Review
Skin antiseptics in venous puncture-site disinfection for prevention of blood culture contamination: systematic review with meta-analysis

https://doi.org/10.1016/j.jhin.2010.10.015Get rights and content

Summary

Blood cultures drawn by venous puncture are common clinical procedures for the detection of bacteraemia. Blood culture contamination (BCC) can lead to clinical misinterpretation and unnecessary expenses. We aimed to systematically review randomised controlled trials (RCTs) with skin antiseptics for prevention of contamination in venous-puncture drawn blood cultures. We conducted database search using CENTRAL (Cochrane Library issue April 2010), MEDLINE, EMBASE and mRCT, in June 2010. All RCTs testing skin antiseptics in venous-puncture drawn blood cultures were retrieved. Relative risk (RR) of the BCC outcome was analysed by random effects method using confidence interval (CI) of 95%. Studies were assessed by one review author and checked by another. Six studies were identified. Single-trial comparisons showed that alcoholic iodine tincture was better than non-alcoholic povidone-iodine, and isopropyl/acetone/povidone-iodine showed superiority against isopropyl/povidone-iodine. Meta-analysis demonstrated that alcoholic chlorhexidine was better than non-alcoholic povidone-iodine (RR: 0.33; 95% CI: 0.24–0.46) in 4757 blood cultures from two trials. Alcoholic solutions were better than non-alcoholic products (0.53; 0.31–0.90) in 21 300 blood cultures from four studies. Two trials with 13 418 blood cultures showed that iodine tincture was not superior to povidone-iodine in BCC prevention (0.79; 0.54–1.18). Alcoholic iodine was not different from non-alcoholic iodine (0.79; 0.53–1.17). Comparison of chlorhexidine vs iodine compounds was not conclusive. Alcohol alone was not inferior to iodinated products for prevention of contamination in venous-puncture drawn blood cultures. The association of alcohol and povidone-iodine did not seem to be useful. Alcoholic chlorhexidine solutions reduced blood culture false positives compared with aqueous povidone-iodine.

Introduction

Venous punctures are common hospital procedures and they can be used to collect blood for microbiological culture. Blood cultures are essential to detect bacteraemia and they are useful for therapeutic decisions. However, a false-positive blood culture due to contamination (BCC) by micro-organisms from places other than blood is a challenging problem for the physician as it can lead to misinterpretation and inappropriate treatment. It can contribute to considerable financial expenses, since additional tests can be done and unnecessary or inadequate antibiotics are likely to be administered.1, 2, 3 The dimension of the problem is not well determined since it can range from 0.6% to 6%.4 Micro-organisms that contaminate cultures can come from patient skin, healthcare personnel skin, contaminated recipients, or laboratory procedures. Patients’ skin disinfection decreases the number of blood culture false positives. Alcohol, chlorhexidine and iodine products are commonly used for this purpose.

The aim of this meta-analysis was to determine which skin antiseptic is the best to decrease blood culture contaminations.

Section snippets

Searching

A searching strategy was developed using CENTRAL (Cochrane Library issue April 2010), MEDLINE, EMBASE and mRCT databases without language limitations, in June 2010.

Search was made using a filter for randomised controlled trials (RCTs) with the following keywords: ‘antiseptic’, ‘chlorhexidine’, ‘iodine’, ‘povidone’, ‘alcohol’, ‘skin’ and ‘blood culture’. Boolean operators AND and OR were used to combine the terms. NOT operator was used to exclude surgical studies and catheter disinfection trials.

Results

Applied search filters resulted in 40 references identified initially in the four databases. Fourteen duplicated records were removed resulting in 26 studies. After title and abstract evaluation, 17 studies were excluded because they did not analyse skin antiseptics and/or blood culture contamination. The remaining nine studies were evaluated for possible inclusion in meta-analysis. Three trials were excluded after full-text assessment because they did not test skin antiseptics for prevention

Discussion

Our systematic review analyses a long-debated issue: which skin antiseptic is superior in terms of fewer false-positive cultures?

There were some differences in the definition of blood culture contamination between studies (Table I). In future clinical trials in this area, investigators should take into account a single definition of BCC, as the Q-Tracks cohort study did for 356 clinical laboratories.12

Twenty percent of skin bacteria are in the deeper layers, untouched by antiseptics.13 Blood

Conclusions

Alcohol is not inferior to iodinated solutions. The association of alcohol and povidone-iodine does not seem to be useful. The association of alcohol with iodine tincture is more likely to be useful.

Alcoholic chlorhexidine solutions showed statistically significant reduction in blood culture false-positives compared with aqueous povidone-iodine, and a non-significant but potentially clinically relevant reduction of outcome compared with alcoholic iodine.

Overall, alcoholic products appear to be

Conflict of interest statement

None declared.

Funding sources

None.

References (27)

  • R.B. Schifman et al.

    The effect of skin disinfection materials on reducing blood culture contamination

    Am J Clin Pathol

    (1993)
  • L.G. Bekeris et al.

    Trends in blood culture contamination: a College of American Pathologists Q-Tracks study of 356 institutions

    Arch Pathol Lab Med

    (2005)
  • S. Selwyn et al.

    Skin bacteria and skin disinfection reconsidered

    Br Med J

    (1972)
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