An In Vitro Comparison of Microbial Ingress Into 8 Different Needleless IV Access Devices

Bacterial transfer and biofilm formation in needleless connectors in a clinically simulated in vitro catheter model

OBJECTIVE

Although needleless connectors (NCs) are widely used in clinical practice, they carry significant risk of bloodstream infection (BSI). In this study, we quantified differences in bacterial transfer and biofilm formation between various NCs.

DESIGN

Prospective, clinically simulated in vitro experimental study.

METHODS

We tested 20 NCs in a 5-day clinical simulation of Staphylococcus aureus inoculations onto NC septum surfaces, which were then flushed with saline and cultured for bacterial transfer. Biofilm formation was measured through destructive sampling of the connector-catheter system. Moreover, 8 NC design factors were evaluated for their influence on bacterial transfer and biofilm formation. This study was designed without a disinfection protocol to ascertain the intrinsic risk of each NC.

RESULTS

Clave Neutron and MicroClave had the lowest overall mean log density of bacteria in the flush compared to other NCs (P < .05), except there were no statistically significant differences between Clave Neutron, Microclave, SafeTouch, and SafeAccess (P ≥ .05). The amount of biofilm in the NC was positively associated with bacteria in the flush (P < .0005). Among 8 design factors, flow path was most important, with the internal cannula associated with a statistically significant 1 log reduction (LR) in bacteria in the flush (R2 = 49%) and 0.5-2 LR in the connector (R2 = 34%). All factors together best explained bacteria in the flush (R2 = 65%) and biofilm in the connector (R2 = 48%).

CONCLUSIONS

Bacterial transfer and biofilm formation in the connector-catheter system varied statistically significantly between the 20 NCs, suggesting that NC choice can lower the risk of developing catheter-related BSIs.

Peripheral intravenous catheter needleless connector decontamination study-Randomized controlled trial

BACKGROUND

Needleless connectors (NCs) were introduced to reduce health care work needlestick injuries (NSIs). If not decontaminated prior to use, NCs can be a portal for patient blood stream infections. The optimal disinfectant, and its application duration, for NC decontamination has not been empirically established.

METHODS

Factorial design randomized controlled trial comparing 70% isopropyl alcohol (IPA) and 2% chlorhexidine gluconate (CHG) in 70% IPA for 5, 10, or 15 seconds, in adult medical patients with peripheral intravenous catheters.

RESULTS

At baseline, 153 of 300 NCs (51%) grew microorganisms commonly found on the skin. Decontamination was successful in 150/153 (98%). There was no significant difference in decontamination between 70% IPA or 2% CHG in 70% IPA (P = .62), or decontamination for 5, 10, or 15 seconds (P = .21).

CONCLUSIONS

There was no difference in the effectiveness of 70% IPA and 2% CHG in 70% IPA for NC decontamination for peripheral intravenous catheters in the clinical environment. Successful decontamination was not different for applications of 5, 10, and 15 seconds; 15 seconds did not always remove all microorganisms. Factors such as cost, feasibility of compliance, and low risk of allergy support 5 seconds decontamination with 70% IPA as an acceptable approach.

The risk of microbial contamination associated with six different needle-free connectors

BACKGROUND

needle-free connectors are widely used in clinical practice. The aim of this study was to identify any differences between microbial ingress into six different connectors (three neutral-displacement, one negative-displacement and two anti-reflux connectors).

METHODS

each connector underwent a 7-day clinical simulation involving repeated microbial contamination of the connector's injection ports with Staphylococcus aureus followed by decontamination and then saline flushes through each connector. The simulation was designed to be a surrogate marker for the potential risk of contamination in clinical practice.

RESULTS

increasing numbers of S. aureus were detected in the flushes over the 7 days of sampling despite adherence to a rigorous decontamination programme. Significant differences in the number of S. aureus recovered from the saline flush of some types of connectors were also detected. Two different durations (5- and 15-second) of decontamination of the injection ports with 70% isopropyl alcohol (IPA) wipes were also investigated. There was no significant difference between the median number of S. aureus recovered in the saline flushes following a 5-second (165.5, 95% CI=93-260) or a 15-second decontamination regimen (75, 10-190).

CONCLUSIONS

The findings suggest that there may be differences in the risk of internal microbial contamination with different types of connectors and that even 15 seconds of decontamination may not fully eradicate microorganisms from the injection ports of some devices.

Outbreak column 19: needleless connectors (NCs) tales from nine outbreaks

A critical review of historical outbreak reports that are still influencing practice today is presented.  These outbreak reports were used as evidence in support of guideline recommendations and of the US Food and Drug Administration's (FDA) advisory notice requiring post-product surveillance for needleless connectors (NC) which have a positive displacement. Guideline recommendations were subsequently changed but not before other authorities had issued recommendations based on the original.  All the above led some purchasers to look for different NC designs.  The conclusions are that the evidence, as reported, does not support there being an increased risk from positive displacement NCs. Identified in this review were unsubstantiated claims, incompleteness in reporting of specifics, opinions considered as evidence and unexplored outbreak-provoking explanations.

Microorganisms present on peripheral intravenous needleless connectors in the clinical environment

The aim of this study was to quantify culturable microorganisms on needleless connectors (NCs) attached to peripheral intravenous catheters in hospitalized adult medical patients. Half (50%) of 40 NCs were contaminated with microorganisms commonly found on the skin or mouth. Staphylococcus capitis and Staphylococcus epidermidis were most commonly isolated. Emergency department insertion and higher patient dependency were statistically associated with positive NC microorganism growth. These results reaffirm the need for NC decontamination prior to access.

Microbiologic contamination of a positive- and a neutral- displacement needleless intravenous access device in clinical use

The use of a positive-displacement needleless intravenous access device was associated with lower microbial contamination rates compared with a neutral-displacement device when used on central venous catheters in hemato-oncology patients. In addition, rates of central line-associated bloodstream infection did not differ when either device was used.