Importance of Product Design on Effective Bacterial Removal by Fluid Convection in Y Set and Twinbag Systems

Abstract

The goal of this study was to quantitatively compare in vitro the ability of four commercially available peritoneal dialysis solution system designs to prevent the infusion of the most common accidental touch and airborne bacterial contaminant, Staphylococcus epidermidis, into the peritoneum using a total system evaluation approach. This approach took into consideration the number of system openings to the environment during an exchange combined with each system’s convective flushing characteristics. A Y set and a Twinbag system utilizing either an antimicrobial cap or a snap disconnect design for disconnection at the end of the solution exchange procedure were selected for study. The lowest peritoneal bacterial recovery count was seen with the antimicrobial cap system Twinbag, being significantly lower than any of the other systems tested (p < 0.0001). The highest bacterial recovery count occurred in the snap disconnect Y system, being significantly higher than any of the other products tested (p < 0.0001). Both the antimicrobial cap systems permitted infusion of fewer bacteria than the snap disconnect systems, despite being inoculated with larger numbers of bacteria to account for a potential additional opening of the system, during the disconnect procedure. This evaluation emphasizes the importance of fluid path flow design in the overall safety performance of peritoneal dialysis systems.