NEEDLELESS CONNECTORS: NEW STANDARDS, STILL CONFUSING Matt Gibson, Chief Executive Officer for Vascular Access Consulting, LLC
How exciting it is to have the new Infusion Therapy Standards of Practice (SOP). One area of interest is needleless connectors (NC). Many clinicians find differentiating NCs and how to use them confusing.1 A common question I hear is, “What is the difference between neutral and anti-reflux NCs?” The way the SOP discusses these labeled connectors seems to be nearly the same. However, the labels come from the manufacturer’s marketing descriptions2, and there are no established quantitative criteria from device regulatory agencies that determine which device belongs to each category. The neutral NC is described in the SOP glossary3 as, “Contains an internal mechanism designed to reduce blood reflux into the vascular access device (VAD) lumen upon connection or disconnection.” This definition is different from the 2016 SOP4, where the term described as “internal mechanism to prevent blood reflux” which both definitions, 2016 and 2021, more closely describes the anti-reflux NC. Neutral, antireflux as well as negative connectors have a straight fluid pathway, but the anti-reflux is the only one that has an internal mechanism to reduce or prevent blood reflux. The differences between the anti-reflux technology and other NC categories are the volume of reflux (see Table 1) and bidirectional flow control5. When the vein’s pressure is higher than in the infusion system, the dome-shaped silicon diaphragm closes independent of the clinician dependent clamping. It will prevent the retrograde flow of blood into the catheter lumen and infusion system. More confusion with the glossary terms is with positive displacement NCs. The new SOP definitions tell us that the positive displacement NCs, having a complex fluid pathway, “Allows blood reflux on connection and disconnection.” This statement is a little confusing for the reader. As written, it implies that this type of connector refluxes, both when connection and disconnection occur. However, 15 | IQ | INTRAVASCULAR QUARTERLY NEWSLETTER
all NCs will only reflux during one phase of the connection-disconnection cycle6-8. Look at Table 1 (on following page). It is clear that all NCs reflux blood. The difference is when and how much occurs. Negative displacement, neutral and anti-reflux NCs reflux on disconnection, and positive NC reflux on connection. Generally, the neutral label connectors list less reflux than other first-generation negative connectors.
Why is this so important, you ask? Because up to 32 percent and 36 percent of catheters, PIVCs and CVCs, respectively, have occlusions9,10 leading to delays of treatment, increase risk of infection, catheter failure, and device replacement9,11-13. The SOP (36 B 1) states for neutral and anti-reflux connectors, “no specific sequence required” 3. This author’s opinion is that, this direction is not the best recommendation for connectors labeled as “neutral” considering the reflux volume listed for each NC (see Table 1). By not clamping the neutral NCs prior to disconnection will allow blood to reflux into the catheter. My recommendation is for end-users is to forget the idea that anything about the needleless connector is neutral. In the simplest of terms, all negative, neutral, and anti-reflux needleless connectors will reflux blood on disconnection. The difference is the volume. Clinicians will minimize reflux by engaging the clamp before disconnection occurs. CONTINUED ON NEXT PAGE
