This is a plain English summary of an original research article
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.
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.
Ullman AJ, Cooke ML, Mitchell M, et al. Dressings and securement devices for central venous catheters (CVC). Cochrane Database Syst Rev. 2015;9:CD010367.
Loveday HP, Wilson JA, Pratt RJ, et al. epic3: National Evidence-Based Guidelines for Preventing Healthcare-Associated Infections in NHS Hospitals in England. J Hosp Infect. 2014;86 Suppl 1:S1-70.
NICE. Infection: Prevention and control of healthcare-associated infections in primary and community care. CG139. 2012. London: National Institute for Health and Care Excellence; London.
Rickard CM, Marsh N, Webster J, et al. Securing All intraVenous devices Effectively in hospitalised patients—the SAVE trial: study protocol for a multicentre randomised controlled trial. BMJ Open. 2015;5(9):e008689.
Produced by the University of Southampton and Bazian on behalf of NIHR through the NIHR Dissemination Centre