Microbiological evaluation of central venous catheter administration hubs

Challenges in reducing the risk of infection when accessing vascular catheters

Injection safety is essential to reduce the risk of healthcare-associated infections (HAIs) when accessing vascular catheters. This general review evaluates the contamination of vascular catheter access ports and associated HAIs in acute care settings, focusing on open lumen stopcocks (OLSs) and disinfectable needleless closed connectors (DNCCs). PubMed was searched from January 2000 to February 2021. OLS intraluminal surfaces are frequently contaminated during patient care, increasing the risk of HAIs, and neither an isopropyl alcohol (IPA) pad nor a port-scrub device can reduce contamination effectively. In contrast, DNCCs can be disinfected, with most studies indicating less intraluminal contamination than OLSs and some studies showing decreased HAIs. While the optimal DNCC design to reduce HAIs needs to be determined, DNCCs alone or stopcocks with a DNCC bonded to the injection port should replace routine use of OLSs, with OLSs restricted to use in sterile fields. Compliance with disinfection is essential immediately before use of a DNCC as use of a non-disinfected DNCC can have equivalent or greater risk of HAIs compared with use of an OLS. The recommendations for access port disinfection in selected national and international guidelines vary. When comparing in-vitro studies, clinical studies and published guidelines, consensus is lacking; therefore, additional studies are needed, including large randomized controlled trials. IPA caps disinfect DNCCs passively, eliminate scrubbing and provide a contamination barrier; however, their use in neonates has been questioned. Further study is needed to determine whether IPA caps are more efficacious than scrubbing with disinfectant to decrease HAIs related to use of central venous, peripheral venous and arterial catheters.

Practice Guidelines for Central Venous Access 2020

These practice guidelines update the Practice Guidelines for Central Venous Access: A Report by the American Society of Anesthesiologists Task Force on Central Venous Access, adopted by the American Society of Anesthesiologists in 2011 and published in 2012. These updated guidelines are intended for use by anesthesiologists and individuals under the supervision of an anesthesiologist and may also serve as a resource for other physicians, nurses, or healthcare providers who manage patients with central venous catheters.

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Antisepsis in the handling of vascular access connections

Needleless connectors provide easy access points to the vascular system for the administration of fluids, avoiding the risk of accidental punctures and increasing safety in vascular access manipulation. Non-aseptic manipulation can favor contamination, turning connectors into the penetration route for endoluminal contaminants with the capacity of triggering infectious complications, with serious consequences for the patient. Considering catheter-related bacteremia as a serious and avoidable adverse effect, prevention programs should incorporate measures to combat predisposing factors, such as improved staff training, the safe design of devices, improved disinfection procedures, and optimized antiseptic use. Monitoring adherence to safe practices and reporting results are important to promote understanding of the risks and benefits of decontaminating connections and thus to improve patient safety. safety. This article is part of a supplement entitled "Antisepsis in the critical patient", which is sponsored by Becton Dickinson.

Disinfection of Needleless Connector Hubs: Clinical Evidence Systematic Review

Background. Needleless connectors (NC) are used on virtually all intravascular devices, providing an easy access point for infusion connection. Colonization of NC is considered the cause of 50% of postinsertion catheter-related infections. Breaks in aseptic technique, from failure to disinfect, result in contamination and subsequent biofilm formation within NC and catheters increasing the potential for infection of central and peripheral catheters. Methods. This systematic review evaluated 140 studies and 34 abstracts on NC disinfection practices, the impact of hub contamination on infection, and measures of education and compliance. Results. The greatest risk for contamination of the catheter after insertion is the NC with 33-45% contaminated, and compliance with disinfection as low as 10%. The optimal technique or disinfection time has not been identified, although scrubbing with 70% alcohol for 5-60 seconds is recommended. Studies have reported statistically significant results in infection reduction when passive alcohol disinfection caps are used (48-86% reduction). Clinical Implications. It is critical for healthcare facilities and clinicians to take responsibility for compliance with basic principles of asepsis compliance, to involve frontline staff in strategies, to facilitate education that promotes understanding of the consequences of failure, and to comply with the standard of care for hub disinfection.

Effect of Nurse Staffing and Antimicrobial-Impregnated Central Venous Catheters on the Risk for Bloodstream Infections in Intensive Care Units

Background:

Defining risk factors for central venous catheter (CVC)-associated bloodstream infections (BSIs) is critical to establishing prevention measures, especially for factors such as nurse staffing and antimicrobial-impregnated CVCs.

Methods:

We prospectively monitored CVCs, nurse staffing, and patient-related variables for CVC-associated BSIs among adults admitted to eight ICUs during 2 years.

Results:

A total of 240 CVC-associated BSIs (2.8%) were identified among 4,535 patients, representing 8,593 CVCs. Antimicrobial-impregnated CVCs reduced the risk for CVC-associated BSI only among patients whose CVC was used to administer total parenteral nutrition (TPN, 2.6 CVC-associated BSIs per 1,000 CVC-days vs no TPN, 7.5 CVC-associated BSIs per 1,000 CVC-days;P= .006). Among patients not receiving TPN, there was an increase in the risk of CVC-associated BSI in patients cared for by “float” nurses for more than 60% of the duration of the CVC. In multivariable analysis, risk factors for CVC-associated BSIs were the use of TPN in non-antimicrobial-impregnated CVCs (P= .0001), patient cared for by a float nurse for more than 60% of CVC-days (P= .0019), no antibiotics administered to the patient within 48 hours of insertion (P= .0001), and patient unarousable for 70% or more of the duration of the CVC (P= .0001). Peripherally inserted central catheters (PICCs) were associated with a lower risk for CVC-associated BSI (P= .0001).

Conclusions:

Antimicrobial-impregnated CVCs reduced the risk of CVC-associated BSI by 66% in patients receiving TPN. Limiting the use of float nurses for ICU patients with CVCs and the use of PICCs may also reduce the risk of CVC-associated BSI.

A prospective clinical trial on prevention of catheter contamination using the hub protection cap for needleless injection device

BACKGROUND

Catheter hub contamination has been recognized as a source of catheter-related bloodstream infections. We have investigated the efficacy of a protection cap for a needleless injection device in preventing intraluminal catheter contamination, compared with a conventional 3-way stopcock.

METHODS

Adult patients requiring an intravascular catheter placement for at least 48 hours in an intensive care unit were randomly assigned to receive either the needleless injection device with protection cap (test group, n = 31, number of devices = 151) or with a conventional 3-way stopcock (comparator group, n = 33, number of devices = 179). To evaluate intraluminal contamination, we examined the bacteria isolated in the inline bacterial filters, which were attached downstream of the injection ports.

RESULTS

The incidence of bacterial contamination was significantly different between the groups (test group 2/151 (1.3%) vs comparator group 11/179 (6.2%), P = .04). There was no correlation between the microbial contamination rate and the in situ time of catheter or numbers of injections.

CONCLUSION

The protection cap for needleless injection devices decreased microbial transfer from the injection port to the intraluminal fluid pathway and lowered the risk of catheter-related bloodstream infections.

A Retrospective Study to Determine Whether accessing Frequency Affects the Incidence of Microbial Colonisation in Peripheral Arterial Catheters

Peripheral arterial catheters are used for the continuous monitoring of blood pressure and repeated blood sampling in critically ill patients, but can be a source of catheter-related bloodstream infection. A common assumption is that the more frequently an arterial catheter is accessed, the greater the likelihood of contamination and colonisation to occur. We sought to determine whether the accessing frequency has an influence on the rate of colonisation in a peripheral arterial catheter.

A retrospective, unmatched, nested case control study was conducted in our intensive care unit. The intensive care unit charts of 96 arterial catheters from 83 patients were examined to measure the number of times each respective arterial catheter was accessed. Multivariate Cox proportional hazards regression was used to compare the rate of accessing of arterial catheters and account for varying arterial catheter in situ duration. Arterial catheters which had a high access rate of 8.1 or more times/day (five colonised of 32 patients: hazards ratio 1.69, 95% confidence interval 0.52 to 5.49; P=0.77), or a medium access rate of 6.7 to 8.0 times/day (six colonised of 32 patients: hazards ratio, 1.35, 95% confidence interval, 0.37 to 4.92: P=0.65) were not significantly more colonised when compared to arterial catheters which had a low access rate of 0 to 6.6 times/day (six colonised of 32 patients), adjusted for arterial catheter insertion site and place in hospital where the arterial catheter insertion was performed.

We were unable to demonstrate that the accessing frequency of an arterial catheter was a major predisposing factor for the likelihood of colonisation. Other mechanisms other than hub colonisation should be investigated further.

Catheter-related bloodstream infections in intensive care units: a systematic review with meta-analysis

AIM

This paper is a report of a systematic review and meta-analysis of strategies, other than antimicrobial coated catheters, hypothesized to reduce risk of catheter-related bloodstream infections and catheter colonization in the intensive care unit setting.

BACKGROUND

Catheter-related bloodstream infections occur at a rate of 5 per 1000 catheter days in the intensive care unit setting and cause substantial mortality and excess cost. Reducing risk of catheter-related bloodstream infections among intensive care unit patients will save costs, reduce length of stay, and improve outcomes.

METHODS

A systematic review of studies published between January 1985 and February 2007 was carried out using the keywords 'catheterization - central venous' with combinations of infection*, prevention* and bloodstream*. All included studies were screened by two reviewers, a validated data extraction instrument was used and data collection was completed by two blinded independent reviewers. Risk ratios for catheter-related bloodstream infections and catheter colonization were estimated with 95% confidence intervals for each study. Results from studies of similar interventions were pooled using meta-analyses.

RESULTS

Twenty-three studies were included in the review. The strategies that reduced catheter colonization included insertion of central venous catheters in the subclavian vein rather than other sites, use of alternate skin disinfection solutions before catheter insertion and use of Vitacuff in combination with polymyxin, neomycin and bacitracin ointment. Strategies to reduce catheter-related bloodstream infection included staff education multifaceted infection control programmes and performance feedback.

CONCLUSION

A range of interventions may reduce risks of catheter-related bloodstream infection, in addition to antimicrobial catheters.

Is there evidence for recommending needleless closed catheter access systems in guidelines? A systematic review of randomized controlled trials

A systematic review was conducted to determine whether certain vascular access policies are better than others in terms of prevention of catheter-related infections. Publications were retrieved by a search of Medline, the Cochrane Library and Embase up to May 2005. All randomized trials and systematic reviews/meta-analyses of randomized trials evaluating the effect of vascular access policies (i.e. needleless closed systems, conventional closed systems or conventional open systems) on catheter-related infection in hospitalized patients with intravascular catheters in situ were selected. Two reviewers independently assessed trial quality and extracted data. Data from the original publications were used to calculate the relative risk or the incidence-density relative rate of catheter-related infection. Data for similar outcomes were combined in the analysis where appropriate using a random-effects model. Of the six studies reviewed, one was excluded. Five randomized controlled trials were included in the review. The quality of the trials and the way they were reported were generally unsatisfactory. Four trials compared needleless closed systems with conventional open systems. There was a trend for an advantage of the needleless closed devices in terms of less catheter-associated bloodstream infection, less catheter tip colonization and less hub inlet colonization. There were no possibilities for combining data because of clinical heterogeneity. One trial compared needleless closed systems with conventional closed systems and the evidence was inconclusive. From the point of view of infection prevention, there are no objections to use these new systems. However, there is insufficient evidence at this stage to recommend the needleless closed vascular devices.

A randomized, prospective clinical trial to assess the potential infection risk associated with the PosiFlow needleless connector

The microbial contamination rate of luers of central venous catheters (CVCs) with either PosiFlow needleless connectors or standard caps attached was investigated. The efficacy of 70% (v/v) isopropyl alcohol, 0.5% (w/v) chlorhexidine in gluconate 70% (v/v) isopropyl alcohol and 10% (w/v) aqueous povidone-iodine to disinfect the intravenous connections was also assessed. Seventy-seven patients undergoing cardiac surgery who required a CVC as part of their clinical management were randomly allocated either needleless connectors or standard caps. Patients were also designated to receive chlorhexidine/alcohol, isopropyl alcohol or povidone-iodine for pre-CVC insertion skin preparation and disinfection of the connections. After 72 h in situ the microbial contamination rate of 580 luers, 306 with standard caps and 274 with needleless connectors attached, was determined. The microbial contamination rate of the external compression seals of 274 needleless connectors was also assessed to compare the efficacy of the three disinfectants. The internal surfaces of 55 out of 306 (18%) luers with standard caps were contaminated with micro-organisms, whilst only 18 out of 274 (6.6%) luers with needleless connectors were contaminated (P<0.0001). Of those needleless connectors disinfected with isopropyl alcohol, 69.2% were externally contaminated with micro-organisms compared with 30.8% disinfected with chlorhexidine/alcohol (P<0.0001) and 41.6% with povidone-iodine (P<0.0001). These results suggest that the use of needleless connectors may reduce the microbial contamination rate of CVC luers compared with the standard cap. Furthermore, disinfection of needleless connectors with either chlorhexidine/alcohol or povidone-iodine significantly reduced external microbial contamination. Both these strategies may reduce the risk of catheter-related infections acquired via the intraluminal route.

Prevention and treatment of implanted central venous catheter (CVC) - related sepsis: a report after six years of home parenteral nutrition (HPN)

Catheter-related sepsis is a serious and common complication in patients receiving home parenteral nutrition (HPN). Prevention measures, prevalence of infections, types of agents and implanted central venous catheters (CVC), effectiveness of antibiotic therapy have been evaluated in 221 patients consecutively followed in our unit from January 1995 to December 2000. The clinical diagnosis of catheter-related infection was made using well-defined criteria. Patients were divided into two groups: A and B, receiving instructions with different modalities: standard (A) and detailed (B), respectively. Sixty CVC-related sepsis occurred in 32 (14%) patients. A multivariate analysis showed that the duration of HPN (P<0.001; OR=0.9), type of catheter (P=0.009; OR=0.12) and type of disease (P=0.033; OR=4.92) significantly influence catheter infection. The type of implanted CVC (159 port-a-cath in 153 patients and 71 tunnelled in 68) seems to affect the infection rate, this being lower in tunnelled (P=0.03). Infection rate was lower in B vs A group (P<0.001) with all types of catheters, suggesting the preventive role of very careful training. In particular, the incidence of CVC-related sepsis was 6/1000 days of HPN (i.e. 6/1000 days of catheterization) in Group A and 3/1000 in Group B. Systemic and antibiotic lock therapy was performed with an 83% successful rate. Gram-positive bacteria were the most frequent CVC infection agents, which are usually eradicated by antibiotic therapy lasting 7 days.

Management of intravascular devices to prevent infection

Intravenous therapy is an essential part of clinical care used in a wide variety of healthcare settings. Thus, intravenous catheters have become indispensable to clinical practice. However, catheter-related-bloodstream infections (CR-BSIs) are a major source of morbidity and mortality, especially in hospital patients. Strategies to prevent infection need to change and develop to reflect the advances in technology and delivery of health care. Current guidance recommends a number of strategies to reduce the incidence of CR-BSIs. These include applying the principles of asepsis, the choice of catheter material, the site of insertion and when to replace equipment used. This article reviews the guidelines for current clinical practice.

[Catheter-related infection in intensive care. Physiopathology, diagnosis, treatment and prevention]

PURPOSE

To review the mechanisms, diagnosis, treatment and prophylaxis of catheter-related sepsis in intensive care unit patients.

DATA SOURCES

A Medline research of the English- or French-language reports published between 1966 and 2000 and a manual research of references of relevant papers.

STUDY SELECTION

Experimental, clinical and basic research studies related to catheter-related sepsis.

DATA EXTRACTION

Data in selected articles were reviewed, and relevant clinical information was extracted.

DATA SYNTHESIS

Infection remains the major complication related to catheter insertion. No bacteriological exam or systematic catheter change is required in the absence of infection suspicion. In the intensive care unit, and without septic shock, the surveillance of skin cultures at the catheter insertion site or the time to positivity of hub-blood versus peripheral-blood culture determination may reduce the number of unnecessary removed catheters. Catheter change over a guidewire is not recommended because of the risk of dissemination of infection. When the catheter is removed, a quantitative culture is warranted. The treatment of catheter-related sepsis is based on catheter removal. The use of antibiotics is limited to some organisms or when the infection is complicated. The persistence of fever and positive blood cultures 72 h after catheter removal require to look for dissemination of infection or septic thrombophlebitis, especially if S. aureus or Candida are incriminated. The treatment of infection without catheter removal is not recommended in the intensive care unit because of a high risk of treatment failure. Compliance with catheter care guidelines and continuing quality improvement programs are the two major procedures in reducing catheter infection.

CONCLUSIONS

Improved understanding of the pathophysiology of catheter-related sepsis has led to improved prevention. Compliance with catheter care guidelines and continuing quality improvement programs are majors procedures to reduce the risk of catheter infection.

Evidence-based prevention of catheter infection during parenteral nutrition

Parenteral nutrition is a risk factor for catheter-related bloodstream infection. Here we reviewed strategies for the prevention of catheter-related infections, which always must begin with the cornerstone of prevention: the strict adherence to aseptic techniques. Most research has been interested in coated catheters. From these results, it may be concluded that antibiotics or antiseptic-impregnated catheters, like those with minocycline-rifampicin or chlorhexidine/silver sulfadiazine, significantly reduce catheter-related blood stream infections. Antibiotics or antiseptic-impregnated central venous catheters may even result in cost saving in intensive care units. Antiseptic or antibiotic-lock techniques would also be of interest to prevent catheter-related sepsis in high-risk patients who are receiving parenteral nutrition.