An In Vitro Evaluation and Comparison of Commercially Available Needleless Connectors with and Without Anti-Reflux Technology

Abstract

Design, function, and performance vary between negative displacement, positive displacement and pressure-activated antireflux needleless connectors (NCs). Marketing terms used to classify needleless connectors do not adequately describe function and performance, leading to confusion and poor understanding of the correct flush-clamp-disconnect sequence specific to each NC design. We compared commercially available NCs without integrated anti-reflux technology to their exact design counterpart with anti-reflux technology. The goal of this study was to evaluate each NC's ability to control bi-directional fluid movement caused by mechanical and physiological pressure changes and measure reflux volume. A venous simulator was used to measure and visualize fluid displacement associated with each NCs design upon connection and disconnection of a syringe. A bi-directional flow test was also performed by creating a pressure gradient between two reservoirs which were connected using the NC being tested. The fluid displacement at syringe disconnection was negative for all devices tested. All NCs with integrated anti-reflux technology significantly reduced the reflux volume compared to their design counterparts without anti-reflux technology (P < .0001). The difference in reflux volume was statistically significant (P < .0001) between all NC devices with integrated anti-reflux technology (0.27µL; 95% CI 0.21-0.34µL) compared to all devices without anti-reflux technology (4.15µL; 95% CI 3.76-4.54µL). All NCs without anti-reflux technology failed to demonstrate the ability to control blood reflux and bi-directional fluid movement. These results demonstrate that integrated anti-reflux technology is effective at preventing blood reflux caused by mechanical and physiological pressure changes in a closed IV system.