Contrib Nephrol. Basel, Karger, 2019, vol 197, pp 9–16 (DOI: 10.1159/000496302)
______________________
Evolution of Automated Peritoneal Dialysis Machines
Anna Giuliania · Carlo Crepaldia · Sabrina Milan Manania · Sara Samonia · Manuela Cannonea · Massimo De Cala, b · Claudio Roncoa–c
aDepartment of Nephrology, Dialysis and Transplantation, San Bortolo Hospital, Vicenza, Italy; bInternational Renal Research Institute of Vicenza (IRRIV), Vicenza, Italy; cUniversity of Padova, Padova, Italy
______________________
Abstract
Peritoneal dialysis (PD) has undergone several improvements over the years. Among the numerous advances, we may recall the improvement in the quality of fluids, safety of catheters and connections, knowledge of the peritoneal membrane in the process of mass transfer separation typical of PD. In parallel with these achievements, PD techniques have also displayed significant improvements mainly due to the evolution of machines and cyclers. Originally, bottles or containers were used to deliver and drain fluid to and from the peritoneal cavity by gravity using manual techniques. Subsequently, the development of semiautomatic or automatic machines have permitted to deliver an adequate treatment during night-time without the need of patient or care giver intervention. These advances solved the problem of treatment delivery, but other aspects including complications and adherence to prescription could only be managed using magnetic cards containing data from different treatments and brought by the patient at the following routinely planned hospital consultation. Today these limitations have been overcome by the new cycler “HOMECHOICE CLARIA” equipped with SHARESOURCE software featuring a bidirectional communication protocol that allows a full remote patient management (RPM). RPM has demonstrated significant advantages including higher technique survival, reduced rate of complications, and reduced costs in patients undergoing long-term PD.
© 2019 S. Karger AG, Basel
Introduction
The utilization of automated peritoneal dialysis (APD) increased progressively from its original application, reaching 45% of the cases in 2008 in developed countries [1]. In Italy in 2016, it has been reported in 50% of patients treated by PD [2]. This represents a consequence of continuous evolution of PD cyclers. Since the first description by Boen et al. [3, 4] in the early 1960s, PD cyclers have undergone significant improvements making APD a fast-growing modality for renal replacement therapy (Fig. 1). The success of APD derives from multiple factors. Automation has permitted to overcome some of the limitations of continuous ambulatory PD (CAPD), and has led to optimized management of ultrafiltration (UF) failure, achievement of adequate dialytic clearances in anuric patients, and avoidance of poor patient compliance. Moreover, APD is the preferred modality in young patients and in those with an active life, since it allows to be free from dialysis during the daytime. On top of these factors, technological improvement of cyclers was undoubtedly the most determinant element in the growth of APD. The ability of modern cyclers to deliver accurate and reliable treatments made APD a real alternative to CAPD. In the decade between 1970 and 1980, specific improvements were carried out in the hardware, moving from manual techniques to semi-automatic cyclers. Subsequently, automatic cyclers were designed for hospital use, capable of preparing the dialysis solution from tap water and liquid concentrates. More recently, in the 1990s, continuous progresses in the hardware component led to the availability of portable cyclers, suitable for home treatment. Further evolution regarded the user interface and software design. In particular, the use of memory magnetic cards made it possible to effectively control prescription, delivery and monitoring of different APD modalities. Furthermore, patient’s card allowed to record treatments at home and review the adherence of patients when they were brought to the hospital for periodic consultation. Nowadays modern cyclers allow bidirectional communication between hospital and patient’s home, through a cloud-based platform. This real-time monitoring represents an important component of telemedicine in the field of PD and allows for a true remote patient management (RPM) in out-of-hospital treated populations where medical surveillance remains essential.
Origin of APD
The first application of PD was in 1959 by Morton Maxwell. He set up a rudimental system to deliver fluids into abdomen, which can be considered the forerunner of the modern CAPD. The system consisted of two 1 L bottles, filled with warm dialysis solutions, connected through a Y tube, to the catheter. The bottles were hung above the bed, to allow the dialysis fluids to flow by gravity into the abdomen. After 1 h dwell time, the bottles were lowered into the floor and used for drainage. This procedure was repeated for 12–36 h and was performed manually. The maneuver of changing bottles requires multiple disconnections of the system, representing the major risk of touch contamination. To overcome this complication, containers of 10 L were subsequently used both for load and drain phases, significantly reducing the number of connections.
Fig. 1. Evolution of PD cyclers from origin to today. PD, peritoneal dialysis; APD, automated PD; IPD, intermittent PD; CCPD, continuous cyclic PD.
In 1962 in Seattle, Boen et al. [3, 4] conceived the first cycler able to deliver and drain fluids into and from the abdomen, semi-automatically. Dialysis fluids were prepared in the University pharmacy and stored in 40 L containers and periodically shipped to patient’s home. The fluids were pumped into an elevated reservoir, filled up to 2 L, and from there, moved to peritoneal cavity simply by gravity. Inflow, dwell, and outflow were regulated by a timer, which controlled clamps. Therapy was intermittent, performed once a week, over 20–22 h/session. The advantage of this semi-automatic technique, compared to the manual paired bottles, was the reduction of the number of connections and therefore the risk of touch contamination. Subsequently, smaller plastic containers (10 L) were connected in series for a closed-circuit PD.
In 1966, Lasker designed the first “PD cycler.” It featured 4 bottles of dialysis solution to obtain a reservoir of 8 L, connected to pre-sterilized disposable tubings and bags. This concept of semi-automatic machine was then applied to many other cyclers with few variations. In principle, a pump was moving fluid to fill a 2 L bag suspended above the patient and then inflow and outflow into and from the abdomen was operated by gravity.
The next step in automatization was to design a machine able to produce sterile dialysate directly at patient’s home, avoiding transport of large amount of fluids. At the end of 1960, Tenckhoff created a system able to purify cold tap water by reverse osmosis to be mixed with a liquid concentrate of glucose and electrolytes. The automatic cycler allowed the production of large amounts of safe and sterile dialysate, but it was bulky and costly. In 1970s, semi-automatic machines were mostly used in Europe, while automatic equipment was preferred in USA where 10 L tanks were not available.
Both semi-automatic and automatic machines began the era of APD and were mostly used in the hospital setting for intermittent PD, also defined nightly intermittent PD. With the advent of CAPD in the 1970s, the use of the machine was partially abandoned. CAPD was easier than APD and patients could manage treatment by themselves