We present a protocol to show the installation of a needle-free connector with positive displacement on a central venous catheter.
Needle-free connectors were initially designed and promoted to avoid blood exposure for healthcare workers. Some recent data suggest that the latest generation of connectors (with positive displacement) may be of interest for reducing central venous line infections. We have been using needle-free connectors for several years in our intensive care unit and here we present a protocol for installing these connectors on central venous catheters. After insertion of the catheter and control of the permeability of the lines, the connectors must be purged with 0.9% NaCl before being connected. The connectors replace all disposable caps used on infusion stopcocks and manifolds. All the connectors are changed every 7 days as recommended by the manufacturer (except when there is macroscopic contamination, which requires an immediate change of the connector). Before each injection, the connector must be disinfected for at least 3 seconds with 70% isopropyl alcohol. The connectors must not be disconnected (unless changed), as the injection is done through the device. Setting up the connectors slightly increases the total time required to place the catheter and there is no formal evidence that these connectors reduce the incidence of infectious or thrombotic complications. However, these devices simplify the management of central venous lines and prevent the catheter circuit from "opening" once it has been sterilely installed.
Central venous catheter-related infections (CRI) are a severe complication of central venous catheters in intensive care unit (ICU). The decline in CRI remains an ever-present objective, with a final goal of "zero catheter related infection"1. Needle-free connectors were initially designed and promoted to avoid blood exposure for healthcare workers. There are two main designs of connectors: split septum (no internal moving parts) and closed valve systems (internal moving components) but both designs can be combined in one connector2. Needle-free connectors are categorized according to the type of fluid displacement that occurs after disconnection of a male Luer valve: negative (blood reflux into the catheter), neutral, and positive (with a push of blood out of the catheter lumen)2,3.
Some connectors have been described as a cause of catheter-related infections, in particular in the intensive care unit (ICU)4,5,6. A new generation of needle-free connectors with minimal internal complexity, a reduction or elimination of interstitial or dead space, a visible fluid path to help assess proper flushing technique, and a flat access surface, etc. has been designed to lower the risk of infection. In vitro, these connectors have shown low bacterial colonization7. There are global recommendations from the laboratory manufacturing these connectors; however, there is no practical description of how to install them on catheters8. Hence, it is possible that each team uses them differently. Therefore, we propose a formalized protocol for the installation of these connectors on central venous lines in the ICU.
We present the installation of a positive pressure needleless connector (PPNC) with an internal silicone piston in our ICU but this protocol is applicable with any positive displacement valve. This valve is a mechanical needle-free connector with positive displacement.
1. Preparation of connectors and infusion lines
2. Placement of the catheter
3. Installation of the connectors
4. Use of connectors and infusion lines
5. Replacement and maintenance of connectors and infusion lines
Once all the elements are in place, the catheter has connectors on almost all the junctions between two infusion lines (Figure 1). Thus, it has proximal connectors on each line and two connectors on the sockets of the 3-way extensions (Figure 2). Each infusion line has connectors at all its female sockets (Figure 3). Once the assembly is in place, any injection or infusion (continuous or discontinuous) must be made, after disinfection, through one of the connectors of the infusion lines or extensions (Figure 4).
Maintaining the connectors in place keeps the infusion system closed as well as sterile mounted and minimizes the risk of bacterial contamination. One of our previous works, the first study that prospectively analyzed these devices over several years, showed a significant decrease in CRI incidence during the six-year period framing the introduction of the connectors (Figure 5)10. In this work, the incidence of CRI before using connectors was 6.2 CRI/1000 catheter-day vs. 2.7 CRI/1000 catheter-days after using connectors10. Moreover, we did not find any increase of CRI after the beginning of connector use (Figure 5) and there was no significant difference concerning the kind of bacteria species involved in CRI10. We have not identified any specific complications associated with the use of these connectors during these years of use.
Figure 1: Global view of the catheter once the connectors have been placed. Please click here to view a larger version of this figure.
Figure 2: Proximal part of the catheter with proximal connectors (A) and connectors on the 3-way extension stopcock (B). Please click here to view a larger version of this figure.
Figure 3: 4-port manifold with connectors. Please click here to view a larger version of this figure.
Figure 4: Steps of injection through a connector. (A) Disinfect the surface of the connector for 3 seconds with 70% isopropyl alcohol. Wait until the connector is dry. (B) Insert the tip of the syringe or infuser into the connector. (C) Inject or infuse the medication. (D) Remove the syringe or infuser. Please click here to view a larger version of this figure.
Figure 5: Evolution of catheter-related infection incidence before and after the use of connectors. Figure taken from Clavier et al.10 Please click here to view a larger version of this figure.
Setting up the connectors slightly increases the total time required to place the catheter. However, their use has several advantages: no need to maintain a continuous saline perfusion for non-infused lines, rapid stopping of infusion of the lines if necessary (in case of urgent transport of the patient for example), no need to use single-use caps several times a day to close the infusion lines. The use of connectors simplifies the daily use of catheter infusion lines without any particular complications. It should be noted that during our four year experience of these PPNC connectors there have been no complications with rapid fluid administration while this has been described with other types of connectors11. It is essential to maintain complete asepsis when installing the connectors in order to keep the infusion system closed. In addition, regular examination of the connectors for contamination is essential to be able to rinse or change the implicated connectors and avoid bacterial growth. A recent work reports the in vitro efficacy of a pulsative flushing technique to prevent bacterial colonization of vascular access devices but this technique has not been evaluated directly on needleless connectors12. Due to the technical aspect of this kind of connector, nurses must be trained before using these connectors in everyday practice. In this context, the use of Aseptic Non Touch Technique, which is a safe method for managing intravascular devices, is very relevant13. Thus, even after the connectors are set up, direct contact with the connectors should be minimized as much as possible to minimize the risk of contamination. In this context, the use of a disinfectant cap on needleless connectors can help to limit the contact with connectors and is effective in reducing central line-associated bloodstream infections14.
The inclusion of extension tubing, stopcocks and manifolds increase the complexity of the system and expose it to a risk of contamination of stopcocks and manifolds15. Our choice of extensions and infusion lines is the result of a reflection on the balance between patient safety and infectious risk. In the ICU, continuous uninterrupted infusion of certain drugs is essential (e.g., catecholamine, sedation). In our protocol, the use of a 3-way extension stopcock allows medication relays to be easily made without ever interrupting the infusion, which is a guarantee of safety for the patient. The use of a unique 4-port manifold with a perfusion line allows the infusion of several drugs simultaneously (e.g., antibiotics, analgesics, insulin) but the number of these manifolds should be limited to prevent the risk of infection.
Some studies have shown interest in a closed system to prevent colonization and catheter infections16,17. Additionally, several studies have reported a decrease in catheter infection after using PPNCs10,18,19. It is also possible that these connectors may decrease thrombotic catheter occlusions, but there is insufficient evidence to conclude a direct causal link between needleless connectors and catheter occlusions20,21. Moreover, data in the literature support the safe and prolonged use of these devices10,16,19. However, different department may sometimes use different methods to mount connectors on infusion lines and most studies do not describe the method used to install connectors on catheters. It could appear interesting that studies on connectors report their installation protocol to better assess potential differences of practice between teams.
The authors have nothing to disclose.
The authors are grateful to Nikki Sabourin-Gibbs, Rouen University Hospital, for her help in editing the manuscript. The authors would like to thank the communication department of Rouen University Hospital and the teams of the Medical Training Center for their participation in the video shoot.
BD MaxZero™ needle-free connector | Becton Dickinson | MZ1000-07 | we present the installation of the connector with MaxZero but this protocol is applicable with any positive displacement valve. |
4-port mannifold with PE/PVC extension | Cair-LGL | RPB4310A | |
PE/PVC extension line with 3-way stopcock | Cair-LGL | PE3302M | |
NaCl 0.9% 250 ml | Baxter | 2B1322 | |
BD Plastipak™ 50mL Luer-Lock Syringe | BECTON DICKINSON MEDICAL | 613-3925 |