Study Explores Chlorhexidine Bathing in ICUs

Vanderbilt University Medical Center researchers have found that bathing critically ill patients with disposable chlorhexidine cloths did not decrease the incidence of healthcare-associated infections when compared to less expensive nonantimicrobial cloths, according to a study that appeared online in JAMA last week. The study was released to coincide with its presentation at the Society of Critical Care Medicine's 44th Critical Care Congress in Phoenix.

"Infections overall are the No. 1 complication in hospitals, superseding everything else. Critically ill patients, those admitted to the intensive care unit, have multiple reasons why they are the most vulnerable population," says first author, Michael Noto, MD, PhD, a clinical fellow in pulmonary and critical care medicine. "They tend to have venous access devices and urinary bladder catheters that are conduits for bacteria to get in and cause infection. They are also critically ill and relatively immune-suppressed."

Infections increase costs, rates of death, length of hospital stay and make patients sicker, he adds.

Bacteria that live on the skin normally can become pathogenic during a hospital stay and gain access to the body and cause infections. So, bathing patients with pre-moistened cloths designed to kill the bacteria living on the skin is thought to decrease the incidence of infections.

Bathing patients with 2 percent chlorhexidine, a broad-spectrum topical antimicrobial agent, is incorporated into some expert guidelines, but previous studies suggesting it was better at preventing infections were not well supported, says Arthur Wheeler, MD, professor of medicine.

"This is a practice that is going on all across in the country, not at every single hospital, but at many hospitals; it's reasonably expensive," says Wheeler. "The scientific evidence that chlorhexidine cloths make a difference was weak."

During the course of the study, nurses and care partners bathed 9,340 patients in Vanderbilt's five adult intensive care units for a 10-week period followed by a two-week washout period (a period allowed in order to eliminate the effect of the first intervention before starting a new intervention), during which patients were bathed with nonantimicrobial disposable cloths, before switching to the alternate bathing treatment for another 10 weeks. Each unit crossed over between bathing assignments three times during the study.

A total of 55 infections occurred during the chlorhexidine bathing period (4 central line-associated bloodstream infections [CLABSIs], 21 catheter-associated urinary tract infections [CAUTIs], 17 ventilator-associated pneumonia [VAP], and 13 Clostridium difficile) and 60 infections during the control bathing periods (4 CLABSI, 32 CAUTI, 8 VAP, and 16 C difficile infections).

There was no significant difference between groups in the rate of health care-associated infections, even after adjusting for various factors. Other infection-related secondary outcomes, including health care-associated bloodstream infections, blood culture contamination, and clinical cultures positive for multi-drug resistant organisms were also not improved by chlorhexidine.

The research team utilized Vanderbilt's electronic medical records for data analysis.

"This is a great example of learning from our own data...and it has a lot of features of what Vanderbilt is most excited about - translational research using the electronic medical records," says Dan Byrne, director of quality improvement and program evaluation, Department of Biostatistics.

"This important investigative work was partially supported by the Vanderbilt Institute for Clinical and Translational Research (VICTR) and is a prime example of how translational research can reach far into hospital and clinical operations to the benefit of all. Ideally, this accomplishment can help pave the way to the development of an optimal, continually learning healthcare system at Vanderbilt," says Gordon Bernard, MD, professor of medicine and associate vice chancellor for research.

Chlorhexidine's use in hospitals extends beyond infection control -- primarily to prep a patient prior to surgery.

"I don't think our results should be over-interpreted as to say chlorhexidine has no benefit in any setting at any time, but I think it's fair to say in the largest study done to date that included every kind of ICU, except a burn ICU, we couldn't find a benefit on infections," Wheeler says.

The additional study authors include Bernard, Wheeler, Byrne, Henry Domenico, MS, Tom Talbot, MD, MPH, and Todd Rice, MD, MSc.

Source: Vanderbilt University Medical Center

For a counterpoint to this study, CLICK HERE.