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.

N-acetylcysteine: a novel approach to methaemoglobinaemia in normothermic liver machine perfusion.

Extended duration of normothermic machine perfusion (NMP) provides opportunities to resuscitate suboptimal donor livers. This intervention requires adequate oxygen delivery typically provided by a blood-based perfusion solution. Methaemoglobin (MetHb) results from the oxidation of iron within haemoglobin and represents a serious problem in perfusions lasting > 24 h. We explored the effects of anti-oxidant, N-acetylcysteine (NAC) on the accumulation of methaemoglobin. NMP was performed on nine human donor livers declined for transplantation: three were perfused without NAC (no-NAC group), and six organs perfused with an initial NAC bolus, followed by continuous infusion (NAC group), with hourly methaemoglobin perfusate measurements. In-vitro experiments examined the impact of NAC (3 mg) on red cells (30 ml) in the absence of liver tissue. The no-NAC group sustained perfusions for an average of 96 (range 87-102) h, universally developing methaemoglobinaemia (≥ 2%) observed after an average of 45 h, with subsequent steep rise. The NAC group was perfused for an average of 148 (range 90-184) h. Only 2 livers developed methaemoglobinaemia (peak MetHb of 6%), with an average onset of 116.5 h. Addition of NAC efficiently limits formation and accumulation of methaemoglobin during NMP, and allows the significant extension of perfusion duration.

Antimicrobial activity of a chlorhexidine intravascular catheter site gel dressing.

OBJECTIVES: The antimicrobial efficacy of a chlorhexidine gluconate (CHG) intravascular catheter gel dressing was evaluated against methicillin-resistant Staphylococcus aureus (MRSA) and an extended-spectrum ß-lactamase (ESBL)-producing Escherichia coli. Chlorhexidine deposition on the skin surface and release from the gel were determined. METHODS: The antimicrobial efficacy was evaluated in in vitro studies following microbial inoculation of the dressing and application of the dressing on the inoculated surface of a silicone membrane and donor skin [with and without a catheter segment and/or 10% (v/v) serum] on diffusion cells. Antimicrobial activity was evaluated for up to 7 days. Chlorhexidine skin surface deposition and release were also determined. RESULTS: MRSA and E. coli were not detectable within 5 min following direct inoculation onto the CHG gel dressing. On the silicone membrane, 3 log and 6 log inocula of MRSA were eradicated within 5 min and 1 h, respectively. Time to kill was prolonged in the presence of serum and a catheter segment. Following inoculation of donor skin with 6 log cfu of MRSA, none was detected after 24 h. Chlorhexidine was released from the gel after a lag time of 30 min and increasing amounts were detected on the donor skin surface over the 48 h test period. The CHG gel dressing retained its antimicrobial activity on the artificial skin for 7 days. CONCLUSIONS: The CHG intravascular catheter site gel dressing had detectable antimicrobial activity for up to 7 days, which should suppress bacterial growth on the skin at the catheter insertion site, thereby reducing the risk of infection.

Prevention of central venous catheter-related infection: update.

Central venous catheters (CVCs) are an essential part of modern-day healthcare, but infections associated with these devices continue to cause significant morbidity and mortality. There are many approaches for the prevention of CVC-related infection and these are outlined in national guidelines. The Department of Health Saving Lives campaign has developed a care-bundle for the prevention of CVC-related infections that focuses on the fundamental actions to be undertaken during the catheter insertion process and ongoing care. If the rate of catheter-related infection remains high despite the implementation of these infection prevention strategies, the use of novel antimicrobial technologies and practices may be considered. These include CVCs that contain antimicrobial agents, such as antiseptics or antibiotics, needleless intravenous (IV) access devices coated with silver and/or chlorhexidine, IV dressings incorporating chlorhexidine, and the use of antimicrobial catheter lock solutions, such as antibiotics, chelators or ethanol. This article outlines the different types of CVCs available, the risk of infection associated with their use and established and novel measures for prevention of these infections.

Awareness of Practice and Comparison with Best Evidence in Surgical Site Infection Prevention in Colorectal Surgery.

Background: The use of mechanical bowel preparation and prophylaxis with oral antimicrobial agents can prevent surgical site infection (SSI) in colorectal surgical procedures, but routine adoption of these and other practices by surgeons has been limited. The aim of this study was to determine the actual practice and surgeon beliefs about preventative measures in elective colorectal operations and to compare them with established recommendations. Methods: Web-based survey was sent to colorectal surgeons assessing knowledge, beliefs, and practices regarding the use of preventative measures for SSI. Results: Of 355 surgeons, 33% had no feedback of SSI rate; 60% believed in evidence for normothermia, wound edge protection, and use of alcohol solution, and reported use of these strategies. There was a discrepancy in the assumed evidence and use of hyperoxia, glove replacement after anastomosis, surgical tools replacement, and saline surgical site lavage. Most of respondents believe that oral antibiotic prophylaxis diminishes infection, but is indicated only by one third of them. Few surgeons believe in MBP, but many actually use it. Most surgeons believe that there is a discrepancy between published guidelines and actual clinical practice. As proper means to implement guidelines, checklists, standardized orders, surveillance, feedback of SSI rates, and educational programs are rated most highly by surgeons, but few of these are in place at their institutions. Conclusions: Gaps in the translation of evidence into practice remain in the prevention of SSI in colorectal surgical procedures. Several areas for improvement have been identified. Specific implementation strategies should be addressed in colorectal units.

Progress in the prevention of surgical site infection.

PURPOSE OF REVIEW: The present review summarizes some of the key papers on the prevention of surgical site infections (SSI) published in 2008. RECENT FINDINGS: The National Institute for Health and Clinical Excellence published guidelines on the prevention and management of SSI. These guidelines follow a similar format to those published previously. There are, however, some important differences to previous recommendations and these are outlined in this current article. Other publications have provided additional evidence that suggests certain antiseptic agents are more efficacious than others for surgical hand antisepsis. Staphylococcus aureus decolonization has also been studied and noted to be of benefit for the prevention of SSI. Other research studies have focused on patient homeostasis, including the use of supplemental perioperative oxygen, which has resulted in mixed findings. Finally, the use of surveillance to evaluate the efficacy of 'care bundles' has been reported, which brings together many different approaches for the prevention of SSI. SUMMARY: Several evaluations of pre, peri and postoperative strategies for the prevention of SSI have been published in 2008, some of which have raised some fundamental questions.

A clinical evaluation of two central venous catheter stabilization systems.

BACKGROUND: Central venous catheters (CVCs) are commonly secured with sutures which are associated with microbial colonization and infection. We report a comparison of a suture-free system with standard sutures for securing short-term CVC in an international multicentre, prospective, randomized, non-blinded, observational feasibility study. Consented critical care patients who had a CVC inserted as part of their clinical management were randomized to receive either sutures or the suture-free system to secure their CVC. The main outcome measures were CVC migration (daily measurement of catheter movement) and unplanned catheter removals. RESULTS: The per cent of unplanned CVC removal in the two study groups was 2% (suture group 2 out of 86 patients) and 6% (suture-free group 5 out of 85 patients). Both securement methods were well tolerated in terms of skin irritation. The time and ease of application and removal of either securement systems were not rated significantly different. There was also no significant difference in CVC migration between the two securement systems in exploratory univariate and multivariate analyses. Overall, 42% (36 out of 86) of the CVC secured with sutures and 56% (48 out of 85) of the CVC secured with the suture-free securement system had CVC migration of ≥ 2 mm. CONCLUSIONS: The two securement systems performed similarly in terms of CVC migration and unplanned removal of CVC; however, the feasibility study was not powered to detect statistically significant differences in these two parameters. TRIAL REGISTRATION: ISRCTN, ISRCTN13939744. Registered 9 July 2015, http://www.isrctn.com/ISRCTN13939744 .

Antimicrobial central venous catheters in adults: a systematic review and meta-analysis.

Several antimicrobial central venous catheters (CVCs) are available. We did a meta-analysis to assess their efficacy in reducing microbial colonisation and preventing catheter-related bloodstream infection (CRBSI). An extensive literature search of articles in any language was undertaken. We assessed randomised clinical trials in which available antimicrobial CVCs were compared with either a standard CVC or another antimicrobial CVC. Outcomes assessed were microbial colonisation of CVCs and CRBSI. The first-generation chlorhexidine-silver sulfadiazine (CSS) CVCs reduce colonisation (odds ratio [OR] 0.51 [95% CI 0.42-0.61]) and CRBSI (OR 0.68 [0.47-0.98]), as do the minocycline-rifampicin CVCs (OR 0.39 [0.27-0.55] and OR 0.29 [0.16-0.52], respectively). The minocycline-rifampicin CVCs outperformed the first-generation CSS CVCs in reducing colonisation (OR 0.34 [0.23-0.49]) and CRBSI (OR 0.18 [0.07-0.51]). Many shortcomings in methodological quality limit our interpretation of the study results. However, the available evidence suggests that use of CSS and minocycline-rifampicin CVCs are useful if the incidence of CRBSI is above institutional goals despite full implementation of infection prevention interventions.

An in vitro comparison of standard cleaning to a continuous passive disinfection cap for the decontamination of needle-free connectors.

Background: The optimal decontamination method for needle-free connectors is still unresolved. The objective of this study was to determine if a continuous passive disinfection cap is as effective as standard cleaning for the microbial decontamination of injection ports of two types of needle-free connectors. Methods: The injection ports of needle-free connectors were inoculated with Staphylococcus aureus and allowed to dry. Disinfection caps containing 70% (v/v) isopropyl alcohol (IPA) were attached to the connectors for one, three or 7 days and were compared with needle-free connectors cleaned with 2% (w/v) chlorhexidine gluconate (CHG) in 70% (v/v) IPA. The number of S. aureus remaining on the injection ports was evaluated. Median log10 reductions and 95% confidence interval (CI) were calculated and data analyzed using the Mann-Whitney test. Results: The application of the disinfection cap resulted in a significantly higher reduction in S. aureus than the 2% (w/v) CHG in 70% (v/v) IPA wipe, achieving a > 5 Log10 reduction in CFU at each time point. Conclusions: The disinfection caps resulted in a significantly higher reduction in S.aureus on the injection ports when compared to the use of a 2% (w/v) CHG in 70% (v/v) IPA wipe. This offers an explanation for the lower rates of central-line associated bloodstream infection (CLABSI) associated with the use of disinfection caps reported in clinical studies.

A survey to identify the breach between evidence and practice in the prevention of surgical infection: Time to take action.

BACKGROUND: The knowledge of the grade of implementation of preventative measures for surgical site infection (SSI) is crucial prior to planning dissemination strategies. METHODS: Online survey among the members of the Spanish Association of Surgeons (AEC) to know the actual application of measures, and to compare them with new recommendations issued by international organizations. RESULTS: Most of the 835 responding surgeons work in National Health Service Hospitals (91.3%). Surgeons of all super-specialties answered. 90.4% of responders recommend a preoperative shower, with normal soap or chlorhexidine. 60% recommend hair removal, preferably clipping, although 30% still recommend shaving. Povidone-iodine in aqueous solution or chlorhexidine in alcohol are used for skin preparation. Only 51.9% of surgeons allow solution to air drying before applying surgical drapes. In 83.2% of cases surgeons operate with a single pair of gloves. Perioperative normothermia and hyperoxia were used in 92% and 27.9% of cases, respectively. At the end of the procedure, peritoneal and wound lavage are used, in most cases with saline. Antimicrobial impregnated sutures are rarely used (85.7%) by surgeons, and 32% occasionally use negative pressure therapy on the closed wound. CONCLUSIONS: There is great variability in the level of awareness and application of the main measures of SSI prevention among Spanish surgeons. Several areas for improvement have been detected, as core prevention measures are not in common use, and discontinued practices are continued to be used. These practices should be addressed by the AEC by drafting specific recommendations for the prevention of SSI in Spanish hospitals.

Evaluation of routine microbiological techniques for establishing the diagnosis of catheter-related bloodstream infection caused by coagulase-negative staphylococci.

Microbiological diagnosis of catheter-related bloodstream infection (CR-BSI) is often based on isolation of indistinguishable micro-organisms from an explanted catheter tip and blood culture, confirmed by antibiograms. Whether phenotypic identification of coagulase-negative staphylococci (CoNS) allows an accurate diagnosis of CR-BSI to be established was evaluated. Eight patients with a diagnosis of CR-BSI had CoNS isolated from pure blood cultures and explanted catheter tips which were considered as indistinguishable strains by routine microbiological methods. For each patient, an additional three colonies of CoNS isolated from the blood and five from the catheter tip were subcultured and further characterized by antibiogram profiles, analytical profile index (API) biotyping and PFGE. PFGE distinguished more strains of CoNS compared to API biotyping or antibiograms (17, 10 and 11, respectively). By PFGE, indistinguishable micro-organisms were only isolated from pure blood and catheter tip cultures in four out of eight (50%) patients thus supporting the diagnosis of CR-BSI. In another patient, indistinguishable micro-organisms were identified in both cultures; however, other strains of CoNS were also present. The remaining three patients had multiple strains of CoNS, none of which were indistinguishable in the tip and blood cultures, thus questioning the diagnosis of CR-BSI. Phenotypic characterization of CoNS lacked discriminatory power. Current routine methods of characterizing a limited number of pooled colonies may generate misleading results as multiple strains may be present in the cultures. Multiple colonies should be studied using a rapid genotypic characterization method to confirm or refute the diagnosis of CR-BSI.

The usability and acceptability of a needleless connector system.

Needleless connectors were introduced into clinical practice to reduce the rate of needlestick injuries to healthcare workers (HCWs). There have, however, been limited reports of user acceptability of these devices. The usability and acceptability of the Clearlink needleless connector (Baxter Healthcare, UK) was therefore completed by HCWs at University Hospital Birmingham NHS Foundation Trust following a 12-month clinical evaluation. Seventy percent (28/40) of HCWs reported that they would prefer to use Clearlink needleless connectors rather than conventional luers caps, 15% (6/40) would use either, and only 15% (6/40) preferred to use luer caps. In total, 85% of HCWs reported that Clearlink was acceptable to use in the clinical situation. The results demonstrate that comprehensive training and technical support both before and after new device implementation were essential to ensure a smooth transition.

Infection risks associated with needleless intravenous access devices.

Needleless intravenous (i.v.) access devices were initially introduced into clinical practice to reduce the rate of i.v. catheter-related needlestick injuries. Their efficacy for this purpose has been confirmed in subsequent reports. However, since their introduction approximately 15 years ago there have been conflicting reports about the risk of i.v. catheter-related bloodstream infection. This article reviews the risk of catheter-related bloodstream infection associated with needleless i.v. access devices and outlines the types of needleless i.v. access devices available.

Clinical evaluation of a chlorhexidine intravascular catheter gel dressing on short-term central venous catheters.

BACKGROUND: A major source of microbial colonization of short-term central venous catheters (CVC) is the patients' endogenous skin microorganisms located at the CVC insertion site. The aim of this study was to determine if a transparent film dressing incorporating a 2% (weight/weight) chlorhexidine gluconate (CHG) gel decreases CVC and insertion site microbial colonization compared with a nonantimicrobial dressing in adult patients in critical care. METHODS: On CVC removal, samples for microbiological investigation were taken from both the skin surrounding the CVC insertion site and also from sutures securing the CVC. The sutures and intradermal and tip sections of the CVC were also collected for microbiological investigation. Microorganisms recovered from the samples were subsequently tested for susceptibility to CHG. RESULTS: There was a significant reduction in the number of microorganisms recovered from the CVC insertion site, suture site, sutures, and catheter surface in the CHG dressing group (n = 136) compared with the nonantimicrobial dressing group (n = 137). There was no significant difference in susceptibility to CHG between the microorganisms isolated from the CHG and standard dressing study patients. CONCLUSION: A film dressing incorporating a CHG gel pad significantly reduced the number of microorganisms at the CVC insertion and suture sites with concomitant reduced catheter colonization.

Impact of catheter antimicrobial coating on species-specific risk of catheter colonization: a meta-analysis.

BACKGROUND: Antimicrobial catheters have been utilized to reduce risk of catheter colonization and infection. We aimed to determine if there is a greater than expected risk of microorganism-specific colonization associated with the use of antimicrobial central venous catheters (CVCs). METHODS: We performed a meta-analysis of 21 randomized, controlled trials comparing the incidence of specific bacterial and fungal species colonizing antimicrobial CVCs and standard CVCs in hospitalized patients. RESULTS: The proportion of all colonized minocycline-rifampin CVCs found to harbor Candida species was greater than the proportion of all colonized standard CVCs found to have Candida. In comparison, the proportion of colonized chlorhexidine-silver sulfadiazine CVCs specifically colonized with Acinetobacter species or diphtheroids was less than the proportion of similarly colonized standard CVCs. No such differences were found with CVCs colonized with staphylococci. CONCLUSION: Commercially-available antimicrobial CVCs in clinical use may become colonized with distinct microbial flora probably related to their antimicrobial spectrum of activity. Some of these antimicrobial CVCs may therefore have limited additional benefit or more obvious advantages compared to standard CVCs for specific microbial pathogens. The choice of an antimicrobial CVC may be influenced by a number of clinical factors, including a previous history of colonization or infection with Acinetobacter, diphtheroids, or Candida species.

A comparative study to evaluate surface microbial contamination associated with copper-containing and stainless steel pens used by nurses in the critical care unit.

A clinical study was undertaken to compare the surface microbial contamination associated with pens constructed of either a copper alloy or stainless steel used by nurses on intensive care units. A significantly lower level of microbial contamination was found on the copper alloy pens.

Efficacy of adding 2% (w/v) chlorhexidine gluconate to 70% (v/v) isopropyl alcohol for skin disinfection prior to peripheral venous cannulation.

We undertook a clinical trial to compare the efficacy of 2% (w/v) chlorhexidine gluconate in 70% (v/v) isopropyl alcohol with the efficacy of 70% (v/v) isopropyl alcohol alone for skin disinfection to prevent peripheral venous catheter colonization and contamination. We found that the addition of 2% chlorhexidine gluconate reduced the number of peripheral venous catheters that were colonized or contaminated.