Key messages
• People with kidney failure (a condition where a person's kidneys no longer function well enough to keep them alive) require some form of kidney replacement therapy to sustain life. Dialysis aims to mimic native kidney function by removing solutes, toxins, and excess fluid. One type of dialysis, peritoneal dialysis, uses the lining of the abdomen to remove waste products from the blood by using a solution that is added to the abdomen to absorb any waste and excess fluid. We compared automated peritoneal dialysis (automatic delivery of the solution by a machine) to continuous ambulatory peritoneal dialysis (manual delivery of the solution).
• We are very uncertain about the benefits or harms of automated peritoneal dialysis compared to continuous ambulatory peritoneal dialysis in people with kidney failure. We found only two studies with 131 patients.
• Larger, well-designed studies are needed to determine the potential benefits of automated peritoneal dialysis over continuous ambulatory peritoneal dialysis. Future research should focus on important patient outcomes, such as quality of life and their ability to participate in normal daily living such as work, study, and recreational and social activities.
What is peritoneal dialysis?
Kidney failure is a condition where a person's kidneys no longer function well enough to keep them alive. Kidney replacement therapy, in the form of dialysis or transplantation, is required to sustain life. Dialysis aims to remove solutes, toxins, and fluid from patients with kidney failure, trying to mimic native kidney function. Peritoneal dialysis is one type of dialysis which uses the lining of the abdomen – called the peritoneal membrane – to remove waste products from the blood. It is usually done at home and can even be carried out while sleeping. During peritoneal dialysis, a fluid called a dialysis solution passes into the abdomen through a tube called a catheter, which has been surgically inserted. Once the dialysis fluid has flowed into the abdomen, it then stays there for between one and six hours, cleaning the blood by absorbing any waste and excess fluid. The dialysis solution containing the waste and excess fluid is then drained out of the abdomen through the catheter. This dialysis solution can be delivered automatically by a machine (automated peritoneal dialysis) or manually using gravity to fill and empty the abdomen (continuous ambulatory peritoneal dialysis).
What did we want to find out?
We wanted to find out whether automated peritoneal dialysis was better than continuous ambulatory peritoneal dialysis in terms of the number of deaths, hospitalisations, infections, the need to change to another form of dialysis, catheter removal, too much water in the body, blood pressure, complications such as fluid leaking from the catheter, residual kidney function (the remaining ability of the kidneys to excrete water and toxins) and quality of life.
What did we do?
We searched for studies that compared automated peritoneal dialysis with continuous ambulatory peritoneal dialysis in people with kidney failure. We compared and summarised the results of the studies and rated our confidence in the evidence based on factors such as study methods and sizes.
What did we find?
We found two studies (published in 1994 and 1999) which included a total of 131 people with kidney failure. The largest study included 97 people, and the smallest study included 34 people. The studies were conducted in Denmark and the Netherlands. One study lasted six months, and one study lasted 24 months.
Based on existing research, we are uncertain whether automated peritoneal dialysis offers advantages over continuous ambulatory peritoneal dialysis for any of our outcomes of interest.
What are the limitations of the evidence?
Our confidence in the evidence is low to very low, and the results of future research could differ from the results of this review. The small number of studies, the small number of people included, and the short duration of the studies were the major limitations.
How up to date is this evidence?
The evidence is up-to-date to August 2024.
Insufficient evidence exists to decide between APD and CAPD in kidney failure patients with regard to clinical and patient-reported outcomes. Therefore, current evidence is insufficient as a guide for clinical practice. Given that the sample sizes of existing studies are generally small with insufficient follow-up, there is a need for large-scale, multicentre studies. Future research should focus on possible differences between APD and CAPD in residual kidney function, euvolaemia, and patient-reported outcomes such as HRQoL, symptoms, patient satisfaction and life participation.
Peritoneal dialysis (PD) is a home-based kidney replacement therapy (KRT) performed in people with kidney failure. PD can be performed by manual filling and draining of the abdominal cavity, i.e. continuous ambulatory PD (CAPD), or using a device connected to the PD catheter that is programmed to perform PD exchanges, i.e. automated PD (APD). APD is considered to have several advantages over CAPD, such as a lower incidence of peritonitis, fewer mechanical complications, and greater psychosocial acceptability. Acknowledging the increasing uptake of APD in incident and prevalent patients undergoing PD, it is important to re-evaluate the evidence on the comparative clinical and patient-reported outcomes of APD compared to CAPD. This is an update of a Cochrane review published in 2007.
To compare clinical and patient-reported outcomes of APD to CAPD in people with kidney failure.
In this update, we searched the Cochrane Kidney and Transplant Register of Studies until 29 August 2024. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Registry Platform (ICTRP) Search Portal, and ClinicalTrials.gov.
Randomised controlled trials (RCTs) comparing APD with CAPD in adults (≥ 18 years) with kidney failure.
Two authors independently screened the search results and extracted data. Data synthesis was performed using random-effects meta-analyses, expressing effect estimates as risk ratios (RR) with 95% confidence intervals (CI) for dichotomous data and mean differences (MD) with 95% CIs for continuous data. Certainty in the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.
Two RCTs (131 randomised people) comparing APD with CAPD were included in this update. One RCT had a follow-up of six months, and one RCT had a follow-up of 24 months. The risk of bias in the included studies was mostly low, except for the high risk of performance bias for subjective outcomes.
The evidence is very uncertain about the effect of APD compared to CAPD on death, hospitalisations, PD-related peritonitis, change of dialysis modality, residual kidney function, health-related quality of life (HRQoL), overhydration, blood pressure, exit-site infections, tunnel infections, mechanical complications, PD catheter removal, or dialysis adequacy measures. These results were largely based on low to very low certainty evidence; hence, caution is warranted when drawing conclusions.