleansing system that replaces the kidneys.

It is filtered, freed of pollutants and after the procedure flows back into the bloodstream. The purification of the blood is vital, without it the body would no longer function. If the kidneys fail without dialysis, harmful substances would accumulate in the organism and certain processes in the body would no longer be guaranteed.

Function, effect & goals

The dialysis is usually used for chronic kidney failure. But also in acute cases of poisoning, if the kidneys have to be supported in cleaning the blood or if they fail for a short time due to trauma (acute kidney failure). There are mainly two different methods of dialysis used.

One is hemodialysis, like which cleaning takes place outside the body via an artificial kidney (extracorporeal dialysis). The second type is peritoneal dialysis, in which the blood is filtered through the patient's peritoneum within the body. Hemodialysis is the most commonly used method. For hemodialysis, the patient is first placed a shunt in a small surgical procedure. This is a connection between the artery and vein and is used to widen the blood vessels to increase blood flow.

The blood is then fed into the artificial kidney via a hose system. There it flows in a rinsing liquid (dialysate) over a special membrane that filters out pollutants and water, and then flows back into the vascular system via the shunt. Dialysis lasts about four to five hours and is usually done three times a week in a dialysis center. In peritoneal dialysis, the blood inside the body is cleaned by using the peritoneum as a filter and the abdominal cavity as a container for the irrigation fluid.

The dialysate is filled into the abdominal cavity via a catheter and, after the cleaning process, discharged together with the pollutants it now contains. The patient can perform peritoneal dialysis independently at home. It is carried out either several times a day or overnight, whereby the nocturnal approach allows the person concerned more freedom and better mobility in everyday life.

Other methods of blood purification are hemofiltration, hemodiafiltration and hemoperfusion. With hemofiltration, the blood plasma is drawn out of the blood through a membrane and the pollutants are removed in the process. Here you work without dialysate. Hemodiafiltration is a combination of dialysis and filtration.

Hemoperfusion is used specifically for poisoning and is only carried out in special clinics. With this method, the blood is passed through adsorbents. These are substances that, due to their surface structure, are able to bind other substances such as poisons.

Side effects, risks & dangers

The dialysis cannot completely and permanently replace a kidney. Therefore, this procedure is only useful for a limited amount of time. If the kidneys fail completely, a kidney transplant must be sought in the long term.

Dialysis is also very stressful for the patient both mentally and physically. If the artificial cleansing of the blood is carried out over a period of years, damage to the vessels and joints or heart disease can occur. In addition, patients must observe certain dietary rules.

You should not consume more than one liter of fluids per day and you should avoid foods containing potassium, as the lack of activity of the kidneys leaves more potassium in the body than normal and this can damage the heart. In addition, the patient should take vitamins in the form of medication, as certain vital vitamins are flushed out of the body by dialysis.