Surveillance of antibiotic resistance in ICUs in southeastern Sweden. ICU Study Group of the South East of Sweden

Abstract

Background: A study was designed to assess a computer-based program for continuous registration of antibiotic resistance, statistics concerning severity of illness, and consumption of antibacterial drugs.

Methods: The frequency of antibiotic resistance among bacteria in eight ICUs in southeastern Sweden was investigated yearly from 1995 through 1997. The antibiotic consumption in the ICUs was registered as defined daily doses (DDD) and compared to severity of illness (APACHE-II scores).

Results: There was a statistically significant increase in ampicillin resistance among Enterococcus spp. between 1996 and 1997, which was due to a shift from Enterococcus faecalis to Enterococcus faecium. A high prevalence of resistance among coagulase-negative staphylococci to oxacillin (approximately 70%), ciprofloxacin (approximately 50%), fucidic acid (approximately 50%) and netilmicin (approximately 30%) was seen in all ICUs during the whole study period. There was a statistically significant increase in ciprofloxacin resistance among Escherichia coli and Enterococcus spp. The resistance among Enterobacter spp. to cefotaxime decreased but this change was not statistically significant. Efforts were made to avoid betalactam antibiotics, except carbapenems, for treatment of infections caused by Enterobacter spp. and the consumption of cephalosporins decreased whereas the consumption of carbapenems increased. The total antibiotic consumption decreased by 2.5% during the study period. There was no correlation between APACHE II scores and antibiotic consumption.

Conclusions: Each ICU within a hospital ought to have a program for "on-line" antibiotic resistance surveillance of drugs used in that unit so that changes in empirical treatment can be made when there is an increase in antibiotic-resistant isolates within that unit.