A.L. Casey

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.

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

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

The Antimicrobial Efficacy of Copper Alloy Furnishing in the Clinical Environment: A Crossover Study

OBJECTIVE To determine whether copper incorporated into hospital ward furnishings and equipment can reduce their surface microbial load. DESIGN A crossover study. SETTING Acute care medical ward with 19 beds at a large university hospital. METHODS Fourteen types of frequent-touch items made of copper alloy were installed in various locations on an acute care medical ward. These included door handles and push plates, toilet seats and flush handles, grab rails, light switches and pull cord toggles, sockets, overbed tables, dressing trolleys, commodes, taps, and sink fittings. Their surfaces and those of equivalent standard items on the same ward were sampled once weekly for 24 weeks. The copper and standard items were switched over after 12 weeks of sampling to reduce bias in usage patterns. The total aerobic microbial counts and the presence of indicator microorganisms were determined. RESULTS Eight of the 14 copper item types had microbial counts on their surfaces that were significantly lower than counts on standard materials. The other 6 copper item types had reduced microbial numbers on their surfaces, compared with microbial counts on standard items, but the reduction did not reach statistical significance. Indicator microorganisms were recovered from both types of surfaces; however, significantly fewer copper surfaces were contaminated with vancomycin-resistant enterococci, methicillin-susceptible Staphylococcus aureus, and coliforms, compared with standard surfaces. CONCLUSIONS Copper alloys (greater than or equal to 58% copper), when incorporated into various hospital furnishings and fittings, reduce the surface microorganisms. The use of copper in combination with optimal infection-prevention strategies may therefore further reduce the risk that patients will acquire infection in healthcare environments.

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.

Impact of surgical site infection on healthcare costs and patient outcomes: a systematic review in six European countries

BACKGROUND Surgical site infections (SSIs) are associated with increased morbidity and mortality. Furthermore, SSIs constitute a financial burden and negatively impact on patient quality of life (QoL). AIM To assess, and evaluate the evidence for, the cost and health-related QoL (HRQoL) burden of SSIs across various surgical specialties in six European countries. METHODS Electronic databases and conference proceedings were systematically searched to identify studies reporting the cost and HRQoL burden of SSIs. Studies published post 2005 in France, Germany, the Netherlands, Italy, Spain, and the UK were eligible for data extraction. Studies were categorized by surgical specialty, and the primary outcomes were the cost of infection, economic evaluations, and HRQoL. FINDINGS Twenty-six studies met the eligibility criteria and were included for analysis. There was a paucity of evidence in the countries of interest; however, SSIs were consistently associated with elevated costs, relative to uninfected patients. Several studies reported that SSI patients required prolonged hospitalization, reoperation, readmission, and that SSIs increased mortality rates. Only one study reported QoL evidence, the results of which demonstrated that SSIs reduced HRQoL scores (EQ-5D). Hospitalization reportedly constituted a substantial cost burden, with additional costs arising from medical staff, investigation, and treatment costs. CONCLUSION Disparate reporting of SSIs makes direct cost comparisons difficult, but this review indicated that SSIs are extremely costly. Thus, rigorous procedures must be implemented to minimize SSIs. More economic and QoL studies are required to make accurate cost estimates and to understand the true burden of SSIs.

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 β-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.

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.

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

BackgroundAntimicrobial 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).MethodsWe 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.ResultsThe 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.ConclusionCommercially-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.

Antimicrobial activity and skin permeation of iodine present in an iodine-impregnated surgical incise drape

OBJECTIVES The antimicrobial efficacy of an iodine-impregnated incise drape against MRSA was evaluated in a skin model. The permeation of iodine from this drape into the skin was also assessed. METHODS The antimicrobial efficacy was evaluated in ex vivo studies following application of the surgical incise drape for various times on the surface of donor skin, which was inoculated with either 1 × 10(3) or 1 × 10(6) cfu MRSA/cm(2) skin and mounted on Franz diffusion cells. In some experiments the MRSA-inoculated skin was pre-incubated for 18 h at room temperature prior to applying the drape. Permeation of iodine into the skin using this model was also determined following application of the incise drape for 6 h. RESULTS The iodine-impregnated drape demonstrated antimicrobial activity compared with the non-use of drape. This reached significance when a high inoculum of MRSA was applied with no pre-incubation period and when a low inoculum of MRSA was applied with a pre-incubation period (P = 0.002 and P = 0.014, respectively). Furthermore, in experiments wherein a high inoculum of MRSA was applied with no pre-incubation period, the iodine-impregnated drape demonstrated superior antimicrobial activity compared with the use of a non-antimicrobial drape (P < 0.001). MIC and MBC values of iodine were attained to 1500 μm below the skin surface. CONCLUSIONS The iodine-impregnated surgical incise drape had detectable antimicrobial activity. Furthermore, iodine penetrated into the deeper layers of the skin. This property should suppress microbial regrowth at and around a surgical incision site, making its use preferable to the use of a standard drape or non-use of a drape.