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Efficacy of Chlorhexidine-Containing Cutaneous Antiseptics in Prevention of (Vascular) Catheter Related Infection. 

Andrew Longmate on behalf of the SICS EBM group 

Intensive Care Unit, Stirling Royal Infirmary, Livilands,  Stirling FK8 2AU

Correspondence: Andrew.Longmate@fvah.scot.nhs.uk

Citation: EBM Reviews. Scottish Intensive Care Society EBM Group. Andrew Longmate. Efficacy of Chlorhexidine-Containing Cutaneous Antiseptics in Prevention of (Vascular) Catheter Related Infection. 2005

Background: (Vascular) Catheter related bloodstream infection is associated with an increased morbidity, mortality, length of hospitalization and medical costs. The pathophysiology of catheter related infection  remains uncertain but three main possibilities have been identified. These include skin colonisation and invasion of the transcutaneous insertion tract by micro-organisms of the patient ‘s own flora, hub colonisation with contiguous intraluminal spread or infusate contamination. Heavy cutaneous colonisation is a risk factor for CVC related BSI and chlorhexidine is a potent germicide that has been used for many years for skin disinfection. Multimodal strategies are important in the prevention of intensive care associated infections including catheter related blood stream infections. However Chlorhexidine containing cutaneous antiseptics have been widely recommended for use prior to catheter insertion to prevent CrBSI. 

Objectives: The objectives of this search was to assess published RCTs and meta-analyses that have attempted to address whether the use of chlorhexidine skin preparation may be beneficial in preventing catheter related bloodstream infection.

Search strategy: Medline(1) catheterisation (explode) (2) catheterisation/ or catheterization, Swan-Ganz/ or Heart Catheterization/ or ctaheterisation.mp or Catheterization, Central venous (3) 1 and 2 (4)infection or infection m.p. (5) 3 and 4 (6) limit 5 to English language and "all adult(19 plus years)" and meta analysis. (7) limit 5 to "all adult(19 plus years)" and randomised controlled trial (8) 6 or 7. This resulted in 21 publications. Additional hand searches of reference lists from these publications and review articles. 

Selection criteria: RCTs or meta-analysis published in peer reviewed journals comparing rates of catheter colonization or infection between different antiseptic skin regimes prior to insertion of vascular catheter (arterial or central venous catheter).

Excluded tunnelled catheters, antimicrobial impregnated catheters, non adult patients and non ITU patients, insertion site infections and articles not published in English language. Studies presented at meetings or in abstract form were also excluded. 

Definitions: Definitions used vary between different studies which  can make comparisons confusing. For the purposes of this review the results have been limited to 2 main groups: catheter colonization and bacteraemic catheter related blood stream infection.  

1. Colonisation:  is clearly a surrogate marker which fits with one potential mechanism of infection which assumes that catheter colonisation is a key step to catheter related blood stream infection. It may not have direct clinical implications. The 3  main ways to define colonisation include

•      Qualitative: isolation of organism from catheter tip.

•      Semiquantative: Greater or equal to 15 colony forming units (by roll plate technique)

•      Quantitative estimation: greater than 10 ³ bacteria

2. Bacteraemic Catheter Related Blood Stream Infection: can be defined as bacteraemia (or fungaemia) in a patient with an intravascular catheter with at least one positive blood culture obtained from a peripheral vein , clinical manifestations of infection (ie fever, chills and/or hypotension) and no apparent source of BSI except the catheter. One of the following should be present: a positive semiquantitative (>15cfu/catheter segment) or quantitative (>10³ cfu/catheter segment cartheter) culture whereby the same organism  (species and antibiogram) is isolated from the catheter segment and the peripheral blood.  (from CDC definition)

Search results: Produce 5 papers – Four  RCTs^1-4, one meta-analysis⁵.

Analysis of the Evidence:

1. Colonisation (Data was analysed by CATmaker^TM software)

• 2 Trials showed a significant reduction in colonisation using chlorhexidine compared to povidone iodine(1,2).
• 2 Trials showed no significant difference (3,4). One study was not adequately powered to detect a difference(3) and the other (4) showed a trend towards reduction.
• 1 Trial Showed that combination iodine/chlorhexidine better than either alone for prevention of colonisation (4).

* Apparently shows significant reduction.  Not verified by authors.

2. Catheter Related Bacteraemic Blood Stream Infection (BSI)

• The definition used for purposes of this review includes isolation of the same organism from the catheter tip and peripheral blood culture.

• One trial showed a benefit for one definition of catheter related blood stream infection. (2). However their definition was non standard and did not require positive blood culture of the same organism from a peripheral vein as was isolated from the catheter tip segment. They were unable to show any difference for bacteraemic CrBSI. One trial did not look at bacteraemic infection as an end point. (4)

• The other 2 studies failed to show a statistically significant difference in catheter related bloodstream infection. (bacteraemic catheter related blood stream infection).