A prospective, randomized trial of rifampicin-minocycline-coated and silver-platinum-carbon-impregnated central venous catheters*

Hypochlorous Acid-Generating Electrochemical Catheter Prototype for Prevention of Intraluminal Infection

Central line-associated bloodstream infection (CLABSI) contributes to mortality and cost. While aseptic dressings and antibiotic-impregnated catheters prevent some extraluminal infections, intraluminal infections remain a source of CLABSIs. In this proof-of-concept study, an electrochemical intravascular catheter (e-catheter) prototype capable of electrochemically generating hypochlorous acid intraluminally using platinum electrodes polarized at a constant potential of 1.5 electrode potential relative to saturated silver/silver chloride reference electrode measured in volts (V_Ag/AgCl) was developed. After 24 h of prepolarization at 1.5 V_Ag/AgCl, their activity was tested against clinical isolates of Staphylococcus aureus, Staphylococcus epidermidis, Enterococcus faecium, and Escherichia coli derived from catheter-related infections. e-catheters generated a mean HOCl concentration of 15.86 ± 4.03 μM and had a mean pH of 6.14 ± 0.79. E-catheters prevented infections of all four species, with an average reduction of 8.41 ± 0.61 log₁₀ CFU/ml at 48 h compared to controls. Polarized e-catheters which generate low amounts of HOCl continuously should be further developed to prevent intraluminal infection. IMPORTANCE Catheter-related infections constitute an economic and mortality burden in health care. Several options are available to reduce the risk of infection, but only a few focus on preventing intraluminal infection, which occurs in long-term catheters, most often used for dialysis, prolonged treatment, or chemotherapy. A prototype of a catheter called an "e-catheter" composed of three electrodes, capable of producing hypochlorous acid (HOCl) electrochemically in its lumen, was developed. When polarized at 1.5 V, chloride ions in the solution are oxidized to continuously produce low amounts of HOCl, which exhibits antibacterial activity in the lumen of the catheter. Here, this prototype was shown to be able to generate HOCl as well as prevent infection in a preliminary in vitro catheter model. This approach is a potential strategy for catheter infection prevention.

Antimicrobial-impregnated central venous catheters for preventing neonatal bloodstream infection: the PREVAIL RCT

BACKGROUND

Clinical trials show that antimicrobial-impregnated central venous catheters reduce catheter-related bloodstream infection in adults and children receiving intensive care, but there is insufficient evidence for use in newborn babies.

OBJECTIVES

The objectives were (1) to determine clinical effectiveness by conducting a randomised controlled trial comparing antimicrobial-impregnated peripherally inserted central venous catheters with standard peripherally inserted central venous catheters for reducing bloodstream or cerebrospinal fluid infections (referred to as bloodstream infections); (2) to conduct an economic evaluation of the costs, cost-effectiveness and value of conducting additional research; and (3) to conduct a generalisability analysis of trial findings to neonatal care in the NHS.

DESIGN

Three separate studies were undertaken, each addressing one of the three objectives. (1) This was a multicentre, open-label, pragmatic randomised controlled trial; (2) an analysis was undertaken of hospital care costs, lifetime cost-effectiveness and value of information from an NHS perspective; and (3) this was a retrospective cohort study of bloodstream infection rates in neonatal units in England.

SETTING

The randomised controlled trial was conducted in 18 neonatal intensive care units in England.

PARTICIPANTS

Participants were babies who required a peripherally inserted central venous catheter (of 1 French gauge in size).

INTERVENTIONS

The interventions were an antimicrobial-impregnated peripherally inserted central venous catheter (coated with rifampicin-miconazole) or a standard peripherally inserted central venous catheter, allocated randomly (1 : 1) using web randomisation.

MAIN OUTCOME MEASURE

Study 1 - time to first bloodstream infection, sampled between 24 hours after randomisation and 48 hours after peripherally inserted central venous catheter removal. Study 2 - cost-effectiveness of the antimicrobial-impregnated peripherally inserted central venous catheter compared with the standard peripherally inserted central venous catheters. Study 3 - risk-adjusted bloodstream rates in the trial compared with those in neonatal units in England. For study 3, the data used were as follows: (1) case report forms and linked death registrations; (2) case report forms and linked death registrations linked to administrative health records with 6-month follow-up; and (3) neonatal health records linked to infection surveillance data.

RESULTS

Study 1, clinical effectiveness - 861 babies were randomised (antimicrobial-impregnated peripherally inserted central venous catheter, n = 430; standard peripherally inserted central venous catheter, n = 431). Bloodstream infections occurred in 46 babies (10.7%) randomised to antimicrobial-impregnated peripherally inserted central venous catheters and in 44 (10.2%) babies randomised to standard peripherally inserted central venous catheters. No difference in time to bloodstream infection was detected (hazard ratio 1.11, 95% confidence interval 0.73 to 1.67; p = 0.63). Secondary outcomes of rifampicin resistance in positive blood/cerebrospinal fluid cultures, mortality, clinical outcomes at neonatal unit discharge and time to peripherally inserted central venous catheter removal were similar in both groups. Rifampicin resistance in positive peripherally inserted central venous catheter tip cultures was higher in the antimicrobial-impregnated peripherally inserted central venous catheter group (relative risk 3.51, 95% confidence interval 1.16 to 10.57; p = 0.02) than in the standard peripherally inserted central venous catheter group. Adverse events were similar in both groups. Study 2, economic evaluation - the mean cost of babies' hospital care was £83,473. Antimicrobial-impregnated peripherally inserted central venous catheters were not cost-effective. Given the increased price, compared with standard peripherally inserted central venous catheters, the minimum reduction in risk of bloodstream infection for antimicrobial-impregnated peripherally inserted central venous catheters to be cost-effective was 3% and 15% for babies born at 23-27 and 28-32 weeks' gestation, respectively. Study 3, generalisability analysis - risk-adjusted bloodstream infection rates per 1000 peripherally inserted central venous catheter days were similar among babies in the trial and in all neonatal units. Of all bloodstream infections in babies receiving intensive or high-dependency care in neonatal units, 46% occurred during peripherally inserted central venous catheter days.

LIMITATIONS

The trial was open label as antimicrobial-impregnated and standard peripherally inserted central venous catheters are different colours. There was insufficient power to determine differences in rifampicin resistance.

CONCLUSIONS

No evidence of benefit or harm was found of peripherally inserted central venous catheters impregnated with rifampicin-miconazole during neonatal care. Interventions with small effects on bloodstream infections could be cost-effective over a child's life course. Findings were generalisable to neonatal units in England. Future research should focus on other types of antimicrobial impregnation of peripherally inserted central venous catheters and alternative approaches for preventing bloodstream infections in neonatal care.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN81931394.

FUNDING

This project was funded by the National Institute for Health Research Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 24, No. 57. See the NIHR Journals Library website for further project information.

The Impact of Engineered Silver Nanomaterials on the Immune System

Over the last decades there has been a tremendous volume of research efforts focused on engineering silver-based (nano)materials. The interest in silver has been mostly driven by the element capacity to kill pathogenic bacteria. In this context, the main area of application has been medical devices that are at significant risk of becoming colonized by bacteria and subsequently infected. However, silver nanomaterials have been incorporated in a number of other commercial products which may or may not benefit from antibacterial protection. The rapid expansion of such products raises important questions about a possible adverse influence on human health. This review focuses on examining currently available literature and summarizing the current state of knowledge of the impact of silver (nano)materials on the immune system. The review also looks at various surface modification strategies used to generate silver-based nanomaterials and the immunomodulatory potential of these materials. It also highlights the immune response triggered by various silver-coated implantable devices and provides guidance and perspective towards engineering silver nanomaterials for modulating immunological consequences.

Elucidating the Structure-Function Relationship of Solvent and Cross-Linker on Affinity-Based Release from Cyclodextrin Hydrogels

Minocycline (MNC) is a tetracycline antibiotic capable of associating with cyclodextrin (CD), and it is a frontline drug for many instances of implant infection. Due to its broad-spectrum activity and long half-life, MNC represents an ideal drug for localized delivery; however, classic polymer formulations, particularly hydrogels, result in biphasic release less suitable for sustained anti-microbial action. A polymer delivery system capable of sustained, steady drug delivery rates poses an attractive target to maximize the antimicrobial activity of MNC. Here, we formed insoluble hydrogels of polymerized CD (pCD) with a range of crosslinking densities, and then assessed loading, release, and antimicrobial activity of MNC. MNC loads between 5-12 wt % and releases from pCD hydrogels for >14 days. pCD loaded with MNC shows extended antimicrobial activity against S. aureus for >40 days and E. coli for >70 days. We evaluated a range of water/ethanol blends to test our hypothesis that solvent polarity will impact drug-CD association as a function of hydrogel swelling and crosslinking. Increased polymer crosslinking and decreased solvent polarity both reduced MNC loading, but solvent polarity showed a dramatic reduction independent of hydrogel swelling. Due to its high solubility and excellent delivery profile, MNC represents a unique drug to probe the structure-function relationship between drug, affinity group, and polymer crosslinking ratio.

Minocycline, focus on mechanisms of resistance, antibacterial activity, and clinical effectiveness: Back to the future

OBJECTIVES

The increasing crisis regarding multidrug-resistant (MDR) and extensively drug-resistant microorganisms leads to appealing therapeutic options.

METHODS

During the last 30 years, minocycline, a wide-spectrum antimicrobial agent, has been effective against MDR Gram-positive and Gram-negative bacterial infections. As with other tetracyclines, the mechanism of action of minocycline involves attaching to the bacterial 30S ribosomal subunit and preventing protein synthesis.

RESULTS

This antimicrobial agent has been approved for the treatment of acne vulgaris, some sexually transmitted diseases and rheumatoid arthritis. Although many reports have been published, there remains limited information regarding the prevalence, mechanism of resistance and clinical effectiveness of minocycline.

CONCLUSION

Thus, we summarize here the currently available data concerning pharmacokinetics and pharmacodynamics, mechanism of action and resistance, antibacterial activity and clinical effectiveness of minocycline.

Validity of surrogate endpoints assessing central venous catheter-related infection: evidence from individual- and study-level analyses

OBJECTIVES

The prevention of catheter-related bloodstream infection (CRBSI) has been an area of intense research, but the heterogeneity of endpoints used to define catheter infection makes the interpretation of randomized controlled trials (RCTs) problematic. The aim of this study was to determine the validity of different endpoints for central venous catheter infections.

DATA SOURCES

(a) Individual-catheter data were collected from 9428 catheters from four large RCTs; (b) study-level data from 70 RCTs were identified with a systematic search. Eligible studies were RCTs published between January 1987 and October 2018 investigating various interventions to reduce infections from short-term central venous catheters or short-term dialysis catheters. For each RCT the prevalence rates of CRBSI, quantitative catheter tip colonization, catheter-associated infection (CAI) and central line-associated bloodstream infection (CLABSI) were extracted for each randomized study arm.

METHODS

CRBSI was used as the gold-standard endpoint, for which colonization, CAI and CLABSI were evaluated as surrogate endpoints. Surrogate validity was assessed as (1) the individual partial coefficient of determination (individual-pR²) using individual catheter data; (2) the coefficient of determination (study-R²) from mixed-effect models regressing the therapeutic effect size of the surrogates on the effect size of CRBSI, using study-level data.

RESULTS

Colonization showed poor agreement with CRBSI at the individual-patient level (pR² = 0.33 95% CI 0.28-0.38) and poor capture at the study level (R² = 0.42, 95% CI 0.21-0.58). CAI showed good agreement with CRBSI at the individual-patient level (pR² = 0.80, 95% CI 0.76-0.83) and moderate capture at the study level (R² = 0.71, 95% CI 0.51-0.85). CLABSI showed poor agreement with CRBSI at the individual patient level (pR² = 0.34, 95% CI 0.23-0.46) and poor capture at the study level (R² = 0.28, 95% CI 0.07-0.76).

CONCLUSIONS

CAI is a moderate to good surrogate endpoint for CRBSI. Colonization and CLABSI do not reliably reflect treatment effects on CRBSI and are consequently more suitable for surveillance than for clinical effectiveness research.

Complication and Failures of Central Vascular Access Device in Adult Critical Care Settings

OBJECTIVES

To examine the proportion and rate of central venous access device failure and complications across central venous access device types in adult intensive care.

DATA SOURCES

A systematic search was undertaken in the electronic databases Cochrane Central Register of Controlled Trials, Embase, U.S. National Library of Medicine National Institutes of Health, and Cumulative Index to Nursing and Allied Health in September 2017.

STUDY SELECTION

Included studies were of observational (prospective and retrospective) or interventional design and reported central venous access device failure and complications in adult ICU settings. Studies were excluded if they were published prior to November 2006 or not reported in English. Two reviewers independently screened articles, assessed eligibility, extracted data, and assessed risk of bias.

DATA EXTRACTION

Data were extracted on the primary outcome, central venous access device failure, and secondary outcomes: central venous access device complications (central line-associated bloodstream infection, catheter-related bloodstream infection, catheter-related thrombosis, occlusion, catheter removal due to suspected infection, dislodgement, breakage, and local infection). Patient and device data and study details to assess the study quality were also extracted.

DATA SYNTHESIS

A total of 63 studies involving 50,000 central venous access devices (396,951 catheter days) were included. Central venous access device failure was 5% (95% CI, 3-6%), with the highest rates and proportion of failure in hemodialysis catheters. Overall central line-associated bloodstream infection rate was 4.59 per 1,000 catheter days (95% CI, 2.31-6.86), with the highest rate in nontunneled central venous access devices. Removal of central venous access device due to suspected infection was high (17%; 20.4 per 1,000 catheter days; 95% CI, 15.7-25.2).

CONCLUSIONS

Central venous access device complications and device failure is a prevalent and significant problem in the adult ICU, leading to substantial patient harm and increased healthcare costs. The high proportion of central venous access devices removed due to suspicion of infection, despite low overall central line-associated bloodstream infection and catheter-related bloodstream infection rates, indicates a need for robust practice guidelines to inform decision-making surrounding removal of central venous access devices suspected of infection.

Antimicrobial-impregnated central venous catheters for prevention of neonatal bloodstream infection (PREVAIL): an open-label, parallel-group, pragmatic, randomised controlled trial

BACKGROUND

Bloodstream infection is associated with high mortality and serious morbidity in preterm babies. Evidence from clinical trials shows that antimicrobial-impregnated central venous catheters (CVCs) reduce catheter-related bloodstream infection in adults and children receiving intensive care, but there is a paucity of similar evidence for babies receiving neonatal intensive care.

METHODS

This open-label, parallel-group, pragmatic, randomised controlled trial was done in 18 neonatal intensive care units in England. Newborn babies who needed a peripherally inserted CVC (PICC) were allocated randomly (1:1) to receive either a PICC impregnated with miconazole and rifampicin or a standard (non-antimicrobial-impregnated) PICC. Random allocation was done with a web-based program, which was centrally controlled to ensure allocation concealment. Randomisation sequences were computer-generated in random blocks of two and four, and stratified by site. Masking of clinicians to PICC allocation was impractical because rifampicin caused brown staining of the antimicrobial-impregnated PICC. However, participant inclusion in analyses and occurrence of outcome events were determined following an analysis plan that was specified before individuals saw the unblinded data. The primary outcome was the time from random allocation to first microbiologically confirmed bloodstream or cerebrospinal fluid (CSF) infection between 24 h after randomisation and 48 h after PICC removal or death. We analysed outcome data according to the intention-to-treat principle. We excluded babies for whom a PICC was not inserted from safety analyses, as these analyses were done with groups defined by the PICC used. This trial is registered with ISRCTN, number 81931394.

FINDINGS

Between Aug 12, 2015, and Jan 11, 2017, we randomly assigned 861 babies (754 [88%] born before 32 weeks of gestation) to receive an antimicrobial-impregnated PICC (430 babies) or standard PICC (431 babies). The median time to PICC removal was 8·20 days (IQR 4·77-12·13) in the antimicrobial-impregnated PICC group versus 7·86 days (5·00-12·53) days in the standard PICC group (hazard ratio [HR] 1·03, 95% CI 0·89-1·18, p=0·73), with 46 (11%) of 430 babies versus 44 (10%) of 431 babies having a microbiologically confirmed bloodstream or CSF infection. The time from random allocation to first bloodstream or CSF infection was similar between the two groups (HR 1·11, 95% CI 0·73-1·67, p=0·63). Secondary outcomes relating to infection, rifampicin resistance in positive blood or CSF cultures, mortality, clinical outcomes at neonatal unit discharge, and time to PICC removal were similar between the two groups, although rifampicin resistance in positive cultures of PICC tips was higher in the antimicrobial-impregnated PICC group (relative risk 3·51, 95% CI 1·16-10·57, p=0·018). 60 adverse events were reported from 49 (13%) patients in the antimicrobial-impregnated PICC group and 50 events from 45 (10%) babies in the standard PICC group.

INTERPRETATION

We found no evidence of benefit or harm associated with miconazole and rifampicin-impregnated PICCs compared with standard PICCs for newborn babies. Future research should focus on other types of antimicrobial impregnation of PICCs and alternative approaches for preventing infection.

FUNDING

UK National Institute for Health Research Health Technology Assessment programme.

Assessment of the Potential for Inducing Resistance in Multidrug-Resistant Organisms from Exposure to Minocycline, Rifampin, and Chlorhexidine Used To Treat Intravascular Devices

To assess the potential for the induction of antimicrobial resistance following repeated subinhibitory exposures to the combination minocycline (MIN), rifampin (RIF), and chlorhexidine (CHX), a total of 29 clinical microbial pathogenic isolates were repeatedly exposed to subinhibitory concentrations of MIN, RIF, and CHX for 20 passages. MICs of the MIN, RIF, and CHX combination were assessed at each passage to evaluate the potential for resistance to have been induced. The combination of MIN, RIF, and CHX showed significant antimicrobial efficacy and synergy against organisms resistant to all 3 individual components (MIC of ≥16 μg/ml for MIN or MIC of ≥4 μg/ml for RIF or CHX). Among the organisms originally resistant to 2 or more individual components and the organisms originally susceptible to 2 or more individual components, there was no evidence that organisms became resistant following 20 repeated subinhibitory exposure cycles to the triple combination. The risk of resistance developing to the triple combination is extremely low because microbes are inhibited or killed before resistance can simultaneously emerge to all three agents. Surveillance studies monitoring the development of resistance should be conducted in a clinical setting.

Effectiveness of antimicrobial-coated central venous catheters for preventing catheter-related blood-stream infections with the implementation of bundles: a systematic review and network meta-analysis

Background

Catheter-related blood-stream infections (CRBSIs) are the most common complication when using central venous catheters (CVCs). Whether coating CVCs under bundles could further reduce the incidence of CRBSIs is unclear. We aimed to assess the effectiveness of implementing the use of bundles with antimicrobial-coated CVCs for preventing catheter-related blood-stream infections.

Methods

In this systematic review and network meta-analyses, we searched the Cochrane Central Register of Controlled Trials (CENTRAL) in the Cochrane Library in addition to the EMBASE, MEDLINE, CINAHL, and Web of Science databases for studies published before July 2017. The primary outcome was the rate of CRBSIs per 1000 catheter-days, and the secondary outcome was the incidence of catheter colonization.

Results

Twenty-three studies revealed significant differences in the rate of CRBSIs per 1000 catheter-days between antimicrobial-impregnated and standard CVCs (RR 0.70, 95% CI 0.53–0.91, p = 0.008). Thirty-three trials were included containing 10,464 patients who received one of four types of CVCs. Compared with a standard catheter, chlorhexidine/silver sulfadiazine- and antibiotic-coated catheters were associated with lower numbers of CRBSIs per 1000 catheter-days (ORs and 95% CrIs: 0.64 (0.40–0.955) and 0.53 (0.25–0.95), respectively) and a lower incidence of catheter colonization (ORs and 95% CrIs: 0.44 (0.34–0.56) and 0.30 (0.20–0.46), respectively).

Conclusions

Outcomes are superior for catheters impregnated with chlorhexidine/silver sulfadiazine or other antibiotics than for standard catheters in preventing CRBSIs and catheter colonization under bundles. Compared with silver ion-impregnated CVCs, chlorhexidine/silver sulfadiazine antiseptic catheters resulted in fewer cases of microbial colonization of the catheter but did not reduce CRBSIs.

Electronic supplementary material

The online version of this article (10.1186/s13613-018-0416-4) contains supplementary material, which is available to authorized users.

Comparative Efficacy of Antimicrobial Central Venous Catheters in Reducing Catheter-Related Bloodstream Infections in Adults: Abridged Cochrane Systematic Review and Network Meta-Analysis

Background

The efficacy of antimicrobial central venous catheters (CVCs) remains questionable. In this network meta-analysis, we aimed to assess the comparative efficacy of antimicrobial CVC impregnations in reducing catheter-related infections in adults.

Methods

We searched 4 electronic databases (Medline, the Cochrane Central Register of Controlled Trials, Embase, CINAHL) and internet sources for randomized controlled trials, ongoing clinical trials, and unpublished studies up to August 2016. Studies that assessed CVCs with antimicrobial impregnation with nonimpregnated catheters or catheters with another impregnation were included. Primary outcomes were clinically diagnosed sepsis, catheter-related bloodstream infection (CRBSI), and all-cause mortality. We performed a network meta-analysis to estimate risk ratio (RR) with 95% confidence interval (CI).

Results

Sixty studies with 17255 catheters were included. The effects of 14 impregnations were investigated. Both CRBSI and catheter colonization were the most commonly evaluated outcomes. Silver-impregnated CVCs significantly reduced clinically diagnosed sepsis compared with silver-impregnated cuffs (RR, 0.54 [95% CI, .29-.99]). When compared to no impregnation, significant CRBSI reduction was associated with minocycline-rifampicin (RR, 0.29 [95% CI, .16-.52]) and silver (RR, 0.57 [95% CI, .38-.86]) impregnations. No impregnations significantly reduced all-cause mortality. For catheter colonization, significant decreases were shown by miconazole-rifampicin (RR, 0.14 [95% CI, .05-.36]), 5-fluorouracil (RR, 0.34 [95% CI, .14-.82]), and chlorhexidine-silver sulfadiazine (RR, 0.60 [95% CI, .50-.72]) impregnations compared with no impregnation. None of the studies evaluated antibiotic/antiseptic resistance as the outcome.

Conclusions

Current evidence suggests that the minocycline-rifampicin-impregnated CVC appears to be the most effective in preventing CRBSI. However, its overall benefits in reducing clinical sepsis and mortality remain uncertain. Surveillance for antibiotic resistance attributed to the routine use of antimicrobial-impregnated CVCs should be emphasized in future trials.

Anti-Candida activity of antimicrobial impregnated central venous catheters

Background

Whenever the rate of central line-associated bloodstream infections (CLABSIs) remains high even after the implementation of preventive strategies, the use of chlorhexidine/silver sulfadiazine (CSS) or minocycline/rifampin (MR)-impregnated central venous catheters (CVCs) is currently recommended. Nevertheless, the efficacy of such CVCs against Candida albicans and other emerging non-albicans spp. has been insufficiently studied. This study aims to compare the activity of CSS and MR-impregnated CVCs against the yeasts most frequently isolated from CLABSIs.

Methods

For biofilm formation assays, type strains and clinical isolates of C. albicans, C. glabrata and C. parapsilosis sensu stricto were used. Segments of standard polyurethane, MR and second-generation CSS-CVCs were tested. The biofilm metabolic activity was measured by a semi-quantitative XTT reduction assay.

Results

CSS catheter segments significantly reduced the biofilm metabolic activity by all tested Candida spp., with inhibition ranging from 60% to 100%. The MR catheter segments promoted C. albicans and C. parapsilosis biofilm formation and exhibited an inconspicuous effect against C. glabrata.

Conclusions

Among the recommended antimicrobial CVCs, CSS-CVCs proved to be superior in the inhibition of biofilm formation by the most frequent yeasts causing CLABSIs. Data from this in vitro study may suggest that patients at high risk for invasive candidosis could benefit from the use of CSS-CVCs.

Sodium Mercaptoethane Sulfonate Reduces Collagenolytic Degradation and Synergistically Enhances Antimicrobial Durability in an Antibiotic-Loaded Biopolymer Film for Prevention of Surgical-Site Infections

Implant-associated surgical-site infections can have significant clinical consequences. Previously we reported a method for prophylactically disinfecting implant surfaces in surgical pockets, where an antibiotic solution containing minocycline (M) and rifampin (R) was applied as a solid film in a crosslinked biopolymer matrix that partially liquefied in situ to provide extended prophylaxis. Here we studied the effect of adding sodium 2-mercaptoethane sulfonate (MeSNA) on durability of prophylaxis in an in vitro model of implant-associated surgical-site infection. Adding MeSNA to the M/R biopolymer, antimicrobial film extended the duration for which biofilm formation by multidrug-resistant Pseudomonas aeruginosa (MDR-PA) was prevented on silicone surfaces in the model. M/R films with and without MeSNA were effective in preventing colonization by methicillin-resistant Staphylococcus aureus. Independent experiments revealed that MeSNA directly inhibited proteolytic digestion of the biopolymer film and synergistically enhanced antimicrobial potency of M/R against MDR-PA. Incubation of the MeSNA containing films with L929 fibroblasts revealed no impairment of cellular metabolic activity or viability.

Randomized controlled trials in central vascular access devices: A scoping review

BACKGROUND

Randomized controlled trials evaluate the effectiveness of interventions for central venous access devices, however, high complication rates remain. Scoping reviews map the available evidence and demonstrate evidence deficiencies to focus ongoing research priorities.

METHOD

A scoping review (January 2006-December 2015) of randomized controlled trials evaluating the effectiveness of interventions to improve central venous access device outcomes; including peripherally inserted central catheters, non-tunneled, tunneled and totally implanted venous access catheters. MeSH terms were used to undertake a systematic search with data extracted by two independent researchers, using a standardized data extraction form.

RESULTS

In total, 178 trials were included (78 non-tunneled [44%]; 40 peripherally inserted central catheters [22%]; 20 totally implanted [11%]; 12 tunneled [6%]; 6 non-specified [3%]; and 22 combined device trials [12%]). There were 119 trials (68%) involving adult participants only, with 18 (9%) pediatric and 20 (11%) neonatal trials. Insertion-related themes existed in 38% of trials (67 RCTs), 35 RCTs (20%) related to post-insertion patency, with fewer trials on infection prevention (15 RCTs, 8%), education (14RCTs, 8%), and dressing and securement (12 RCTs, 7%). There were 46 different study outcomes reported, with the most common being infection outcomes (161 outcomes; 37%), with divergent definitions used for catheter-related bloodstream and other infections.

CONCLUSION

More high quality randomized trials across central venous access device management are necessary, especially in dressing and securement and patency. These can be encouraged by having more studies with multidisciplinary team involvement and consumer engagement. Additionally, there were extensive gaps within population sub-groups, particularly in tunneled devices, and in pediatrics and neonates. Finally, outcome definitions need to be unified for results to be meaningful and comparable across studies.

Drug eluting antimicrobial vascular catheters: Progress and promise

Vascular catheters are critical tools in modern healthcare yet present substantial risks of serious bloodstream infections that exact significant health and economic burdens. Drug-eluting antimicrobial vascular catheters have become important tools in preventing catheter-related bloodstream infections and their importance is expected to increase as significant initiatives are expanded to eliminate and make the occurrence of these infections unacceptable. Here we review clinically significant and emerging drug-eluting antimicrobial catheters within the categories of antibiotic, antiseptic, novel bioactive agents and energy-enhanced drug eluting antimicrobial catheters. Important representatives of each category are reviewed from the standpoints of mechanisms of action, physical-chemical properties, safety, in vitro and clinical effectiveness.

Evaluation of the Antimicrobial Efficacy of a Novel Rifampin/Minocycline-Coated, Noncrosslinked Porcine Acellular Dermal Matrix Compared With Uncoated Scaffolds for Soft Tissue Repair

Background Despite meticulous aseptic technique and systemic antibiotics, bacterial colonization of mesh remains a critical issue in hernia repair. A novel minocycline/rifampin tyrosine-coated, noncrosslinked porcine acellular dermal matrix (XenMatrix AB) was developed to protect the device from microbial colonization for up to 7 days. The objective of this study was to evaluate the in vitro and in vivo antimicrobial efficacy of this device against clinically isolated methicillin-resistant Staphylococcus aureus (MRSA) and Escherichia coli. Methods XenMatrix AB was compared with 5 existing uncoated soft tissue repair devices using in vitro methods of zone of inhibition (ZOI) and scanning electron microscopy (SEM) at 24 hours following inoculation with MRSA or E coli These devices were also evaluated at 7 days following dorsal implantation and inoculation with MRSA or E coli (60 male New Zealand white rabbits, n = 10 per group) for viable colony-forming units (CFU), abscess formation and histopathologic response, respectively. Results In vitro studies demonstrated a median ZOI of 36 mm for MRSA and 16 mm for E coli for XenMatrix AB, while all uncoated devices showed no inhibition of bacterial growth (0 mm). SEM also demonstrated no visual evidence of MRSA or E coli colonization on the surface of XenMatrix AB compared with colonization of all other uncoated devices. In vivo XenMatrix AB demonstrated complete inhibition of bacterial colonization, no abscess formation, and a reduced inflammatory response compared with uncoated devices. Conclusion We demonstrated that XenMatrix AB possesses potent in vitro and in vivo antimicrobial efficacy against clinically isolated MRSA and E coli compared with uncoated devices.

APSIC guide for prevention of Central Line Associated Bloodstream Infections (CLABSI)

This document is an executive summary of the APSIC Guide for Prevention of Central Line Associated Bloodstream Infections (CLABSI). It describes key evidence-based care components of the Central Line Insertion and Maintenance Bundles and its implementation using the quality improvement methodology, namely the Plan-Do-Study-Act (PDSA) methodology involving multidisciplinary process and stakeholders. Monitoring of improvement over time with timely feedback to stakeholders is a key component to ensure the success of implementing best practices. A surveillance program is recommended to monitor outcomes and adherence to evidence-based central line insertion and maintenance practices (compliance rate) and identify quality improvement opportunities and strategically targeting interventions for the reduction of CLABSI.

Catheter impregnation, coating or bonding for reducing central venous catheter-related infections in adults

BACKGROUND

The central venous catheter (CVC) is essential in managing acutely ill patients in hospitals. Bloodstream infection is a major complication in patients with a CVC. Several infection control measures have been developed to reduce bloodstream infections, one of which is impregnation of CVCs with various forms of antimicrobials (either with an antiseptic or with antibiotics). This review was originally published in June 2013 and updated in 2016.

OBJECTIVES

Our main objective was to assess the effectiveness of antimicrobial impregnation, coating or bonding on CVCs in reducing clinically-diagnosed sepsis, catheter-related blood stream infection (CRBSI), all-cause mortality, catheter colonization and other catheter-related infections in adult participants who required central venous catheterization, along with their safety and cost effectiveness where data were available. We undertook the following comparisons: 1) catheters with antimicrobial modifications in the form of antimicrobial impregnation, coating or bonding, against catheters without antimicrobial modifications and 2) catheters with one type of antimicrobial impregnation against catheters with another type of antimicrobial impregnation. We planned to analyse the comparison of catheters with any type of antimicrobial impregnation against catheters with other antimicrobial modifications, e.g. antiseptic dressings, hubs, tunnelling, needleless connectors or antiseptic lock solutions, but did not find any relevant studies. Additionally, we planned to conduct subgroup analyses based on the length of catheter use, settings or levels of care (e.g. intensive care unit, standard ward and oncology unit), baseline risks, definition of sepsis, presence or absence of co-interventions and cost-effectiveness in different currencies.

SEARCH METHODS

We used the standard search strategy of the Cochrane Anaesthesia, Critical and Emergency Care Review Group (ACE). In the updated review, we searched the Cochrane Central Register of Controlled Trials (CENTRAL; 2015, Issue 3), MEDLINE (OVID SP; 1950 to March 2015), EMBASE (1980 to March 2015), CINAHL (1982 to March 2015), and other Internet resources using a combination of keywords and MeSH headings. The original search was run in March 2012.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) that assessed any type of impregnated catheter against either non-impregnated catheters or catheters with another type of impregnation in adult patients cared for in the hospital setting who required CVCs. We planned to include quasi-RCT and cluster-RCTs, but we identified none. We excluded cross-over studies.

DATA COLLECTION AND ANALYSIS

We extracted data using the standard methodological procedures expected by Cochrane. Two authors independently assessed the relevance and risk of bias of the retrieved records. We expressed our results using risk ratio (RR), absolute risk reduction (ARR) and number need to treat to benefit (NNTB) for categorical data and mean difference (MD) for continuous data, where appropriate, with their 95% confidence intervals (CIs).

MAIN RESULTS

We included one new study (338 participants/catheters) in this update, which brought the total included to 57 studies with 16,784 catheters and 11 types of impregnations. The total number of participants enrolled was unclear, as some studies did not provide this information. Most studies enrolled participants from the age of 18, including patients in intensive care units (ICU), oncology units and patients receiving long-term total parenteral nutrition. There were low or unclear risks of bias in the included studies, except for blinding, which was impossible in most studies due to the catheters that were being assessed having different appearances. Overall, catheter impregnation significantly reduced catheter-related blood stream infection (CRBSI), with an ARR of 2% (95% CI 3% to 1%), RR of 0.62 (95% CI 0.52 to 0.74) and NNTB of 50 (high-quality evidence). Catheter impregnation also reduced catheter colonization, with an ARR of 9% (95% CI 12% to 7%), RR of 0.67 (95% CI 0.59 to 0.76) and NNTB of 11 (moderate-quality evidence, downgraded due to substantial heterogeneity). However, catheter impregnation made no significant difference to the rates of clinically diagnosed sepsis (RR 1.0, 95% CI 0.88 to 1.13; moderate-quality evidence, downgraded due to a suspicion of publication bias), all-cause mortality (RR 0.92, 95% CI 0.80 to 1.07; high-quality evidence) and catheter-related local infections (RR 0.84, 95% CI 0.66 to 1.07; 2688 catheters, moderate quality evidence, downgraded due to wide 95% CI).In our subgroup analyses, we found that the magnitudes of benefits for impregnated CVCs varied between studies that enrolled different types of participants. For the outcome of catheter colonization, catheter impregnation conferred significant benefit in studies conducted in ICUs (RR 0.70;95% CI 0.61 to 0.80) but not in studies conducted in haematological and oncological units (RR 0.75; 95% CI 0.51 to 1.11) or studies that assessed predominantly patients who required CVCs for long-term total parenteral nutrition (RR 0.99; 95% CI 0.74 to 1.34). However, there was no such variation for the outcome of CRBSI. The magnitude of the effects was also not affected by the participants' baseline risks.There were no significant differences between the impregnated and non-impregnated groups in the rates of adverse effects, including thrombosis/thrombophlebitis, bleeding, erythema and/or tenderness at the insertion site.

AUTHORS' CONCLUSIONS

This review confirms the effectiveness of antimicrobial CVCs in reducing rates of CRBSI and catheter colonization. However, the magnitude of benefits regarding catheter colonization varied according to setting, with significant benefits only in studies conducted in ICUs. A comparatively smaller body of evidence suggests that antimicrobial CVCs do not appear to reduce clinically diagnosed sepsis or mortality significantly. Our findings call for caution in routinely recommending the use of antimicrobial-impregnated CVCs across all settings. Further randomized controlled trials assessing antimicrobial CVCs should include important clinical outcomes like the overall rates of sepsis and mortality.

Antimicrobial peptide melimine coating for titanium and its in vivo antibacterial activity in rodent subcutaneous infection models

Implant-associated infections represent a significant health problem and financial burden on healthcare systems. Current strategies for the treatment or prevention of such infections are still inadequate and new strategies are needed in this era of antibiotic resistance. Melimine, a synthetic antimicrobial peptide with broad spectrum activity against bacteria, fungi and protozoa, has been shown to be a promising candidate for development as antimicrobial coating for biomedical devices and implants. In this study, the in vitro and in vivo antimicrobial activity of melimine-coated titanium was tested. The titanium surface was amine-functionalised with 3-aminopropyltriethoxysilane (APTES) followed by reaction with a bifunctional linker 4-(N-maleimidomethyl)cyclohexane-1-carboxylic 3-sulfo-n-hydroxysuccinimide ester (Sulfo-SMCC) to yield a maleimide functionalised surface. Melimine was then tethered to the surface via a thioether linkage through a Michael addition reaction of the cysteine at its N-terminus with the maleimide moiety. Melimine coating significantly reduced in vitro adhesion and biofilm formation of Pseudomonas aeruginosa by up to 62% and Staphylococcus aureus by up to 84% on the titanium substrates compared to the blank (p < 0.05). The activity was maintained after ethylene oxide gas sterilisation. The coating was also challenged in both mouse and rat subcutaneous infection models and was able to reduce the bacterial load by up to 2 log10 compared to the uncoated surface (p < 0.05). Melimine coating is a promising candidate for development as a surface antimicrobial that can withstand industrial sterilisation while showing good biocompatibility.

Quantitative Comparison of the Antimicrobial Efficiency of Leaching versus Nonleaching Polymer Materials

New antimicrobial materials will be more and more in the focus for hygienic and clinical disease control. Antimicrobial materials have to be distinguished in leaching and nonleaching materials. For many applications of antimicrobial materials on implants the use of nonleaching materials is essential. Therefore, the antimicrobial efficiency of leaching and nonleaching polymers has been investigated quantitatively in vitro in direct comparison on a highly relevant implant of central venous catheters (CVCs) using a well-established called Certika test. This test is especially designed to test antimicrobial properties of leachable and nonleachable materials. This contribution demonstrates that newly developed nonleaching antimicrobial CVCs are equivalent to conventional leaching CVC systems in their antimicrobial performance against gram-positive and gram-negative bacteria, as well as Candida species. The use of new nonleaching antimicrobial polymers as shown here for CVCs represents a different mode of action with the aim to prevent infections also with antibiotic-resistant strains and reduced side effects.

Biogenic selenium nanoparticles inhibit Staphylococcus aureus adherence on different surfaces

The global issue of nosocomial infection is owing to bacterial colonization and biofilm formation on medical devices which primarily affects critically ill and/or immuno-compromised patients and also leads to malfunctioning of the devices. Therefore, it is desirable to prevent bacterial colonization on these devices by coating with a non toxic antimicrobial agent or bacterial adherence inhibitor. Here we have shown Bacillus licheniformis JS2 derived selenium nanoparticles (SeNPs) inhibit Staphylococcus aureus adherence and micro-colony formation on polystyrene, glass, and catheter surface. Results indicated that, the coating of these non toxic biogenic SeNPs, at a concentration of 0.5 mgSe/ml, prohibits bacterial load to more than 60% on glass and catheter surface, when incubated at 4 °C for 24h in phosphate buffered saline. Furthermore, confocal and electron microscopic observations strongly suggested the inhibition of biofilm and micro-colony formation on SeNP coated glass and catheter surfaces when cultured at 37 °C for 72 h in a nutrient rich medium. The study suggests that coating of biogenic SeNPs on medical devices could be an alternative approach for prevention of biofilm related infections.

In vivo biocompatibility and in vitro efficacy of antimicrobial gendine-coated central catheters

Antimicrobial peripherally inserted central catheters (PICCs) might reduce the incidence of central line-associated bloodstream infections (CLABSI). We tested the biocompatibility of a novel gendine-coated (combination of chlorhexidine [CHX] and gentian violet [GV]) PICC in a rabbit intravascular model and tested antimicrobial efficacy in comparison with commercially available minocycline/rifampin (M/R)- and CHX-treated PICCs in an in vitro biofilm colonization model. Gendine-coated and uncoated control PICCs were inserted in the jugular veins of rabbits for 4 days. Histopathological analysis was performed at the end of the 4-day period, and circulating levels of CHX and GV in the blood were measured at different time points using liquid chromatography-mass spectrometry. The antimicrobial efficacy of the PICCs was tested following simulated intravascular indwells of 24 h and 1 week against clinical isolates of methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci, Pseudomonas aeruginosa, Escherichia coli, Acinetobacter baumannii, Enterobacter cloacae, Candida albicans, and Candida glabrata. Rabbits implanted with gendine-coated PICCs exhibited reduced levels of thrombosis and inflammation compared to those of the rabbits with uncoated controls. No GV was detected in blood samples over the entire study period, and trace concentrations of CHX were detected. The gendine-coated PICCs completely prevented the adherence of all pathogens from 24 h to 1 week (P ≤ 0.001), while M/R-treated, CHX-treated, and control PICCs did not. Gendine-coated PICCs were highly effective in preventing biofilm formation of multidrug-resistant pathogenic bacteria and fungi. Gendine-coated PICCs were biocompatible in an intravascular setting. Further, the pharmacokinetic testing established that acute systemic exposures of CHX and GV from the gendine-coated catheters were well within safe levels.

Novel in situ liquefying antimicrobial wrap for preventing tissue expander infections following breast reconstructive surgeries

Breast reconstruction surgeries using tissue expanders (TEs) have highly reported infection rates. To decrease this, we developed a method for disinfecting TEs and surgical pockets, where an antimicrobial solution was applied as a solid film at implantation that subsequently liquefied in situ to provide extended prophylaxis. Silicone discs cut from TEs were covered with gelatin-based films containing minocycline (M) and rifampin (R). Discs and films soaked in saline were subsequently challenged with pathogen at days 1, 3, 7, and 10 and quantified for potential biofilm formation. Discs that were not harvested at each specific time points were refreshed with sterile saline. The discs were challenged with clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA), methicillin-resistant Staphylococcus epidermidis (MRSE), and multidrug-resistant Pseudomonas aeruginosa (MDR-PA). Recoveries of adherent organisms from uncovered silicone discs and gelatin-wrapped discs without added antimicrobial agents were >5 × 10(4) CFU/disc for each organism at each time point. Experimental 0.1%M/0.05%R gelatin films completely inhibited all challenge organisms from attaching to the silicone (p < 0.05) at each time point through day 10. Cytotoxicity was assessed by incubating films with HEK-293T human fibroblasts. There were no significant differences in HEK-293T cell survival between controls and any of the antimicrobial films. The in situ liquefying, bioabsorable, antimicrobial wrap prevented biofilm formation by microorganisms on silicone surfaces in vitro with minimal cytotoxicity.

Comparison of the Duration of Antimicrobial Activity of 2 Different Antimicrobial Central Venous Catheters

We compared the duration of antimicrobial effectiveness of 2 different antimicrobial catheters. The baseline activity of minocycline-rifampin catheters was greater than that of silver-platinum-carbon catheters against Staphylococcus aureus, Staphylococcus epidermidis, and Enterococcus faecalis. The antimicrobial activity of the minocycline-rifampin catheters against these pathogens persisted for up to 12 days, while that of the silver-platinum-carbon catheters was depleted by day 10 (P< .05).

Up for the Challenge: Eliminating Peripherally Inserted Central Catheter Infections in a Complex Patient Population

Background: In response to Medicare reimbursement changes related to central line-associated blood stream infection (CLABSI) effective January 2011, a long-term acute care hospital implemented quality improvement measures to reduce these health care-associated infections. Improvements included alcohol-impregnated port protectors, chlorhexidine gluconate barrier dressings, and didactic/hands on training for care and maintenance. During 2010 the peripherally inserted central line (PICC) team at a neighboring Magnet hospital was asked to partner and develop strategies to further decrease CLABSI.

Methods: The PICC team evaluated the effects of an antimicrobial PICC device in an effort to further reduce the incidence of CLABSI. Upon initiation of the evaluation phase, a database was created to track infection/thrombus rate, insertion-related complications, dwell time, diagnosis, tip location, infusate, vein used, and catheter size. Data collection and reporting was managed by the PICC team.

Results: Across a 2-year period (July 2011–July 2013), 100 devices were inserted with a total of 1,705 line days without any reported CLABSI. The majority of patients received a 4.5F single lumen device (59%). Dwell time ranged from 1 to 57 days with an average of 17 days. To date, no CLABSIs related to this device have been reported at the long-term acute care hospital.

Conclusions: Based on 100 insertions yielding no infections this new product appears to improve patient safety and quality of care. Relative to these results sole use of this product has become their institutional standard for long-term intravenous needs.

In vitro efficacy of a novel active-release antimicrobial coating to eradicate biofilms of Pseudomonas aeruginosa

Implant-related infections are becoming increasingly difficult to treat due to the formation of biofilms on implant surfaces. This study analyzed the in vitro efficacy of a novel antimicrobial coating against biofilms of Pseudomonas aeruginosa, using a flow cell system. Results indicated that P. aeruginosa biofilms were reduced by greater than 8 log10 units in less than 24 h. Data indicated that this active-release coating may be promising for preventing biofilm implant-related infections.

Prevention of biofilm colonization by Gram-negative bacteria on minocycline-rifampin-impregnated catheters sequentially coated with chlorhexidine

Resistant Gram-negative bacteria are increasing central-line-associated bloodstream infection threats. To better combat this, chlorhexidine (CHX) was added to minocycline-rifampin (M/R) catheters. The in vitro antimicrobial activity of CHX-M/R catheters against multidrug resistant, Gram-negative Acinetobacter baumannii, Enterobacter cloacae, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Stenotrophomonas maltophilia was tested. M/R and CHX-silver sulfadiazine (CHX/SS) catheters were used as comparators. The novel CHX-M/R catheters were significantly more effective (P < 0.0001) than CHX/SS or M/R catheters in preventing biofilm colonization and showed better antimicrobial durability.

Catheter impregnation, coating or bonding for reducing central venous catheter-related infections in adults

BACKGROUND

The central venous catheter (CVC) is a commonly used device in managing acutely ill patients in the hospital. Bloodstream infections are major complications in patients who require a CVC. Several infection control measures have been developed to reduce bloodstream infections, one of which is CVC impregnated with various forms of antimicrobials (either with an antiseptic or with antibiotics).

OBJECTIVES

We aimed to assess the effects of antimicrobial CVCs in reducing clinically diagnosed sepsis, established catheter-related bloodstream infection (CRBSI) and mortality.

SEARCH METHODS

We used the standard search strategy of the Cochrane Anaesthesia Review Group (CARG). We searched MEDLINE (OVID SP) (1950 to March 2012), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, Issue 3, 2012), EMBASE (1980 to March 2012), CINAHL (1982 to March 2012) and other Internet resources using a combination of keywords and MeSH headings.

SELECTION CRITERIA

We included randomized controlled trials that assessed any type of impregnated catheter against either non-impregnated catheters or catheters with another impregnation. We excluded cross-over studies.

DATA COLLECTION AND ANALYSIS

We extracted data using the standard methods of the CARG. Two authors independently assessed the relevance and risk of bias of the retrieved records. We expressed our results using risk ratio (RR), absolute risk reduction (ARR) and number need to treat to benefit (NNTB) for categorical data and mean difference (MD) for continuous data where appropriate with their 95% confidence intervals (CIs).

MAIN RESULTS

We included 56 studies with 16,512 catheters and 11 types of antimicrobial impregnations. The total number of participants enrolled was unclear as some studies did not provide this information. There were low or unclear risks of bias in the included studies, except for blinding, which was impossible in most studies due to different appearances between the catheters assessed. Overall, catheter impregnation significantly reduced CRBSI, with an ARR of 2% (95% CI 3% to 1%), RR of 0.61 (95% CI 0.51 to 0.73) and NNTB of 50. Catheter impregnation also reduced catheter colonization, with an ARR of 10% (95% CI 13% to 7%), RR of 0.66 (95% CI 0.58 to 0.75) and NNTB of 10. However, catheter impregnation made no significant difference to the rates of clinically diagnosed sepsis (RR 1.0 (95% CI 0.88 to 1.13)) and all-cause mortality (RR 0.88 (95% CI 0.75 to 1.05)).In our subgroup analyses, we found that the magnitudes of benefits for impregnated CVCs varied in studies that enrolled different types of participants. For the outcome of catheter colonization, catheter impregnation conferred significant benefit in studies conducted in intensive care units (ICUs) (RR 0.68 (95% CI 0.59 to 0.78)) but not in studies conducted in haematological and oncological units (RR 0.75 (95% CI 0.51 to 1.11)) or studies that assessed predominantly patients who required CVCs for long-term total parenteral nutrition (TPN)(RR 0.99 (95% CI 0.74 to 1.34)). However, there was no such variation for the outcome of CRBSI. The magnitude of the effects was also not affected by the participants' baseline risks.There were no significant differences between the impregnated and non-impregnated groups in the rates of adverse effects, including thrombosis/thrombophlebitis, bleeding, erythema and/or tenderness at the insertion site.

AUTHORS' CONCLUSIONS

This review confirms the effectiveness of antimicrobial CVCs in improving such outcomes as CRBSI and catheter colonization. However, the magnitude of benefits in catheter colonization varied according to the setting, with significant benefits only in studies conducted in ICUs. Limited evidence suggests that antimicrobial CVCs do not appear to significantly reduce clinically diagnosed sepsis or mortality. Our findings call for caution in routinely recommending the use of antimicrobial-impregnated CVCs across all settings. Further randomized controlled trials assessing antimicrobial CVCs should include important clinical outcomes like the overall rates of sepsis and mortality.

In vitro activity and durability of a combination of an antibiofilm and an antibiotic against vascular catheter colonization

Catheter-associated infections can cause severe complications and even death. Effective antimicrobial modification of catheters that can prevent device colonization has the potential of preventing clinical infection. We studied in vitro the antimicrobial activities of central venous catheters impregnated with N-acetylcysteine (NAC), an antibiofilm agent, and a broad-spectrum antibiotic against a range of important clinical pathogens. NAC-levofloxacin-impregnated (NACLEV) catheters were also evaluated for their antiadherence activity. NACLEV catheters produced the most active and durable antimicrobial effect against both Gram-positive and Gram-negative isolates and significantly reduced colonization (P < 0.0001) by all tested pathogens compared to control catheters. These in vitro results suggest that this antimicrobial combination can potentially be used to combat catheter colonization and catheter-associated infection.

In vivo efficacy of a silicone‒cationic steroid antimicrobial coating to prevent implant-related infection

Active release antimicrobial coatings for medical devices have been developed to prevent and treat biofilm implant-related infections. To date, only a handful of coatings have been put into clinical use, with limited success. In this study, a novel antimicrobial compound was incorporated into a silicone (polydimethylsiloxane or PDMS) polymer to develop a novel active release coating that addressed several limitations of current device coatings. The efficacy of this coating was optimized using an in vitro flow cells system, then translated to an animal model of a simulated Type IIIB open fracture wherein well-established biofilms were used as initial inocula. Results indicated that the novel coating was able to prevent infection in 100% (9/9) of animals that were treated with biofilms and the novel coating (treatment group). In contrast, 100% (9/9) of animals that were inoculated with biofilms and not treated with the coating (positive control), did develop infection. Nine animals were used as negative controls, i.e., those that were not treated with biofilms, and showed a rate of infection of 11% (1/9). Eight animals were treated with the novel coating only to determine its effect on host tissue. Results indicated that the novel active release coating may have significant promise for future application to prevent biofilm implant-related infections in patients.

Infection prevention in the intensive care unit: review of the recent literature on the management of invasive devices

Over the last 5 y, clinical trials investigating products, procedures, and treatments aimed at preventing infections in the intensive care unit have been described. The findings of these studies appear to confirm the effectiveness of certain preventive procedures. With regard to ventilator-associated pneumonia, the efficacies of decontamination of the oral cavity, continuous suction of subglottic secretions, positioning of the patient, selective decontamination of the digestive tract, and (for higher-risk patients) endotracheal tubes coated with silver, have been demonstrated. Medicated catheters and chlorhexidine-based dressings have been found useful for catheter-related bloodstream infections, and medical catheters have also been shown to be efficacious against urinary tract infections. All these procedures can be incorporated into departmental protocols for the prevention of nosocomial infections in the intensive care unit.

Anti-infective external coating of central venous catheters: a randomized, noninferiority trial comparing 5-fluorouracil with chlorhexidine/silver sulfadiazine in preventing catheter colonization

OBJECTIVE

The antimetabolite drug, 5-fluorouracil, inhibits microbial growth. Coating of central venous catheters with 5-fluorouracil may reduce the risk of catheter infection. Our objective was to compare the safety and efficacy of central venous catheters externally coated with 5-fluorouracil with those coated with chlorhexidine and silver sulfadiazine.

DESIGN

Prospective, single-blind, randomized, active-controlled, multicentered, noninferiority trial.

SETTING

Twenty-five US medical center intensive care units.

PATIENTS

A total of 960 adult patients requiring central venous catheterization for up to 28 days.

INTERVENTIONS

Patients were randomized to receive a central venous catheter externally coated with either 5-fluorouracil (n = 480) or chlorhexidine and silver sulfadiazine (n = 480).

MEASUREMENTS AND MAIN RESULTS

The primary antimicrobial outcome was a dichotomous measure (<15 colony-forming units or ≥ 15 colony-forming units) for catheter colonization determined by the roll plate method. Secondary antimicrobial outcomes included local site infection and catheter-related bloodstream infection. Central venous catheters coated with 5-fluorouracil were noninferior to chlorhexidine and silver sulfadiazine coated central venous catheters with respect to the incidence of catheter colonization (2.9% vs. 5.3%, respectively). Local site infection occurred in 1.4% of the 5-fluorouracil group and 0.9% of the chlorhexidine and silver sulfadiazine group. No episode of catheter-related bloodstream infection occurred in the 5-fluorouracil group, whereas two episodes were noted in the chlorhexidine and silver sulfadiazine group. Only Gram-positive organisms were cultured from 5-fluorouracil catheters, whereas Gram-positive bacteria, Gram-negative bacteria, and Candida were cultured from the chlorhexidine and silver sulfadiazine central venous catheters. Adverse events were comparable between the two central venous catheter coatings.

CONCLUSIONS

Our results suggest that central venous catheters externally coated with 5-fluorouracil are a safe and effective alternative to catheters externally coated with chlorhexidine and silver sulfadiazine when used in critically ill patients.

A multimodal approach to central venous catheter hub care can decrease catheter-related bloodstream infection

BACKGROUND

This study was conducted to investigate decreases in catheter-related bloodstream infections (CRBSIs) through an evidence-based multimodal intervention.

METHODS

This was a prospective interventional study of neonates with a central venous catheter (CVC) from a neonatal intensive care unit database, involving implementation of a multimodal approach to central venous catheter hub care using 2% chlorhexidine in 70% isopropyl alcohol and education of medical staff by audiovisual presentations. CRBSI rates in the pre-intervention period and postintervention period were compared.

RESULTS

A total of 373 patients with a CVC (163 in the preintervention period and 210 in the postintervention period) were studied. Patient demographic and clinical characteristics were similar in the 2 periods. Extremely low birth weight infants constituted 40% of the cohort in the preintervention period and 38% of the cohort in the postintervention period. The CRBSI rate in patients with a umbilical artery catheter and an umbilical vein catheter decreased from 15/1000 catheter-days to 10/1000 catheter-days (odds ratio [OR], 0.47; 95% confidence interval [CI], 0.17-0.91). The CRBSI rate in patients with a peripherally inserted central catheter decreased from 23/1000 catheter-days to 10/1000 catheter-days (OR, 0.33; 95% CI, 0.12-0.91). These decreased CRBSI rates were sustained despite high device utilization. The incidence of gram-negative septicemia also decreased. Ten CRBSIs were prevented by this multimodal approach, representing significant health care cost savings.

CONCLUSION

This study demonstrates significant decreases in CRBSI rate for all catheter types and birth weight categories associated with the multimodal intervention. Audiovisual education is an effective tool for practice change. Reeducation and compliance monitoring should be part of all nosocomial infection prevention strategies, resulting in significant savings in health care costs.

Effectiveness of different central venous catheters for catheter-related infections: a network meta-analysis

We aimed to compare the effectiveness of various catheters for prevention of catheter-related infection and to evaluate whether specific catheters are superior to others for reducing catheter-related infections. We identified randomised, controlled trials that compared different types of central venous catheter (CVC), evaluating catheter-related infections in a systematic search of articles published from January 1996 to November 2009 via Medline, Embase, Web of Science, and the Cochrane Central Register of Controlled Trials. Network meta-analysis with a mixed treatment comparison method using Bayesian Markov Chain Monte Carlo simulation was used to combine direct within-trial, between-treatment comparisons with indirect trial evidence. Forty-eight clinical trials (12 828 CVCs) investigating 10 intervention catheters contributed to the analyses. For prevention of CVC colonisation, adjusted silver iontophoretic catheters (odds ratio: 0.58; 95% confidence interval: 0.33-0.95), chlorhexidine and silver sulfadiazine catheters (0.49; 0.36-0.64), chlorhexidine and silver sulfadiazine blue plus catheters (0.37; 0.17-0.69), minocycline-rifampicin catheters (0.28; 0.17-0.43) and miconazole-rifampicin catheters (0.11; 0.02-0.33) were associated with a significantly lower rate of catheter colonisation compared with standard catheters. For prevention of CRBSI, adjusted heparin-bonded catheters (0.20; 0.06-0.44) and minocycline-rifampicin catheters (0.18; 0.08-0.34) were associated with a significantly lower rate of CRBSI with standard catheters. Rifampicin-based impregnated catheters seem to be better for prevention of catheter-related infection compared with the other catheters.

[Epidemiology of the primary and vascular catheter-related bacteriemias in critical patients admitted to an Intensive Medicine Department]

OBJECTIVE

In recent years, changes have occurred in the setting of bacteriemia related with the use of vascular catheters (BVC) and with the appearance of multiresistant gram positive cocci (MR-GPC), knowledge of the limitations regarding the antibiotics used most for their treatment (glycopeptides) and the appearance of new antibiotics active against these pathogens. This article analyzes the evolution of the rates, etiologies and markers of multiresistance of the most common pathogens in the BVC (including the primary bacteriemias) in the Spanish Intensive Medicine Departments (ICU).

MATERIAL AND METHODS

A multicenter, prospective, observational study of incidence, with voluntary participation, was conducted. A total of 74, 105, 112 and 121 ICUs belonging to 71, 97, 103 and 112 hospitals, respectively, collaborated including the years 2005-2008. The information included in the ENVIN-HELICS registry was used.

RESULTS

The rates of this complication have decreased and are now at about 5 episodes per 1,000 days of central venous catheter (CVC). One third of the episodes occur with significant systemic response (severe sepsis or septic shock). The MR-GPC were the most frequent, however Gram-negative bacilli (GNB) were identified in 30% of the cases and fungi (different species of Candida) in 6%. Staphylococcus epidermidis and coagulase-negative, methicillin-resistant staphylococci (CNS) persist in a proportion greater than 80%, while methicillin-resistance S. aureus have decreased to less than 40%.

CONCLUSIONS

The empirical treatment in situations of extreme seriousness should consider coverage of the most frequent pathogens such as the MR-GPC and GNB and in special conditions, the fungi.

Access technique and its problems in parenteral nutrition - Guidelines on Parenteral Nutrition, Chapter 9

Catheter type, access technique, and the catheter position should be selected considering to the anticipated duration of PN aiming at the lowest complication risks (infectious and non-infectious). Long-term (>7-10 days) parenteral nutrition (PN) requires central venous access whereas for PN <3 weeks percutaneously inserted catheters and for PN >3 weeks subcutaneous tunnelled catheters or port systems are appropriate. CVC (central venous catheter) should be flushed with isotonic NaCl solution before and after PN application and during CVC occlusions. Strict indications are required for central venous access placement and the catheter should be removed as soon as possible if not required any more. Blood samples should not to be taken from the CVC. If catheter infection is suspected, peripheral blood-culture samples and culture samples from each catheter lumen should be taken simultaneously. Removal of the CVC should be carried out immediately if there are pronounced signs of local infection at the insertion site and/or clinical suspicion of catheter-induced sepsis. In case PN is indicated for a short period (max. 7-10 days), a peripheral venous access can be used if no hyperosmolar solutions (>800 mosm/L) or solutions with a high titration acidity or alkalinity are used. A peripheral venous catheter (PVC) can remain in situ for as long as it is clinically required unless there are signs of inflammation at the insertion site.

[Femoral venous catheterization. Does it really need to be avoided?]

The guidelines to prevent central venous catheter related bloodstream infections (CVCBSI) of the Centers for Disease Control and Prevention (CDC) of 2002, Sociedad Española de Medicina Intensiva, Crítica y Unidades Coronarias/ Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica (SEMICYUC/SEIMC) of 2004, and the recently published guidelines of the Society for Healthcare Epidemiology of America/Infectious Diseases Society of America (SHEA(IDSA) of 2008 have recommended using the subclavian vein and avoiding the use of the femoral vein. They also recommend considering the use of antiseptic- or antimicrobial-impregnated CVCs for hospital units or groups of patients with a high incidence of CVCBSI. When implementing these guidelines, two questions could be asked: 1) Could the abuse of the subclavian vein and avoiding the use of the femoral vein imply a decrease in the incidence of CVCBSI, but an increase in the rate of mechanical complications as pneumothorax and/or hemothorax? 2) Couldn't antimicrobial-impregnated CVCs be used to prevent CVCBSI when the femoral venous access is used?

[Bacterial infections in critically ill patients: review of studies published between 2006 and 2008]

A systematic revision of medical publications between 2006 and 2008 regarding bacterial infections that affect the critical patients was performed. Four subjects were selected: Community-acquired pneumonia, ventilator-associated pneumonia, catheter-related bloodstream infection and new antimicrobial treatments. When dealing with community-acquired pneumonia and due to the absence of completely reliable standards, it is necessary to follow the locally adapted guidelines of clinical practice, to identify patients related to the health-care system and admit patients to the ICU in accordance with the criteria. Regarding the etiological diagnosis of ventilator-associated pneumonia, any microbiological information available must be used. Due to the risk of multidrug bacteria, combined empiric therapy should be initiated immediately and then mono-therapy adjusted to the antibiogram should be established. Already established measures for mechanical ventilation associated pneumonia and catheter-related bacteriemias, which have been effective, should be implemented. The empirical treatment of catheter-related bacteremia must be directed towards the most probable pathogens according to the puncture site. The most recently sold antibiotics are basically directed towards multidrug gram positive resistant bacteria. However, for the treatment of gram negative resistant bacilli, the use of the new antimicrobials must be combined with a new evaluation of the antibiotics that have been used for years and the possibility of choosing different administration forms.

Catheter-related bloodstream infection

Catheter-related bloodstream infections (CR-BSIs) are a common, frequently preventable complication of central venous catheterization. CR-BSIs can be prevented by strict attention to insertion and maintenance of central venous catheters and removing unneeded catheters as soon as possible. Antiseptic- or antibiotic-impregnated catheters are also an effective tool to prevent infections. The diagnosis of CR-BSI is made largely based on culture results. CR-BSIs should always be treated with antibiotics, and except in rare circumstances the infected catheter needs to be removed.

The clinical effectiveness of central venous catheters treated with anti-infective agents in preventing catheter-related bloodstream infections: a systematic review

OBJECTIVES

To assess the clinical effectiveness of central venous catheters (CVCs) treated with anti-infective agents (AI-CVCs) in preventing catheter-related bloodstream infections (CRBSI).

DATA SOURCES

MEDLINE (OVID), EMBASE, SCI//Web of Science, SCI/ISI Proceedings, and the Cochrane Library.

STUDY SELECTION

A systematic review of the literature was conducted using internationally recognized methodology. All included articles were reports of randomized controlled trials comparing the clinical effectiveness of CVCs treated with AI-CVCs with either standard CVCs or another anti-infective treated catheter. Articles requiring in-house preparation of catheters or that only reported interim data were excluded.

DATA EXTRACTION

Data extraction was carried out independently and crosschecked by two reviewers using a pretested data extraction form.

DATA SYNTHESIS

Meta-analyses were conducted to assess the effectiveness of AI-CVCs in preventing CRBSI, compared with standard CVCs. Results are presented in forest plots with 95% confidence intervals.

RESULTS

Thirty-eight randomized controlled trials met the inclusion criteria. Methodologic quality was generally poor. Meta-analyses of data from 27 trials assessing CRBSI showed a strong treatment effect in favor of AI-CVCs (odds ratio 0.49 (95% confidence interval 0.37-0.64) fixed effects, test for heterogeneity, chi-square = 28.78, df = 26, p = 0.321, I = 9.7). Results subgrouped by the different types of anti-infective treatments generally demonstrated treatment effects favoring the treated catheters. Sensitivity analyses investigating the effects of methodologic differences showed no differences to the overall conclusions of the primary analysis.

CONCLUSION

AI-CVCs appear to be effective in reducing CRBSI compared with standard CVCs. However, it is important to establish whether this effect remains in settings where infection-prevention bundles of care are established as routine practice. This review does not address this question and further research is required.

The use of rifampicin-miconazole-impregnated catheters reduces the incidence of femoral and jugular catheter-related bacteremia

BACKGROUND

The guidelines of the Centers for Disease Control and Prevention do not recommend the use of an antimicrobial- or antiseptic-impregnated catheter for short-term use. In previous studies, we have found a higher incidence of central venous catheter-related bacteremia among patients with femoral and central jugular accesses than among patients with other venous accesses.

OBJECTIVE

The objective of our study was to determine the incidence of central venous catheter-related bacteremia associated with rifampicin-miconazole-impregnated catheters and standard catheters in patients with femoral and central jugular venous accesses.

METHODS

This was a cohort study, conducted in the 24-bed polyvalent medical-surgical intensive care unit of a university hospital. We included patients who were admitted to the intensive care unit from 1 June 2006 through 30 September 2007 and who underwent femoral or central jugular venous catheterization.

RESULTS

We inserted 184 femoral (73 rifampicin-miconazole-impregnated catheters and 111 standard catheters) and 241 central jugular venous catheters (114 rifampicin-miconazole-impregnated catheters and 127 standard catheters). We found a lower rate of central venous catheter-related bacteremia associated with rifampicin-miconazole-impregnated catheters than with standard catheters among patients with femoral access (0 vs. 8.62 cases per 1000 catheter-days; odds ratio, 0.13; 95% confidence interval, 0.00-0.86; P = .03) and among patients with central internal jugular access (0 vs. 4.93 cases per 1000 catheter-days; odds ratio, 0.13; 95% confidence interval, 0.00-0.93; P = .04).

CONCLUSIONS

Rifampicin-minonazole-impregnated catheters are associated with a statistically significant reduction in the incidence of catheter-related bacteremia in patients with short-term catheter use at the central jugular and femoral sites.