What is dialysis?
Dialysis is a treatment in which toxins and excess water are removed from the blood, as a renal replacement therapy when kidney function is lost in some patients with impaired kidney.
The main task of the kidneys is to remove toxins and fluid from the blood, as it is dangerous for waste products to accumulate in the body. When dialysis is performed on a patient, it is a machine that helps the kidneys to do their job, at the moment when they stop working well. Thus, during the process:
- Excess salt, water and waste products are removed so that they do not accumulate in the body.
- Adequate levels of minerals and vitamins are maintained in the body.
- Helps control blood pressure.
- Helps the production of red blood cells.
There are two types of dialysis:
- Hemodialysis: is the common dialysis treatment and is characterized by the use of an artificial membrane. Blood purification is performed by an artificial kidney, which removes excess water, waste and toxins before returning it to the body. Each session can last about four hours.
- Peritoneal Dialysis: is characterized by the use of a natural membrane (the patient’s peritoneum). It consists of removing waste and excess fluid through a tube (catheter) into part of the abdomen. After a period of time, the fluid with the filtered waste is directed out of the abdomen and discarded. We distinguish between continuous ambulatory peritoneal dialysis (between 30 and 40 thorough sessions, four times a day) and automated peritoneal dialysis (when performed while the patient is asleep during the night).
Dialysis removes toxins and fluid from the blood.
Why is it performed?
Dialysis is performed in patients with renal failure, which is the terminal stage of chronic renal failure. This occurs when the kidneys are no longer able to perform their excretory function and are only functioning at 10-15%. It is a “standby” therapy until a kidney transplant can be performed or, sometimes, as the only supportive measure in cases where a transplant is not feasible.
Some renal pathologies that may require dialysis are: uremic encephalopathy, pericarditis, acidosis, renal failure, pulmonary edema or hyperkalemia.
What does dialysis consist of?
There are two types of dialysis but, whichever type it is, its mission is similar: to replace certain kidney functions. Thus, the objective is to eliminate waste products and excess fluid, balancing the amount of electrolytes and other substances.
During dialysis, a semi-permeable membrane separates the blood from the dialysis fluid. The membrane will allow some substances to pass through but not others: it allows waste products, water or electrolytes to pass from the blood into the dialysis fluid by a process called diffusion. The movement of all these substances depends on how permeable the membrane is, the size of the substances, what the dialysis fluid is composed of or the amount of blood in contact with the membrane. In fact, the more blood in contact with the membrane the more efficient the treatment will be.
In dialysis, it is the dialysis fluid that allows waste products to be removed from the blood. In addition, it contains substances that help with the imbalances caused by kidney failure.
Preparation for dialysis
The preparation for dialysis will depend on the type of dialysis chosen by the nephrologist. Depending on this, the patient will be fitted with a catheter or not, through which the dialysis fluid will be introduced.
In addition, it is always advisable to
- To have a healthy diet, low in potassium and proteins (renal diet).
- Maintain your kidney medication
- Get plenty of rest and sleep before and during dialysis.
After dialysis, it is normal for the patient to feel tired, weak and even shaky, so it is recommended to rest once you return home. However, as soon as you feel better, you can resume your normal daily routine. On the other hand, the area through which the dialysis has been introduced should be washed with soap and water and care should be taken with the scabs that will form.
Alternatives to this treatment
The alternative to dialysis is kidney transplantation, which consists of surgery to place a healthy kidney in a patient suffering from end-stage renal disease.
In order to perform a transplant, it is necessary to have a donated kidney that is compatible with the future recipient. The kidney transplant operation lasts approximately three hours.