NIHR Signal Medication impregnated dressings for central venous catheters reduce the number of bloodstream infections, but the quality of the research is low

Published on 18 November 2015

This review found that securing central venous catheters with dressings impregnated with medication reduced the number of bloodstream infections compared to other dressings. The frequency of infection was particularly reduced with chlorhexidine antiseptic dressings. Based on the study population it is anticipated that rates might fall from about 2.8 infections per 100 people using usual dressing types to 1.7 per 100 people using medication impregnated dressings. The overall quality of evidence to answer these important questions is poor or very poor. This finding aligns with the recommendations to use chlorhexidine dressings by NICE and NHS England’s “epic3” guideline. There was not enough evidence to assess other dressings or devices, and the review did not look at cost-effectiveness. The results mostly come from, and apply to, short-term catheter use in intensive care settings.

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Why was this study needed?

It is estimated that about 300,000 patients a year in England acquire a healthcare-associated infection as a result of care within the NHS, at a cost of approximately £1 billion a year.

A central venous catheter is a long thin tube that is inserted into a large vein through which central venous pressure can be monitored or fluids, nutrients, blood, and drugs can be given to a patient. They are often used in the short term in intensive care units and acute care wards. Those used for longer terms, such as in people with cancer receiving chemotherapy, are often constructed differently and may be tunnelled under the skin to reduce infection. Their use avoids the need for repeated injections, but their insertion and long-term use carries the risk of infection being introduced into the bloodstream. Dressings or securement devices that hold them in place may have a role in cutting this infection risk.

New products are always coming onto the market and it is important that the evidence on what works best remains current. This Cochrane systematic review compared the effectiveness of dressings and securement devices for central venous catheters in minimising the number of catheter-related bloodstream infections.

What did this study do?

This was a systematic review with meta-analyses of 22 randomised controlled trials that included a total of 7,436 participants. Between them the trials compared nine different types of securement device or dressing. Most studies were in intensive care units where catheters are used for a relatively short period of time. Studies were from 25 countries, though none were from the UK.

Standard high-quality Cochrane systematic review methods were used. However, most studies were poorly reported, had unclear risk of bias and gave varied results. The pooled results had wide confidence intervals, meaning we can have less confidence in the exact risk estimate. Many of the meta-analyses included only a few trials – variety in the dressings and devices used, and outcomes measured, meant pooling more trials would not make sense. Overall the results need to be treated with caution.

What did it find?

  • Medication-impregnated dressings (chlorhexidine, iodine or silver-impregnated dressings) reduced the occurrence of catheter-related bloodstream infection by 40% compared to all other dressing types, from 2.8% to 1.7% (RR 0.60, 95% CI 0.39 to 0.93). This was from a meta-analysis of six trials, most of which looked at dressings impregnated with chlorhexidine gluconate.
  • Chlorhexidine gluconate-impregnated dressings halved the frequency of bloodstream infections per 1000 patient days compared with standard polyurethane dressings (RR 0.51, 95% CI 0.33 to 0.78). This was from a meta-analysis of four studies.
  • There was no difference in skin irritation or damage between chlorhexidine gluconate-impregnated dressings and polyurethane dressings. However, this outcome was only examined in two studies in children and new born infants.
  • There was not enough evidence to assess other devices or dressings, such as those impregnated with silver or iodine.

What does current guidance say on this issue?

NICE guidance from 2012 recommends that the central venous catheter insertion site and surrounding skin should be decontaminated during dressing changes using chlorhexidine gluconate in 70% alcohol, and that a sterile transparent semipermeable (polyurethane) membrane dressing should cover the vascular access device insertion site.

NHS England’s “epic3” guidance similarly recommends cleaning the skin at the insertion site with chlorhexidine gluconate in 70% alcohol. They also advise chlorhexidine-impregnated sponge dressings for adult patients with a central venous catheter as a strategy to reduce bloodstream infection. If bloodstream infection rates remain above an agreed benchmark, they additionally recommend the use of an antimicrobial-impregnated central venous access device for adult patients whose catheter is expected to remain in place for more than five days.

What are the implications?

The trials in this review were often poorly reported and gave imprecise results. However, the weight of the evidence does suggest that chlorhexidine gluconate-impregnated dressings are likely to reduce central venous catheter-related bloodstream infections compared to polyurethane and other dressings. However, most of the evidence for this conclusion comes from short-use in intensive care units. The results may not apply to long-term venous catheter use.

New products are continually becoming commercially available, and it is important that this and other similarly scoped reviews are kept up to date.

Citation

Ullman AJ, Cooke ML, Mitchell M, et al. Dressings and securement devices for central venous catheters (CVC). Cochrane Database Syst Rev. 2015;9:CD010367.

Why was this study needed?

It is estimated that about 300,000 patients a year in England acquire a healthcare-associated infection as a result of care within the NHS, at a cost of approximately £1 billion a year.

A central venous catheter is a long thin tube that is inserted into a large vein through which central venous pressure can be monitored or fluids, nutrients, blood, and drugs can be given to a patient. They are often used in the short term in intensive care units and acute care wards. Those used for longer terms, such as in people with cancer receiving chemotherapy, are often constructed differently and may be tunnelled under the skin to reduce infection. Their use avoids the need for repeated injections, but their insertion and long-term use carries the risk of infection being introduced into the bloodstream. Dressings or securement devices that hold them in place may have a role in cutting this infection risk.

New products are always coming onto the market and it is important that the evidence on what works best remains current. This Cochrane systematic review compared the effectiveness of dressings and securement devices for central venous catheters in minimising the number of catheter-related bloodstream infections.

What did this study do?

This was a systematic review with meta-analyses of 22 randomised controlled trials that included a total of 7,436 participants. Between them the trials compared nine different types of securement device or dressing. Most studies were in intensive care units where catheters are used for a relatively short period of time. Studies were from 25 countries, though none were from the UK.

Standard high-quality Cochrane systematic review methods were used. However, most studies were poorly reported, had unclear risk of bias and gave varied results. The pooled results had wide confidence intervals, meaning we can have less confidence in the exact risk estimate. Many of the meta-analyses included only a few trials – variety in the dressings and devices used, and outcomes measured, meant pooling more trials would not make sense. Overall the results need to be treated with caution.

What did it find?

  • Medication-impregnated dressings (chlorhexidine, iodine or silver-impregnated dressings) reduced the occurrence of catheter-related bloodstream infection by 40% compared to all other dressing types, from 2.8% to 1.7% (RR 0.60, 95% CI 0.39 to 0.93). This was from a meta-analysis of six trials, most of which looked at dressings impregnated with chlorhexidine gluconate.
  • Chlorhexidine gluconate-impregnated dressings halved the frequency of bloodstream infections per 1000 patient days compared with standard polyurethane dressings (RR 0.51, 95% CI 0.33 to 0.78). This was from a meta-analysis of four studies.
  • There was no difference in skin irritation or damage between chlorhexidine gluconate-impregnated dressings and polyurethane dressings. However, this outcome was only examined in two studies in children and new born infants.
  • There was not enough evidence to assess other devices or dressings, such as those impregnated with silver or iodine.

What does current guidance say on this issue?

NICE guidance from 2012 recommends that the central venous catheter insertion site and surrounding skin should be decontaminated during dressing changes using chlorhexidine gluconate in 70% alcohol, and that a sterile transparent semipermeable (polyurethane) membrane dressing should cover the vascular access device insertion site.

NHS England’s “epic3” guidance similarly recommends cleaning the skin at the insertion site with chlorhexidine gluconate in 70% alcohol. They also advise chlorhexidine-impregnated sponge dressings for adult patients with a central venous catheter as a strategy to reduce bloodstream infection. If bloodstream infection rates remain above an agreed benchmark, they additionally recommend the use of an antimicrobial-impregnated central venous access device for adult patients whose catheter is expected to remain in place for more than five days.

What are the implications?

The trials in this review were often poorly reported and gave imprecise results. However, the weight of the evidence does suggest that chlorhexidine gluconate-impregnated dressings are likely to reduce central venous catheter-related bloodstream infections compared to polyurethane and other dressings. However, most of the evidence for this conclusion comes from short-use in intensive care units. The results may not apply to long-term venous catheter use.

New products are continually becoming commercially available, and it is important that this and other similarly scoped reviews are kept up to date.

Citation

Ullman AJ, Cooke ML, Mitchell M, et al. Dressings and securement devices for central venous catheters (CVC). Cochrane Database Syst Rev. 2015;9:CD010367.

Dressings and securement devices for central venous catheters (CVC)

Published on 12 September 2015

Ullman, A. J.,Cooke, M. L.,Mitchell, M.,Lin, F.,New, K.,Long, D. A.,Mihala, G.,Rickard, C. M.

Cochrane Database Syst Rev Volume 9 , 2015

BACKGROUND: Central venous catheters (CVCs) play a vital role in the management of acute and chronic illness. Dressings and securement devices must ensure CVCs do not dislodge or fall out, provide a barrier protection from microbial colonisation and infection, and be comfortable for the patient. There is a large range of dressing and securement products available for clinicians to use. OBJECTIVES: To compare the available dressing and securement devices for CVCs, in terms of catheter-related bloodstream infection (BSI), catheter colonisation, entry- and exit-site infection, skin colonisation, skin irritation, failed catheter securement, dressing condition and mortality. SEARCH METHODS: In June 2015 we searched: The Cochrane Wounds Group Specialised Register; The Cochrane Central Register of Controlled Trials (CENTRAL); The Database of Abstracts of Reviews of Effects (DARE); NHS Economic Evaluation Database (NHSEED); Ovid MEDLINE; Ovid MEDLINE (In-Process & Other Non-Indexed Citations); Ovid EMBASE; EBSCO CINAHL; six clinical trial registries and reference lists of identified trials. There were no restrictions based on language or date of publication or study setting. SELECTION CRITERIA: We included randomised controlled trials that evaluated the effects of dressing and securement devices for CVCs. All types of CVCs were included, i.e. short- and long-term CVCs, tunnelled and non-tunnelled, port-a-caths, haemodialysis catheters, and peripherally-inserted central catheters (PICCs). DATA COLLECTION AND ANALYSIS: We used standard Cochrane Collaboration methods including independent review of titles and abstracts for relevance, data extraction, and risk of bias assessment of the included studies by two review authors. Results are expressed using risk ratio (RR) for categorical data with 95% confidence intervals (CIs). For outcomes best presented as a rate-per-time-period, rate ratios and standard errors have been used. We performed multiple treatment meta-analyses to rank the effectiveness of each intervention for each outcome. MAIN RESULTS: We included 22 studies involving 7436 participants comparing nine different types of securement device or dressing. All included studies were at unclear or high risk of performance bias due to the different appearances of the dressings and securement devices. The extent of blinding of outcome assessment was unclear in most studies. The quality of evidence varied between different comparisons and outcomes. We mainly downgraded the quality of evidence for imprecision, indirectness, risk of bias and inconsistency.It is unclear whether there is a difference in the rate of catheter-related BSI between securement with gauze and tape and standard polyurethane (SPU) (RR 0.64, 95% CI 0.26 to 1.63, low quality evidence), or between chlorhexidine gluconate-impregnated (CGI) dressings and SPU (RR 0.65, 95% CI 0.40 to 1.05, moderate quality evidence). There is high quality evidence that medication-impregnated dressings reduce the incidence of catheter-related BSI relative to all other dressing types (RR 0.60, 95% CI 0.39 to 0.93).There is moderate quality evidence that CGI dressings reduce the frequency of catheter-related BSI per 1000 patient days compared with SPU dressings (RR 0.51, 95% CI 0.33 to 0.78).There is moderate quality evidence that catheter tip colonisation is reduced with CGI dressings compared with SPU dressings (RR 0.58, 95% CI 0.47 to 0.73), but the relative effects of gauze and tape and SPU are unclear (RR 0.95, 95% CI 0.51 to 1.77, very low quality evidence). It is unclear if there is a difference in rates of skin irritation or damage when CGI dressings are compared with SPU dressings (moderate quality evidence) (RR 11.17, 95% CI 0.84 to 149.48).A multiple treatment meta-analysis found sutureless securement devices as likely to be the most effective at reducing the incidence of catheter-related BSI (low quality evidence), with CGI dressings ranked second (low quality evidence). AUTHORS' CONCLUSIONS: Medication-impregnated dressing products reduce the incidence of catheter-related BSI relative to all other dressing types. There is some evidence that CGI dressings, relative to SPU dressings, reduce catheter-related BSI for the outcomes of frequency of infection per 1000 patient days, risk of catheter tip colonisation and possibly risk of catheter-related BSI. A multiple treatment meta-analysis found that sutureless securement devices are likely to be the most effective at reducing catheter-related BSI though this is low quality evidence. Most studies were conducted in intensive care unit (ICU) settings. More, high quality research is needed regarding the relative effects of dressing and securement products for CVCs. Future research may adjust the estimates of effect for the products included in this review and is needed to assess the effectiveness of new products.

Expert commentary

This review highlights the need for further studies in vascular access to ensure clinical practice is as safe as it can be. The use of chlorhexidine gluconate and impregnated patches under film dressings should be seen as an adjunct to best practice in central venous catheter care where a strategy is required to reduce infection rates. It is worth noting that whatever product is placed under the dressing, over the insertion site, reducing the risk of intraluminal catheter related blood stream infection is only achieved by good aseptic line care and regular documented surveillance of the central venous catheter device.

Andrew Barton, Advanced Nurse Practitioner for Vascular Access and IV Therapy, Frimley Health NHS Foundation Trust