Evaluation of Skin Antisepsis Prior to Blood Culture in Neonates

Review of Clinical Trials of Skin Antiseptic Agents Used to Reduce Blood Culture Contamination

False-positive blood culture results may lead to prolonged hospitalization, inappropriate antibiotic administration, and increased healthcare costs. We conducted a review of the literature to assess the effect of skin antiseptic agents on the rate of false-positive blood culture Results. We found no clear evidence to suggest which antiseptic should be used to prevent false-positive Results. Studies suggest, however, a possible benefit from the use of prepackaged skin antiseptic kits and alcohol-containing antiseptics.

Analyse critique de la littérature sur l’utilisation comparée de deux antiseptiques lors du cathétérisme vasculaire ou rachidien

OBJECTIVES

To analyze the most pertinent data from the literature concerning the use of an antiseptic solution before the elaboration of invasive procedures such as blood cultures, insertion of peripheral or central intravenous catheters, and arterial or epidural catheters, and to identify, if any, the "ideal" antiseptic or, at least, the most efficient.

DATA SOURCES

Review of the literature. Data collected from the Medline database concerning experimental, clinical and basic research studies published between 1966 and 2003 and a manual research of references of relevant papers.

RESULTS

After a brief historic and pharmacological reminder, the results of experimental and clinical studies are presented. Concerning the clinical studies, they concerned almost exclusively iodine products and chlorhexidine. These comparative studies are classified according to the punction site and the antiseptic solution used.

CONCLUSION

Even if the in vitro studies favor iodine products, chlorhexidine in alcoholic solution seems more efficient than povidone iodine in aqueous solution in the clinical setting. Several explanations are suggested to understand the in vitro/in vivo discordances. The place of povidone iodine in alcoholic solution, whose performances on the healthy skin are similar to those of alcoholic chlorhexidine, is being in evaluation.

A comparison of two versus one blood culture in the diagnosis and treatment of coagulase-negative staphylococcus in the neonatal intensive care unit

OBJECTIVES

This study compares two versus one blood culture in the diagnosis and treatment of coagulase-negative staphylococcus (CONS) in babies with suspected sepsis.

STUDY DESIGN

The study was performed at British Columbia's Children's Hospital Neonatal Intensive Care Unit between March 1999 to March 2000. One hundred pairs of cultures were drawn from two percutaneous sites from babies more than 48 hours old at the time of a sepsis screen. CONS cultured from both sites was regarded as evidence of infection. Positive culture from only one of the two sites was regarded as contaminant. The difference in rates of diagnosed CONS infection and reduction in antibiotic usage when using two versus one blood culture was calculated.

RESULTS

In 5% of babies, cultures from a second site did not substantiate the diagnosis of CONS when compared to the result from a single culture. The resultant reduction in antibiotic use was 8.2%.

CONCLUSIONS

Two blood cultures reduce the number of children diagnosed with CONS infection and reduce antibiotic usage.

Topical antibacterial agents

Topical antibacterial agents occupy an important niche of antimicrobial therapy for both inpatients and outpatients. These agents, including antiseptic and antibiotic preparations, are used for prophylaxis and treatment of infection. Prophylactic uses include application for traumatic and surgical wounds, burns, intravascular catheters, and eradication of S. aureus nasal carriage. Topical antibacterial agents are also used for treatment of primary and secondary pyodermas. Individual antibacterial agents have been reviewed. Of note, despite the widespread use of topical antibacterial agents, further data on which to guide therapy are needed in many instances.

Chlorhexidine compared with povidone-iodine as skin preparation before blood culture. A randomized, controlled trial

BACKGROUND

Chlorhexidine is better than povidone-iodine for care of catheter sites, but it is not known whether chlorhexidine is superior in reducing blood culture contamination.

OBJECTIVE

To determine whether alcoholic chlorhexidine is a more effective skin antiseptic for collection of blood cultures than aqueous povidone-iodine.

DESIGN

Randomized, controlled trial.

SETTING

Three adult intensive care units in a French university hospital.

PATIENTS

403 adults who had at least one blood culture drawn through a peripheral vein.

INTERVENTIONS

Patients were randomly assigned to receive skin preparation with an aqueous solution of 10% povidone-iodine or an alcoholic solution of 0.5% chlorhexidine before phlebotomy.

MEASUREMENTS

Contamination rates of blood cultures.

RESULTS

Of 2041 blood cultures collected in 403 patients, 124 yielded pathogens. Chlorhexidine reduced the incidence of blood culture contamination more than povidone-iodine (14 of 1019 cultures [1.4%] compared with 34 of 1022 cultures [3.3%]; odds ratio, 0.40 [95% CI, 0.21 to 0.75]; P = 0.004).

CONCLUSION

Skin preparation with alcoholic chlorhexidine is more efficacious than skin preparation with aqueous povidone-iodine in reducing contamination of blood cultures.

Prospective randomised trial of povidone-iodine, alcohol, and chlorhexidine for prevention of infection associated with central venous and arterial catheters

More than 90% of all intravascular device-related septicaemias are due to central venous or arterial catheters. To assess the efficacy of cutaneous antisepsis to prevent catheter-associated infection, we prospectively studied three antiseptics for disinfection of patients' central venous and arterial catheter insertion sites in a surgical intensive care unit. 668 catheters were randomised to 10% povidone-iodine, 70% alcohol, or 2% aqueous chlorhexidine disinfection of the site before insertion and for site care every other day thereafter. Chlorhexidine was associated with the lowest incidence of local catheter-related infection (2.3 per 100 catheters vs 7.1 and 9.3 for alcohol and povidone-iodine, respectively, p = 0.02) and catheter-related bacteraemia (0.5 vs 2.3 and 2.6). Of the 14 infusion-related bacteraemias (4 due to contaminated infusate or catheter hub, 10 due to infected catheters), 1 was in the chlorhexidine group and 13 were in the other two groups (odds ratio 0.16, p = 0.04). We conclude that use of 2% chlorhexidine, rather than 10% povidone-iodine or 70% alcohol, for cutaneous disinfection before insertion of an intravascular device and for post-insertion site care can substantially reduce the incidence of device-related infection.

Contamination of blood cultures during venepuncture: fact or myth?

Contamination of blood cultures is believed to occur mainly during the venepuncture procedure. Consequently, meticulous preparation of the venepuncture site is widely recommended. To determine whether the contamination rate is indeed affected by the quality of the antiseptic procedure at the venepuncture site, 181 paired cultures were collected from 176 patients during a 6-month period after either strict antiseptic cleansing of skin with alcohol followed by povidone-iodine, or after brief disinfection with alcohol alone. The contamination rate was not influenced by the antiseptic procedure, and corresponded to the accepted percentage reported in most other studies. Eight false positive cultures (4.4%) were obtained after strict antisepsis of the skin and 6 (3.3%) after short simple cleansing with alcohol (P = 0.39). Our results suggest that contamination of blood cultures may not be related to the venepuncture procedure--regardless of the antiseptic technique used--but may be due to later stages of laboratory handling and processing of the specimens. Review of the literature has provided further indirect evidence to support this conclusion.

Skin as a source of nosocomial infection: directions for future research

Whereas infections of the skin per se comprise only a fraction of all institutionally-acquired infections, the skin has become one of the most important reservoirs of nosocomial pathogens in the hospital. Professor Noble has provided a scholarly review of the increasing importance of the major constituents of the cutaneous microflora as nosocomial pathogens and what we know of their epidemiology. Unfortunately, the empiricism and limited scientific data which underlie essential infection control measures in this area, particularly in regard to cutaneous antisepsis and handwashing, is almost incongruous in an era in which controlled clinical trials have dominated most other areas of medicine. The numerous outbreaks traced to contaminated antiseptics and disinfectants over the past two decades, stand as mute testimony to the inadequate investigative attention this area has received.