Microbicidal efficacy of povidone-iodine in a noncontact manner applied to a continuous ambulatory peritoneal dialysis connection system.

In peritoneal dialysis (PD) the dialysate is introduced into the peritoneal cavity, and the peritoneal membrane is used as the dialysis membrane. In PD, patients exchange the dialysate by themselves through the connection tube attached to the indwelling catheter that is inserted into the peritoneal cavity. Microbes may enter the peritoneal cavity during dialysate exchange, and, therefore, peritonitis is a potential complication of PD. To prevent microbial contamination, the connection tube tip is generally sealed with a protection cap containing povidone-iodine (PVP-I) during the dwelling time. This cap is designed to make direct contact with the tube tip so that microbes attached during dialysate exchange are killed by the next dialysate exchange. However, if excess PVP-I flows into the peritoneal cavity and is absorbed into the body, the complications, including thyroid dysfunction, peritoneal inflammation, and fibrous thickening, can develop. Therefore, in this study, a new manual connection system (Zero System, JMS Co., Ltd., Hiroshima, Japan) for continuous ambulatory peritoneal dialysis was investigated to confirm that the PVP-I solution within the protection cap of the new system would not flow into the fluid passing through the tube. An experiment was also performed to confirm that the microbes on the connector tip become completely nonviable after attachment of the cap for 3 hours. The cap is fitted with a sponge containing a 10% PVP-I solution, the same as for the conventional cap system. However, the system is designed to achieve disinfection without contact, unlike with the conventional system, in which disinfection is achieved by direct contact of the PVP-I-containing sponge with the open end of the attached connector. The test results demonstrated that adequate disinfection with this system can be achieved by the next exchange, while avoiding entry of PVP-I into the peritoneal cavity from the cap. The results suggest that the use of this connection system can avoid adverse reactions arising from the absorption of PVP-I and prevent the onset of peritonitis caused by microbial invasion of the peritoneal cavity.

A comparative study of sterility levels in continuous ambulatory peritoneal dialysis system.

INTRODUCTION: Peritonitis remains a serious risk associated with continuous ambulatory peritoneal dialysis (CAPD), although better patient education programs and such technological advances as improved automated connecting devices have greatly decreased its incidence over the past 20 years. The automated devices have a good resistance to contamination, but they rely on an external electrical power source and are not easily portable. There has, therefore, been a need for a highly sterile nonelectric manual connecting device to complement the automated devices already in use. Such a manual device has recently been developed. We compared the level of sterility after touch contamination in this new device with levels in 2 other connecting devices: a conventional device with a manual cap (JMS Co. Ltd., Hiroshima, Japan), and a powered total containment device (JMS Co. Ltd.). METHOD: Five bacteria frequently causing CAPD-related peritonitis (Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, Pseudomonas aeruginosa, and Candida albicans) were separately applied to the tip of each connecting device, and peritoneal washing fluid was injected as in a routine exchange. We used a membrane filter method to determine whether the route had been contaminated by the washing fluid. RESULTS: In the conventional device with a manual cap, 3 to 4 colony-forming units (CFUs) of S. aureus were detected in 2 of 10 drainage samples, 8 CFUs of E. coli in 1 of 10 drainage samples, and 1 CFU of E. coli in the injection fluid. In contrast, no contamination was detected in the automated connecting device or the new manual cap device. CONCLUSION: This study confirmed that the new device has a risk of touch contamination lower than that of the conventional manual cap device and equal to that of the automated device. Being easily portable and not reliant on an external power source, the new device should be useful in various situations.