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

Disinfection of central venous access device needleless connectors: A human factors analysis

OBJECTIVE

Evidence-based central-line-associated bloodstream infection (CLABSI) prevention guidelines recommend the use of an antiseptic scrub to disinfect needleless connectors before device access. Guideline noncompliance may render disinfection ineffective. The goal of this study was to observe needleless-connector disinfection practices and to identify perceived facilitators and barriers to best practices of needleless-connector access.

METHODS

A human factors mixed-methods study involving nursing focus groups of perceived barriers and facilitators and clinical observations of compliance with instructions and protocols for use of 3.15% chlorhexidine gluconate/70% isopropyl alcohol (CHG/IPA) and 70% isopropyl alcohol (IPA) antisepsis products for central venous access device (CVAD) needleless-connector disinfection was conducted in intensive care units (ICUs) at 2 academic medical centers.

RESULTS

Access to the antiseptic product and lesser workload were identified as best-practice facilitators. Barriers were the time required per needleless-connector access and knowledge deficits. Of the 48 observed access events, 77% resulted in needleless-connector disinfection. The observed mean needleless-connector scrubbing times when using IPA were substantially below the recommended time. Drying time after product use was negligible.

CONCLUSIONS

Lack of access to the disinfection product, emergency situations, and high workload were barriers to needleless-connector disinfection. Observed scrubbing and drying times were shorter than recommended, especially for IPA wipes. These needleless-connector disinfection deficits may increase the risk of CLABSI. Ongoing education and periodic competency evaluation of needleless-connector disinfection, improvement of supply management, and staffing workload are required to imbed and sustain best practices. Further study involving a larger sample size in diverse patient populations is warranted.

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.

Positive and Neutral Needleless Connectors: A Comparative Study of Central-line Associated Bloodstream Infection, Occlusion, and Bacterial Contamination of the Connector Lumen

A pragmatic, multiphase prospective quality improvement initiative was performed to determine whether a positive displacement connector (PD) causes reduction of central line-associated bloodstream infection (CLABSI), occlusion, and catheter hub colonization when compared with a neutral displacement connector with alcohol disinfecting cap (AC). Patients with an active central vascular access device (CVAD) were enrolled March 2018 to February 2019 (P2) and compared to the prior year (P1). Two hospitals were randomized to use PD without AC (Hospital A) and with AC (Hospital B). Two hospitals utilized a neutral displacement connector with AC (Hospitals C and D). CVADs were monitored for CLABSI, occlusion, and bacterial contamination during P2. Of the 2454 lines in the study, 1049 were cultured. CLABSI decreased in all groups between P1 and P2: Hospital A, 13 (1.1%) to 2 (0.2%); Hospital B, 2 (0.3%) to 0; and Hospitals C and D, 5 (0.5%) to 1 (0.1%). CLABSI reduction was equivalent between P1 and P2 with and without AC, at around 86%. The rate of occlusion per lumen was 14.4%, 12.1%, and 8.5% for Hospitals A, B and C, D, respectively. Hospitals using PD had a higher rate of occlusion than those that did not (P = .003). Lumen contamination with pathogens was 1.5% for Hospitals A and B and 2.1% for Hospitals C and D (P = .38). The rate of CLABSI was reduced with both connectors, and PD reduced infections with and without the use of AC. Both connector types had low-level catheter hub colonization with significant bacteria. The lowest rates of occlusion were found in the group using neutral displacement connectors.

Assessment of Reflux From Needleless Connectors: Blinded Comparison of Category Designation to Benchtop Function Using a Venous Simulator

Needleless connectors (NCs) for vascular access have limited needlestick injuries, but complications including occlusion, thrombosis, and infections have increased despite reduced needlestick injuries. These complications relate to the ability of an NC design to limit volume fluctuations that can lead to fluid reflux with potential for microbial contamination. Different NC designs requiring specific usage protocols and training, a lack of clarity in NC function relative to manufacturer-designated categories, and confounding results from a limited number of studies comparing different NCs have resulted in confusion, ultimately leading to complications from undesirable fluid movement within the vascular access. The authors therefore quantified the magnitude of reflux with current commercially available NCs using a venous stimulator. Thirteen blinded NC designs spanning the categories of negative and positive displacement, neutral, and antireflux were tested to quantify fluid movement upon disconnection and reconnection from a representative intravenous pressure (3 NCs per design; 10 trials per NC). Trials for each NC tested followed consistent displacement trends leading to tight error bars. Blinded NCs were then characterized according to their function and compared with their category designation after unblinding. All positive and negative NCs functioned in a manner consistent with their respective category designations. Conversely, all NCs categorized as neutral actually functioned with negative displacement (ie, reflux upon disconnection; 4/5 NCs) or positive displacement (1/5 NCs). Only NCs classified as antireflux functioned as neutral, which was confirmed in a blinded bidirectional flow test. These results suggest that the neutral NC-marketed category may be confusing to users unless the particular NC design has an integrated antireflux component.

Clinical impact of needle-free connector design: A systematic review of literature

The objective of this systematic review is to analyze types of needle-free connectors and open systems and their effects on central line–associated bloodstream infection rates and other adverse outcomes through a research protocol consistent with the Preferred Reporting Items for Systematic Reviews’ recommendations. MEDLINE and Cochrane databases of systematic reviews were searched for relevant comparative studies published from January 2000 to September 2017. Eighteen studies compared central line–associated bloodstream infection (according to the Centers for Disease Control and Prevention/National Healthcare Safety Network definition), internal microbial contamination, occlusions, phlebitis, and other outcomes associated with needle-free connectors with a positive displacement device, negative displacement device, neutral displacement device, or three-way stopcock. Ten studies reported central line–associated bloodstream infection rates, which were lower with positive displacement devices versus negative displacement devices/neutral displacement devices (one study) and with negative displacement devices versus three-way stopcocks (three studies), but varied with different positive displacement device and negative displacement device/neutral displacement device designs (four studies). Seven studies reported internal microbial contamination rates, which were higher with three-way stopcocks versus negative displacement devices (two studies) and positive displacement devices (two studies), lower when positive displacement devices were used versus neutral displacement devices (one study), and varied with different types of negative displacement device (one study). Central line–associated bloodstream infection rates and most other outcomes analyzed were statistically significantly higher with three-way stopcocks (open devices) versus positive displacement device, negative displacement devices, and neutral displacement devices, but varied among closed device designs.

Needle-free connectors catheter-related bloodstream infections: a prospective randomized controlled trial

Background

In the critically ill, catheter-related bloodstream infection can result from bacterial contamination of infusion hubs of intravascular catheters. Needle-free connectors (NFC) have been suggested to reduce the rate of bacterial contamination and subsequent catheter-related bloodstream infection (CRBSI), but data remains ambiguous. Thus, we tested if a novel NFC would reduce bacterial contamination and subsequent CRBSI.

Results

In a prospective, randomized controlled trial, surgical ICU patients were randomized to three-way hubs closed by caps or Bionecteur® (Vygon, Inc.) of central venous catheters. Every 72 h, infusion lines were renewed and microbiological samples were taken. Bacterial growth was analyzed by blinded microbiologists. Incidence of bacterial contamination and CRSBI were assessed. Outcome parameters like length of stay on ICU and outcome were retrospectively assessed. Two thousand seven hundred patients were screened, 111 were randomized to the NFC, and 109 into the control group. Finally, 24 patients in the NFC and 23 control patients were analyzed. The majority of samples (NFC 77%; control 70%) found no bacterial growth. Coagulase-negative staphylococci were most commonly detected on CVC samples (NFC 17%; control 21%). We found CRBSI (defined as identical pathogens in blood culture and catheter line tip culture, and clinical manifestations of infection) in two control patients and one patient of the NFC group. Their length of ICU stay did not differ between groups (NFC 19 days; control 23 days).

Conclusion

The use of NFC does not influence the rate of bacterial contamination of infusion hubs of central venous catheters.

Trial registration

Clinicaltrials.gov, NCT02134769. Registered 09 May 2014.

The case for using a disinfecting cap for needlefree connectors

Catheter-related bloodstream infections (CRBSIs) are a signification cause of infection. When CRBSI rates are high, the cost to the patient and the organisation can be significant. More than ever before, there is a high demand for vascular access. Advances in treatment often entail extended indwell times for central vascular access devices. The care and maintenance of these devices is crucial in avoiding complications such as infection. Using care bundles in conjunction with other simple interventions, such as passive disinfecting caps, can help reduce CRBSI rates. The published evidence demonstrates that passive disinfecting caps can help reduce infection rates associated with different types of central venous catheters by protecting needlefree connectors from colonisation by pathogens and serving as a clear indicator that the line has been disinfected.

Needleless connector drying time-how long does it take?

Allowing needleless connectors (NCs) on vascular catheters adequate drying time after cleaning with antiseptic is essential. Drying time instructions on antiseptic pads/wipes relate to skin use, not inanimate objects. Needleless connector drying times after a 15-second scrub with isopropyl-alcohol, isopropyl-alcohol/chlorhexidine, or povidone-iodine varied from 5 seconds to >6 minutes.