BETHESDA, MD. — The supply of weapons against multidrug-resistant gram-negative pathogens is running low, Henry M. Blumberg, M.D., said at an annual conference on antimicrobial resistance sponsored by the National Foundation for Infectious Diseases.
“We are struggling to treat these infections,” said Dr. Blumberg, professor of medicine at Emory University, Atlanta. “There's not a lot of information in the literature about controlling gram-negative pathogens. Most studies are about VRE [vancomycin-resistant enterococci] and MRSA [methicillin-resistant Staphylococcus aureus],” he explained.
Physicians at Grady Hospital in Atlanta, where Dr. Blumberg is an epidemiologist, have been unable to completely eradicate some forms of persistent multidrug-resistant (MDR) gram-negative bacteria, but they have developed strategies to reduce the risk of infections.
Here are seven strategies to help in the battle:
▸ Improve hand hygiene. Physicians are often the worst offenders and the ICU staff often has the poorest hand hygiene, Dr. Blumberg noted. Also, artificial fingernails have been associated with nosocomial infections and should not be worn by health care workers.
▸ Prevent nosocomial infections, especially pneumonia. Gram-negative pathogens are often the source of ICU infections.
▸ Use selective digestive tract decontamination. Use of intravenous prophylaxis for digestive tract decontamination has been shown to reduce the risk of bacterial infections during the early postoperative period. However, there have been reports of increased MRSA and VRE with this method.
▸ Reduce bloodstream infections. Techniques that have proved helpful include the use of maximum sterile barrier techniques; use of chlorhexidine on the skin prior to central line insertion also has been shown to reduce infection.
▸ Enhance environmental cleaning. A clean environment is important for the reduction and control of pathogens such as Acinetobacter baumannii, for which the environment might play a significant role in transmission.
▸ Improve nurse-to-patient staffing ratios. Data from previous studies have shown a relationship between increased resistance and fewer nursing hours per patient-day, but resistance decreased as staffing consistency improved.
▸ Improve antibiotic utilization. Potential methods to reduce inappropriate use of antibiotics include the application of practice guidelines, formulary restriction, and antibiotic cycling.
The staff at Grady Hospital conducted a self-study in which two groups of care teams were randomized either to an intervention designed to control for antibiotic resistance or to standard-of-care guidelines that had been developed by the hospital. In the intervention group, an antibiotic utilization team recommended an optimal therapy if the prescription was inappropriate based on hospital guidelines. The control group prescribed antibiotics without review by a utilization team.
Overall, the intervention group was deemed to have used antibiotics appropriately in 82% of cases, compared with 67% for the controls, Dr. Blumberg said.
“We can't eradicate these organisms, especially in surgery, but we are working to control them,” he said. “We need more studies to help us determine the best ways.”
Another management strategy, the “search-and-destroy” method of MDR infection management, involves active surveillance via frequent screening of patient cultures and contact isolation for anyone infected or colonized with MDR gram-negative bacteria. However, “what you screen for is based on what you are finding in your hospital,” he noted.
Although the search-and-destroy method may eradicate pathogens in some situations, it is almost impossible to do so in a surgical setting, he said.
Dr. Blumberg had no conflicts of interest to disclose.