This study examined the effect of introducing a 2% chlorhexidine gluconate and 70% isopropyl alcohol applicator (ChloraPrep) on blood culture contamination rates in the emergency department and two acute medical admissions units of a UK teaching hospital over one year. The monthly blood culture contamination rates decreased significantly from 7.5% prior to ChloraPrep introduction to 2.1% after its use, with the greatest decline in the emergency department. ChloraPrep significantly reduced the incidence of blood culture contamination and hospitals could benefit from lower contamination rates in meeting infection targets.

1. Reducing blood-culture contamination rates by the use of a
2% chlorhexidine solution applicator in acute admission units
Madeo M, Barlow G
Journal of Hospital Infection 2008; 69: 307-9
Background While blood culture is invaluable in the diagnosis of serious infection, contamination with
non-significant skin flora is relatively common and is associated with substantial healthcare costs
The consequences are not trivial. For example, patients may receive unnecessary antibiotics that
may in turn result in avoidable adverse effects such as Clostridium difficile-associated diarrhoea
(CDAD). Performance management targets for both MRSA bacteraemia and CDAD may be
inappropriately jeopardised
Thorough skin preparation is often neglected by medical staff and it is likely to be implicated in
many cases of blood culture contamination
Aim To examine the effect of introducing a 2% chlorhexidine gluconate in 70% isopropyl
alcohol applicator (ChloraPrep) on blood culture contamination rates in the
admission units of a 1500-bed UK teaching hospital
Methods The year-long study was performed in the accident and emergency department and
two acute medical admissions units of the hospital
The monthly total contamination rates were compared before and after introduction
of ChloraPrep by logistic regression analysis
Blood cultures were deemed contaminated if they grew coagulase-negative
staphylococci, diphtheroids, propionibacteria or micrococci
Results The ChloraPrep applicator significantly reduced the incidence of blood culture
contamination from 7.5% prior to its introduction to 2.1% (p<0.0001) in the four
months after implementation, excluding August as a ‘washout’ month
10
Prior to introduction of ChloraPrep Following introduction
Monthly blood culture of ChloraPrep
contamination rates in 8
the admissions units,
January to December 6
Washout
2007
(% cultures contaminated) 4
2
0
Odds ratio: 0.25 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
95% CI: 0.18-0.35; p<0.0001
n= 717 713 608 568 544 461 461 425 408 480 449 533

2. The observed decline was most marked in the A&E department
15
Blood culture A&E AMAU 1 AMAU 2
(unselected acute (acute respiratory,
contamination medical patients) infection and elderly
rates in each of the medicine)
admissions units 10
11.5%
(% cultures contaminated)
5
6.6%
3.9%
2.6%
1.7% 1.8%
0
Before introduction n= 1361 797 1545 577 1166 496
of ChloraPrep
Following the introduction
of ChloraPrep
Conclusion With the potential to significantly reduce blood culture contamination rates, hospital
trusts could find the ChloraPrep applicator useful in achieving their hospital-acquired
infection performance management targets
The cost of ChloraPrep is likely to be readily absorbed by savings associated with a
lower blood culture contamination rate
Prescribing Information contact with eyes, mucous membranes, middle ear and neural tissue. Should not be used in
ChloraPrep® (PL31760/0002) & ChloraPrep with Tint (PL31760-0001) 2% chlorhexidine children under 2 months of age. Solution is flammable. Do not use with ignition sources until
gluconate w/v / 70% isopropyl alcohol v/v cutaneous solution. Indication: Disinfection of dry, do not allow to pool, and remove soaked materials before use. Over-vigorous use on
skin prior to invasive medical procedures. Dosage & administration: ChloraPrep – 0.67ml, fragile or sensitive skin or repeated use may lead to local skin reactions. At the first sign of
1.5ml, 3ml, 10.5ml, 26ml; ChloraPrep with Tint – 3ml, 10.5ml, 26ml. Volume dependent on local skin reaction, application should be stopped. Per applicator costs (ex VAT) ChloraPrep
invasive procedure being undertaken. Applicator squeezed to break ampoule and release – 0.67ml (SEPP) - 30p; 1.5ml (FREPP) - 55p; 3ml - 85p; 10.5ml - £2.92; 26ml - £6.50.
antiseptic solution onto sponge. Solution applied by gently pressing sponge against skin and ChloraPrep with Tint – 3ml - 89p; 10.5ml - £3.07; 26ml - £6.83. Legal category: GSL.
moving back and forth for 30 seconds. The area covered should be allowed to air dry. Side Marketing Authorisation Holder: CareFusion UK 244 Ltd, 43 London Road, Reigate, Surrey
effects, precautions & contra-indications: Very rarely allergic or skin reactions reported RH2 9PW, UK. Date of preparation: July 2010.
with chlorhexidine, isopropyl alcohol and Sunset Yellow. Contra-indicated for patients with
known hypersensitivity to these constituents. For external use only on intact skin. Avoid CHL113a Date of preparation: August 2010