Researchers explore the effect not adhering to the product guidelines has on the efficacy of CHG as a surgical antisepsis in patient prep.

February 17, 2010

Chlorhexidine gluconate (CHG) is often diluted prior to its use in surgical antisepsis and is applied in a one-scrub application. The manufacturer of this solution, however, does not advocate dilution of the product and recommends a two-scrub application. According to researchers at Mary Imogene Basset Hospital in Cooperstown, NY, no studies have previously examined the effect not adhering to the product guidelines has on the product’s efficacy.

In a pilot study performed with 60 volunteers, the researchers—Cecilia M. Loh MD, MPH, Tarun I. Bajaj MD and David C. Borgstrom MD, FACS—subjects were randomly assigned to a control group or to one of five treatments. Control subject received normal saline alone. Treatment subject received two-percent CHG diluted by concentrations of normal saline from 0 to 80 percent.

All the subject had one foot scrubbed with their given concentration in a two-scrub application. After this, baseline and postprep swabs were collected and incubated, and the researchers measured bacterial colonies after 48 hours.

In the second part of the study, all the subjects in the study received 50 percent CHG preparation and colony counts were measured after one-scrub and two-scrub applications.

The researchers found that subjects had greater than 500 bacterial colonies at baseline. After a two-scrub prep in the first part of the study, median colony counts decreased by 100 percent for subjects in the treatment group, and by 80 percent for subjects in the control group. A few treatment subjects had a 97-99 percent colony reduction, the researchers reported.

In the second part of the study, mean colony counts decreased by 98.8 percent after one scrub and by 100 percent after two scrubs.

What this means for patient preparation
The researchers concluded that CHG is equally effective in eradicating skin bacteria over a wide range of concentrations. A two-scrube application appears to be superior to one-scrub.

Source: Journal of the American College of Surgeons