Chlorhexidine: The “Preferred” Skin Antiseptic
In August 2002, the Centers for Disease Control and Prevention (CDC) issued the following Category IA recommendation (CDC Morbidity and Mortality Weekly Report, Aug. 9, 2002/Vol.51/No.RR-10): With respect to catheter site care, “Disinfect clean skin with appropriate antiseptic before insertion and at time of dressing change ... 2 percent chlorhexidine is preferred.” The recommendation also notes that, as of that time, “use of a chlorhexidine sponge” for insertion site care was an unresolved issue. Readers of this issue and the January 2005 issue of ICT will note that infectious disease expert Dennis Maki, MD, has spoken highly of both these products with respect to their abilities to prevent catheterrelated bloodstream infections (CRBSIs). The following interview with noted expert Marcia Ryder, PhD, RN, explores in some detail the use of two chlorhexidine-containing products, ChloraPrep™ (Medi-Flex) and Biopatch™ (Ethicon, Inc, Johnson & Johnson), and answers many commonly asked questions about these two infection control devices.
ICT: What is ChloraPrep?
MR: ChloraPrep is a solution containing 2 percent chlorhexidine gluconate and 70 percent isopropyl alcohol. It comes in various applicators that vary in size and surface configuration. Note that it is not an aqueous solution and should not be used where the use of isopropyl alcohol is prohibited.
ICT: How long has chlorhexidine been used in clinical practice?
In Europe and other markets outside of the United States, chlorhexidine (in varying concentrations) has been used for over 20 years. Even in the U.S., chlorhexidine — in the form of Hibiclens™ — has been in common use for more than a decade.
ICT: What are the advantages of ChloraPrep as a skin antiseptic?
Chloraprep works through a dual mode of action, both denaturing microbial proteins and disrupting cell membranes. It has a rapid onset of bactericidal action and prolonged antimicrobial efficacy—immediate and residual effects. ChloraPrep has demonstrated superior efficacy to aqueous chlorhexidine in reducing bacterial counts immediately and at 24 hours. ChloraPrep has also demonstrated superiority to isopropyl alcohol in maintaining reduced colony-forming units on the skin over a five-day test period. In addition, the results of a recent meta-analysis (Chalyakunapruk N, et al. Ann Intern Med. 2002;136,792) suggest that the incidence of bloodstream infections is significantly reduced in patients with central vascular catheters who receive chlorhexidine gluconate vs. povidone-iodine for insertion site disinfection.
ICT: Are there any special usage instructions for ChloraPrep?
Yes. First, attention must be given to the CDC recommendation of applying an antiseptic to clean skin for both preoperative skin preparation as well as catheter insertion site care. Recommendations for skin cleansing prior to catheter insertion may be found in the Association of periOperative Registered Nurses (AORN) Recommended Practices for Skin Preparation. Mechanical removal of dirt, dead skin cells and surface bacteria increases the effectiveness of the antiseptic. The commonly taught triple alcohol and/or triple iodophor, circumferential, inside-out technique of skin preparation for insertion site care, while theoretically sensible, is not an evidenced based practice. Transient bacteria reside on the surface of the skin while resident bacteria exist on the surface, hair follicles, and within at least the first five layers of the epidermal cells. The objective of skin antisepsis is to remove as many of these as possible. A mechanical, side-to-side, friction prep may be more effective in reducing the bacterial burden prior to puncture of the skin and subsequently under the dressing. The circular technique may be used on the last application to remove any remaining bacteria away from the insertion site. It may be noted that the manufacturer used the side-to-side technique in the Phase III efficacy studies submitted to the FDA for marketing approval. Clinicians should not remove ChloraPrep with sterile water, saline, or alcohol. Instead, it should be allowed to dry thoroughly to maximize effectiveness and prevent skin irritation.
ICT: What about cost? Surely ChloraPrep costs more than isopropyl alcohol or povidone iodine swabsticks.
True. But the cost to treat a single CRBSI is roughly $29,000. Preventing just one such infection more than covers the annual cost differential. A recent study of the clinical and economic benefits of chlorhexidine compared to povidone iodine (Chaiyakunapruk, et al. CID. 2003:37,764) found that the use of chlorhexidine gluconate for vascular catheter insertion site care reduced the CRBSI rate by half. Results in this same study estimated an expected cost savings of $113 for each CVC used and $8 for each peripheral catheter used. Another aspect to consider is the potential for litigation when failure to comply with guidelines and standards results in adverse patient outcomes. Failure to use chlorhexidine, which the CDC clearly states, “is preferred,” may open a facility to other costly liabilities should an “avoidable” CRBSI occur.
ICT: Let’s talk about another chlorhexidine-containing product, Biopatch. What is it and does it work?
Biopatch is a foam disc impregnated with chlorhexidine gluconate and slit so that it may be applied around a catheter at the insertion/ exit site. Its antimicrobial action has been shown in in vitro testing to extend up to an inch beyond the margin of the disc itself and to last for up to seven days. There are current published data showing that in both pediatric and adult populations and for a variety of different catheters (e.g., PICCs, CVCs, arterial and epidural catheters), Biopatch is effective in reducing CRBSIs and site infection. For example, Maki has recently presented his data from a randomized, investigator-blinded trial that Biopatch reduced CRBSIs by 60 percent and local infection by 44 percent in short-term CVCs and arterial catheters.
ICT: Why is use of the chlorhexidine sponge an unresolved issue with the CDC?
The CDC guidelines are the result of the work of experts in the field who examine existing evidence and opinion to achieve consensus on recommendations for practice. Some of the data on Biopatch is new and compelling but was not available to the committee at the time of their deliberation on the 2002 guidelines. With the demand for improved outcomes in the reduction of healthcare-acquired infections, I suggest that clinicians actively examine the existing data to drive decisions for change in practice.
ICT: What about cost? If we are already using ChloraPrep, can we really be expected to add more cost by using Biopatch, too?
MR: Remember, the cost of treating a CRBSI is about $29,000. Preventing just one such infection more than pays the annual bill for Biopatch. Also remember that JCAHO considers a death from a CRBSI to be a sentinel event and that reduction of CRBSIs is one of JCAHO’s and the CDC’s target outcomes for 2005. These considerations, plus the fact that for very little cost, patient morbidity and mortality can be reduced, making cost a non-issue in the use of the chlorhexidine sponge.