Hand gel fails to curb infections on its own

Gel must be used in conjunction with other measures

While hand washing is strongly emphasized as a patient safety strategy, a new study published in the January 2008 issue of Infection Control and Hospital Epidemiology1 indicates that hand washing alone may not be enough to ensure lower infection rates.

The study, conducted at Nebraska Medical Center in Omaha, examined the effectiveness of alcohol-based hand gels — thought to be more effective than soap and water. The findings were based on 300 hours of hand hygiene observations of nurses and doctors in two comparable intensive care units over a two-year period.

The researchers placed gel dispensers in the units, and every two months bacteria samples were taken from health workers' hands. Usage increased — from 37% to 68% in one unit and from 38% to 69% in the other. However, they found "no significant relationship" between rates of hand gel use and infections among patients. "Quite frankly, [the results were] a little bit disappointing," admits lead author Mark Rupp, MD, professor of infectious disease at the University of Nebraska Medical Center and medical director of the health care department of epidemiology. "But the take-home message is that hand hygiene is not a panacea; there is not a single cure for all infection control problems."

Looking at compliance

The initial purpose of the study, Rupp continues, was to examine not only infection rates, but also staff compliance with the use of hand gel. "We performed a prospective, controlled study over a two-year period of time in these ICUs in which we were trying to ascertain whether the use of alcohol-based hand hygiene gel resulted in increased [hand washing] compliance and if it correlated with improved outcomes," he says. "Hand hygiene compliance rose dramatically in relation to when the gel was present in the unit, but unfortunately we saw no correlation with changes in the infection rate."

There was media commentary following the release of the study positing that Rupp's findings contradict the Centers for Prevention and Control (CDC) guidelines for hand washing, but he disagrees. "Some people interpreted [the results] wrongly and said hand hygiene was not effective and the CDC recommendations are incorrect, but what I think the bottom line is, is that the pathogenesis of nosocomial infection is complex — and no single intervention like hand hygiene will have a dramatic effect. In other words, hand hygiene is one ingredient in an overall recipe of infection control."

Other 'ingredients'

So, what are some other "ingredients" for Rupp's recipe? "You should pay attention to how you take care of urinary catheters," he advises. "Have ventilator patients positioned correctly and provide proper mouth care known to prevent ventilator-associated pneumonia, and use antibiotics prudently to avoid selective pressure for antibiotic-resistant pathogens. If you do all of these, along with maintaining a good, clean environment, then you will get a big impact."

There were some other findings of the research that were quite interesting, Rupp continues. "Every two months we cultured the nurses' hands and correlated what we found [in terms of microbial infestation] with other factors, like the length of fingernails and wearing rings," he relates. "Any length of fingernail over two millimeters in length was associated with increased carriage of microorganisms. Likewise, if you were wearing rings it was associated with increased numbers of microbes on the hands."

In terms of the findings concerning overall rates of infection, the authors did point out in the paper, says Rupp, that the research was "statistically underpowered" to find a small impact on the infection rate. "The rates were so low to begin with that it would be difficult to show a statistically significant impact," he notes. "That's why we designed it to be over a two-year time period; we hoped [the gel] would have a dramatic effect and we would see those changes."

Would things have been different if the compliance rate had been even higher — say 90%? "That's a great point; it may be that compliance was not high enough to give this hand hygiene maximal benefit," he responds. "Or, it could depend on the virulence of the organism underlying host immunity."

The bottom line, he concludes, is that the study should be viewed as "a cautionary tale."

Reference

  1. Rupp ME, Fitzgerald T, Puumala S, Anderson JR, et. al. Prospective, Controlled, Cross-Over Trial of Alcohol-Based Hand Gel in Critical Care Units. Infect Control Hosp Epidemiol 2008; 29:8-15.

[For more information, contact:

Mark Rupp, MD, professor of infectious disease, University of Nebraska Medical Center, medical director of the health care department of Epidemiology. E-mail: merupp@unmc.edu.]