Focused microbiologic surveillance by specific hospital unit: practical application and clinical utility.

Focused microbiologic surveillance by specific hospital intensive care units (ICUs) revealed important differences in the occurrence of pathogens among units and at different times. Moreover, there were striking differences between the antibiogram summaries from certain ICUs and those from the hospital as a whole. Accordingly, an ongoing focused microbiologic surveillance was conducted for hospital ICUs to define unit-specific problems more clearly. To apply these data practically, results of focused surveillance were given to the ICU medical directors. The directors were able to institute unit-specific modifications of antimicrobial usage based upon the prevalent pathogens and their susceptibility patterns within each unit. After 1 year of this approach, the susceptibility patterns of Pseudomonas aeruginosa to imipenem and other antipseudomonal beta-lactam agents were improved in a number of ICUs that had previously noted resistance problems of several years' duration. Susceptibility of P aeruginosa was markedly improved in the medical ICU. The susceptibility patterns of Enterobacter cloacae were less affected, if at all. A review of antimicrobial use revealed that the use of most antipseudomonal agents in the medical ICU had decreased by approximately 50% or more. It is concluded that modification of antimicrobial use in ICUs based on focused microbiologic surveillance is a promising way to detect and minimize problems with resistance.