Renal replacement therapy involves partial or total replacement of kidney function in a patient with renal failure. Procedures range from various dialysis methods to kidney transplantation. A transplant becomes necessary if only because dialysis is permanently associated with severe damage to the blood circulation.
What is renal replacement therapy?
Renal replacement therapy involves partial or total replacement of kidney function in a patient with renal failure. Procedures range from various dialysis methods to kidney transplantation. Renal replacement therapy corresponds to the medical treatment pathway for complete renal failure. Renal replacement therapy treatments partially or totally replace kidney function. Therapeutically, there are several individual procedures with this goal: hemodialysis, peritoneal dialysis and kidney transplantation are the best known of these. Treatment modalities such as hemodialysis and peritoneal dialysis are also grouped under the term renal replacement procedures. Renal replacement procedures are used for both temporary and permanent partial or total loss of kidney function. Procedures such as ultrafiltration also fall into this methodological group. As a transplantation of a donor kidney into an organ recipient, kidney transplantation is the most rigorous renal replacement procedure.
Function, effect, and goals
The kidneys perform detoxifying functions. Without this detoxification, humans cannot survive in the long term. Therefore, total renal failure is life-threatening. To save the patient’s life, renal replacement therapy with detoxifying properties must be given. Which procedure is used is decided on a case-by-case basis. Transplantation of a donor kidney, for example, is the only treatment option apart from dialysis for patients with terminal renal failure. Following a living or post-mortem donation, the patient is transplanted with a new kidney in an allogeneic, heterotopic or substitutive transplantation. The blood group and immunological constitution of the donor and recipient must match as closely as possible for a transplant to take place. In most cases, the kidney is not transplanted to the actual location of the kidneys, but to the pelvic region. The patient’s own kidneys usually remain in the body and the new kidney supports them in their work from then on. The blood vessels of the donor kidney are sutured to the pelvic vessels for this purpose. The urinary tract of the transplant is directly connected to the bladder. As a rule, the new kidney starts working during the transplantation. To prevent rejection by the immune system, the patient is usually given immunosuppressants. However, some patients are generally not suitable as transplant recipients. This is especially true for patients in whom a particular disease triggers the kidney disease and will cause it to recur even after a transplant. In such cases, dialysis procedures are indicated as renal replacement therapy. The same applies to patients for whom no suitable donor kidney can be found in the near future. In peritoneal dialysis, the peritoneum serves as the dialysis membrane. Dialysate is allowed to enter the peritoneal cavity during treatment. The peritoneum is used as a membrane to flush out substances that need to be excreted. Access to the peritoneum is provided by a catheter system. This system is passed into the peritoneal cavity by means of subcutaneous tunneling. In hemodialysis, on the other hand, a dialyzer filters the excretory substances out of the blood. To ensure the flow of blood into the dialyzer, the nephrologist places a so-called dialysis shunt on the patient. These three methods of renal replacement therapy are by no means the only ones. In the field of dialysis procedures, for example, SLEDD and ultrafiltration also count as kidney replacement procedures, which are considered a type of specialty dialysis. However, no dialysis can permanently replace a kidney. So, in the long run, once kidneys fail completely, transplantation is indicated.
Risks, side effects and dangers
The different kidney replacement therapies are associated with different risks and side effects. For example, with peritoneal dialysis, abdominal pain is common. Fever is also a common side effect.If work is not carried out in a sterile manner, infections and fungi can be introduced via the catheter system. Wound infections at the entry site of the catheter also occur. Compared with hemodialysis, peritoneal dialysis removes more proteins, but less creatinine and urea. In the long run, any dialysis can cause damage to blood vessels, joints or even the heart. Dialysis procedures are a great strain on the patient, both physically and psychologically, and require strict adherence to certain dietary rules. For example, foods containing potassium must be avoided, otherwise the risk of heart disease increases. Since dialysis washes vital vitamins out of the body, dialysis patients must also take nutritional supplements. They usually feel their quality of life is limited. Since many dialysis procedures take place once a day, they are no longer free even to plan their daily lives. Kidney transplantation limits the quality of life much less in the long run. This treatment option is also the only kidney replacement therapy that can be used effectively over the long term. It improves the patient’s quality of life and general health, but like dialysis, it is associated with risks. In addition to the general risks of surgery and anesthesia, there is always a risk of rejection with a kidney transplant. This risk is enormously stressful for the patient psychologically. Rejection can still occur under certain circumstances even if the body seems to have accepted the kidney immediately after surgery. Although immunosuppressants generally reduce the rate of rejection, rejection is never completely eliminated in transplantation. Inflammatory immune reactions are also somewhat of a risk. Nonetheless, at a certain stage, transplantation is the only possible renal replacement therapy.
