Needleless connectors provide needle-free access to vascular access devices, helping protect healthcare workers from needlestick injuries. Their design can also influence two important catheter complications: occlusion and bloodstream infection.
How Connector Design Matters
NCs generally fall into two categories:
- Split-septum connectors: Use a self-sealing septum and provide a relatively direct fluid pathway with no internal moving parts.
- Mechanical valve connectors: Use an internal valve mechanism and may have negative, positive, neutral, or anti-reflux displacement characteristics.
One key difference is fluid displacement. When a connector allows blood to reflux into the catheter, fibrin and thrombus can accumulate and contribute to occlusion.
Occlusion and Blood Reflux
Reducing blood reflux may help maintain catheter patency. Studies have reported lower occlusion rates with anti-reflux connectors, while other research has found differences in occlusion rates between positive and neutral displacement connectors.
Because blood reflux can contribute to thrombus formation, connector selection and proper flushing are important parts of maintaining catheter patency.
Infection Risk
The connector is also a potential entry point for microorganisms. Connector design, surface characteristics, and disinfection techniques can all affect the risk of contamination and biofilm formation.
The CDC notes that a split-septum valve may be preferred over some mechanical valves because of increased infection risk associated with certain mechanical valves. Research has also demonstrated differences between connector designs in bacterial transfer and biofilm formation.
A connector with a smooth, solid external surface and minimal gaps or crevices may also make thorough disinfection easier.
The Occlusion–Infection Connection
Occlusion and infection can be closely related. Blood reflux can promote both thrombus formation and an environment that supports microbial growth. Fibrin and biofilm can accumulate within the catheter, contributing to both loss of patency and infection risk.
This makes connector design an important consideration, not only for maintaining catheter function, but also for supporting infection prevention strategies.
What to Look For in a Needleless Connector
When evaluating NCs, consider features such as:
- Low or minimal fluid displacement to help reduce blood reflux
- Simple internal design with minimal dead space
- Smooth, solid external surfaces that can be thoroughly disinfected
- A direct fluid pathway that supports effective flushing
- Evidence-based performance for catheter patency and infection prevention
Best Practices Still Matter
Connector design is only one part of the equation. Consistent disinfection before every access, proper flushing, and staff education remain essential to maintaining catheter patency and reducing infection risk.
Needleless connector design can influence both catheter patency and infection risk. Understanding fluid displacement, internal architecture, and external surface design can help clinicians make informed connector choices. Combined with proper disinfection, flushing, and handling practices, selecting an appropriate needleless connector can support safer and more reliable vascular access.
Explore our range of vascular access solutions. Our portfolio allows clinicians to choose the appropriate device for the level of care required. Please contact us today for more information about our products and for a custom quotation.
Health Line International Corp. is not responsible for any errors, omissions, injury, loss, or damage arising from or relating to the use (or misuse) of any information, statements, or conclusions contained in or implied by the contents of this document or any of the source materials. This content is not intended to replace professional medical advice.
References
Nickel, B. et al., (2024, January/ February) Infusion Therapy Standards of Practice 9th edition. Journal of Infusion Nursing. https://www.ins1.org/publications/infusion-therapy-standards-of-practice/
Leskovar, B. et al., (2026, January 16) Needle-free connectors in tunneled central venous catheters for hemodialysis: A prospective single-centre safety and feasibility study. National Library of Medicine. https://pmc.ncbi.nlm.nih.gov/articles/PMC12914504/
Centers for Disease Control and Prevention. (2024, February 28) Background Information: Strategies for Prevention of Catheter-Related Infections in Adult and Pediatric Patients. CDC. https://www.cdc.gov/infection-control/hcp/intravascular-catheter-related-infection/prevention-strategies.html
Sansalone, A. et al., (2023, May 24) Needle-free connectors to prevent central venous catheter occlusion at a tertiary cardiac center: A prospective before and after intervention study. National Library of Medicine. https://pubmed.ncbi.nlm.nih.gov/34396802/
Rosenthal, V. (2020, November 21) Clinical impact of needle-free connector design: A systematic review of literature. National Library of Medicine. https://pubmed.ncbi.nlm.nih.gov/32056487/
Koeppen, M. et al., (2019, December 2) Needle-free connectors catheter-related bloodstream infections: a prospective randomized controlled trial. National Library of Medicine. https://pmc.ncbi.nlm.nih.gov/articles/PMC6888779/
Curran, E. (2016, July 25) Needleless connectors: the vascular access catheter’s microbial gatekeeper. National Library of Medicine. https://pmc.ncbi.nlm.nih.gov/articles/PMC5102078/