Peritoneal dialysis is a therapeutic procedure in nephrology, which is an intracorporeal (inside the body) blood purification procedure used to detoxify the blood and thus the entire organism. Peritoneal dialysis is divided into different subsystems. Continuous ambulatory peritoneal dialysis (CAPD) and automated peritoneal dialysis (APD) are of particular importance for home dialysis treatment. For a few years now, peritoneal dialysis has replaced hemodialysis as the most commonly used system for home dialysis, as various studies have shown that mortality can be significantly reduced by the use of peritoneal dialysis, especially in the first years of treatment. The use of peritoneal dialysis as a home dialysis procedure has many advantages for the patient and, if applicable, for his or her relatives. Both CAPD and APD as home dialysis procedures, with optimized equipment technology depending on individual needs, represent a clear improvement in quality of life. They make it easier for working patients in particular to continue their activities, so that the proportion of peritoneal dialysis patients as the leading home dialysis procedure continues to increase. For the treatment of end-stage renal disease requiring dialysis, transplantation of a donor kidney is without question the best possible treatment option in terms of quality of life and mortality rate (death rate). However, due to the relatively high incidence of ESRD, the demand for donor kidneys is greater than the number of donor kidneys, so that many renal failure patients have to wait several years for a kidney. Particularly in this waiting phase, peritoneal dialysis using CAPD or APD should be considered reasonable, since the probability of dying from acute renal failure (ANV) is relevantly lower when these procedures are used than with hemodialysis. Despite these advantages, there has been a lower uptake of home peritoneal dialysis in recent years, as there is now a comprehensive network of outpatient dialysis centers and clinic dialyses, and learning how to perform peritoneal dialysis correctly is judged to be relatively difficult. In recent years, the importance of home treatment has declined, particularly because the age of patients requiring dialysis has shifted upward. With increasing age, the willingness to acquire a sound knowledge of the necessary parameters of dialysis treatment generally decreases. Although the treatment of patients requiring dialysis using home dialysis methods is declining, the proportion of patients regularly using CAPD and APD has increased in recent years. This is based in part on the fact that it has been found that using CAPD and APD preserves residual renal function longer, which plays an enormous role as a factor in patient mortality.
Prerequisites for home peritoneal dialysis
- In principle, the prerequisites for home hemodialysis are similar to those for home peritoneal dialysis. Any patient requiring dialysis who wishes to undergo home peritoneal dialysis treatment must meet certain quality criteria to be eligible for this treatment option. These criteria relate to both the willingness and the ability of the person to acquire the necessary knowledge of the operation and necessary measures to maintain a constant quality of therapy.
- Due to the fact that life-threatening complications such as peritonitis (inflammation of the peritoneum) can occur during peritoneal dialysis, each patient must be intensively trained before peritoneal dialysis. Following the knowledge transfer by the specially trained staff, the acquired knowledge is then reviewed. Among other things, the staff of a dialysis center must teach which hygiene measures are suitable and necessary. Only those who have completed the training with sufficient knowledge and feel confident in performing the procedure, may later independently perform the therapy measure in their own household.
- However, in addition to the willingness to learn, financial resources must be available to the necessary conversion. Also, the precise protocol to verify the correct implementation must be carried out conscientiously.
The procedures
Continuous ambulatory peritoneal dialysis (CAPD).
- CAPD represents the home dialysis procedure most commonly used by renal failure dialysis patients. Of critical importance to the function of the procedure are the bag changes required several times a day, which contain the dialysis fluid. Each bag change in home peritoneal dialysis is performed by the patient, resulting in a time requirement of 20 to 30 minutes per bag change. To achieve sufficient detoxification, the dialysate must remain in the peritoneal cavity (abdominal cavity) for approximately five hours.
- The volume applied per bag is usually two liters. For emptying the abdominal cavity through the subsequent outlet is used exclusively gravity.
- As a result of this principle of operation, the advantage is that by using this therapy and its continuous character, there are no pronounced volume changes in the water balance of the patient. In addition, consequently, abrupt electrolyte or toxin shifts can be avoided.
- With an optional add-on device, the patient has the option of postponing a bag change to nighttime. The patient connects to the prepared device in the evening, at a programmed time is now the valve opening to the outlet or inlet, respectively, which has the consequence that the patient has an undisturbed sleep phase.
- To further improve the detoxification performance (detoxification performance) it is possible to perform an additional bag change at night. However, so far there are no studies that a fifth change of dialysis fluid has a positive impact on the success of therapy.
Automatic peritoneal dialysis (APD)
- Automated peritoneal dialysis, which is increasingly displacing CAPD as a home dialysis procedure, performs significantly higher dialysis turnover than CAPD, with a volume of approximately twenty liters of fluid. This increase in volume is primarily due to the fact that APD is performed during the patient’s nocturnal sleep phase and the dialysate change is completely automated using a so-called cycler device.
- Furthermore, APD offers the advantage that, in contrast to CAPD, usually no more bag changes have to be performed during the day, so that the workload is noticeably reduced. The modern cycler devices of automatic peritoneal dialysis acting as the main component are characterized in particular by low-noise pumping systems, which leads to the fact that the normal sleep rhythm can be maintained.
- Furthermore, by using the APD can be ensured that the transport of the dialysis machine is easier and a low technical susceptibility to failure can be achieved. Furthermore, it should be noted that when using the APD, an increase in both dialysis performance and ultrafiltration rate (fluid removal) is generated.
- Due to the greater personal responsibility in home dialysis, the compliance (cooperative behavior of patients) of dialysis patients is basically promoted. However, the use of APD leads to better compliance than the use of CAPD, which is attributed to the fact that the acceptance is greater due to the improved suitability for everyday use. In addition, an increased acceptance among patients is observed, since especially their daily routine is not disturbed.
Further notes
- A meta-analysis on Korean patients suggests that peritoneal dialysis is associated with a higher mortality risk (risk of death) than hemodialysis in elderly patients.
