BETHESDA, MD. The antimicrobial stewardship program at the health sciences center of West Virginia University, Morgantown, has been successful in reducing resistance in some pathogens, while generating more questions about others, according to Dr. Arif R. Sarwari, the program's director.
In its first 5 years, the program at the tertiary care teaching hospital principally used prospective auditing methods and protocols for antibiotic cycling, coupled with educational strategies, to reduce the use of specific antibiotics and, in some instances, see a drop in rates of resistance.
Such results may not have been possible without the support and involvement of administrators and clinicians from different specialties, many of whom are members of the university's Antimicrobial Review Subcommittee and participated in the creation of the program. Cooperation is necessary because the interventions needed in various departments may differ and may cross a variety of disciplines, Dr. Sarwari said at an annual conference on antimicrobial resistance sponsored by the National Foundation for Infectious Diseases.
The antimicrobial stewardship program began in 2003 and follows many of the recommendations formulated in guidelines issued by the Infectious Diseases Society of America and the Society for Healthcare Epidemiology of America (Clin. Infect. Dis. 2007;44:15977), said Dr. Sarwari, who is a member of the committee.
It is unclear which combinations of modalities for reducing antimicrobial resistance work best, and "until I have 15 different institutions using 15 different combinations and putting their results out there, how do I know which one works and which one doesn't? This was our attempt to put out what we think is a sensible approach," Dr. Sarwari said in an interview.
Although many hospitals have programs to monitor and reduce antimicrobial resistance, most simply restrict the use of certain agents by having one person who approves or denies their use. But West Virginia University prospectively audits antimicrobial use and resistance every 6 months, and implements changes through educational interventions.
This helps to avoid an "us versus them" phenomenon and should help to sustain the program over the long term, Dr. Sarwari said. "Unless you have a buy-in from the end users, this will not work."
Although it was relatively simple to decide to define antimicrobial use through the measurement of defined daily doses per 1,000 patient-days, it took about 6 months of effort to convert data that are captured for billing purposes into data that can be used longitudinally, he said. To inform hospital administrators, the program also tracked the proportion of the pharmacy budget spent on antimicrobial drugs.
Educational programs were established to encourage or discourage the use of select antimicrobial agents, while strategies to promote the use of alcohol-based hand sanitizers were put in place. In addition, the committee made a pocket-card guide available on an educational Web site. The card featured choices of antimicrobials for various clinical scenarios, listed the susceptible proportion of microorganisms that had been identified for that particular year, and gave the top three choices of antimicrobial agents for a particular pathogen (as perceived by the institution). It also noted if a pathogen had shown a 10% or greater rise in resistance to particular drugs during the past year.
Interventions centered on the principle of cycling the selection of antimicrobial drugs based on local surveillance of resistance rates, and were tailored for different units of the hospital. For example, with help from ICU intensivists, the committee developed a ventilator-assisted pneumonia protocol that incorporated a strategy of de-escalating antibiotic therapy from broader to more specific pathogen coverage, and the bone marrow transplant unit created a febrile neutropenia protocol.
The committee members decided not to keep a very restricted formulary except for quinolones, because more than half of the Pseudomonas strains in the ICU were resistant to ciprofloxacin, Dr. Sarwari said.
During the first 5 years of the stewardship program (20032007), the number of defined daily doses per 1,000 patient-days of quinolones declined by 81%; the same defined measure of ceftazidime declined by 37%, he said. The committee saw a concomitant rise in the use of agents that were designated to replace quinolones and ceftazidime (aminoglycosides and cefepime, respectively). At the same time, the antimicrobial drug proportion of the pharmacy procurement budget declined from 16% to 8%.
Changes in drug resistance during the period yielded "mixed results," Dr. Sarwari said. During 20042006, rates of ciprofloxacin resistance for Pseudomonas declined from 38% to 22% and for Acinetobacter from 25% to 0%. In 2007, these rates rose again to 34% and 16%, respectively. In the same time period, resistance to ciprofloxacin gradually increased in Escherichia coli from 7% to 20%. Klebsiella resistance to ceftazidime remained stable at about 5%.