Should We Cut Back on Chlorhexidine Bathing?

Skin is the body’s largest organ, as adults carry roughly 8 pounds and 22 square feet of it around. Unfortunately, this impressive organ is also a gateway for germs to enter our body. Abrasions and invasive devices that penetrate the skin provide microorganisms with a prime way to enter the body and cause infections. This issue is of particular concern for patients who are in the hospital with a higher risk for health care-associated infections and bloodstream infections related to medical devices. Beyond medical devices, how can we go about reducing the bioburden on skin to avoid infections? Skin and nasal decolonization, for example, has long been a strategy used by hospitals to help reduce infections.

From there, the question becomes: What is the best strategy for universal decolonization of the skin? Is it routine bathing or chlorhexidine? Investigators recently asked this question to help prevent multidrug-resistant organisms and all-cause bloodstream infections across 53 hospitals. The study, which was published in the journal The Lancet, was led by Susan Huang, MD, who worked with colleagues to evaluate the use of chlorhexidine (CHG) bathing in non-critical-care units through the ABATE Infection (Active Bathing to Eliminate Infection) trial.

The ABATE Infection trial used data from 53 hospitals to study patients within a 12-month baseline period (March 2013 to the end of February 2014), a 2-month phase-in period, and then a 21-month intervention period from 2014 to 2016. Non-critical-care units were used to evaluate the difference between these 2 cleaning strategies on a daily basis. The investigators also used mupirocin for those with established methicillin-resistant Staphylococcus aureus (MRSA) infections (both in clinical cultures and all-pathogen bloodstream infections).

Outcomes of cultured MRSA or vancomycin-resistant enterococcus (VRE) were measured as “in the unadjusted, intention-to-treat population as the HR for the intervention period versus the baseline period in the decolonization group versus the HR in the routine care group. Proportional hazards models assessed differences in outcome reductions across groups, accounting for clustering within hospitals.”

The study included data on 339,902 patients in total. Available information indicates that 156,889 patients were in the routine care group and 183,013 were in the decolonization group (ie, those receiving CHG bathing daily). The non-critical-care units followed the decolonization procedure and used a 4% rinse-off liquid CHG in the shower and a 2% leave-on CHG disposable cloth for bed baths. Hospital personnel, including the infection prevention team and unit managers, were responsible for implementing this protocol within each hospital.

Those in the decolonization group were given educational material for staff and patients, as well as training. Although the primary outcome was assessing those found to have MRSA or VRE in clinical cultures, the investigators noted that secondary outcomes were assessed for an additional study (not listed within this publication) for urinary tract infections, blood culture contaminations, and Clostridium difficile infections.

The investigators observed that those in the decolonization group utilizing CHG bathing tended to use bed baths versus showers (78%) and had a median compliance of 88% if mupirocin was indicated. When assessing the primary outcome, they found that the hazard ratio for the intervention period versus the baseline period was 0.79 within the decolonization group, while it was 0.87 in the routine care group. The difference in hazard ratios was not statistically significant and there were 25 adverse events involving the use of CHG (ranging from rash to pruritis). However, the investigators did find in their post hoc subgroup analyses that for those patients with medical devices (central venous catheters, midline catheters, and lumbar drains), there was a greater reduction of MRSA or VRE with the decolonization protocol versus the daily cleaning routine.

Overall, the investigators note that although CHG bathing has been widely accepted as a method for decolonization, with or without nasal decolonization, the ABATE Infection trial showed no statistically significant reduction in clinical cultures between CHG bathing and routine care.

The investigators did note that there was a significant improvement over baseline values for primary outcomes in both groups. However, the lack of significant reduction in MRSA and VRE in clinical cultures or bloodstream infections in oncology units alone does imply that there is a significant need to re-evaluate the efficacy of CHG bathing and our dependence on it. CHG clearly has a role in prevention of device-associated infections however, more research is needed to address its empiric use in those patients without such devices.