Use of Microbiologic Findings to Manage Antimicrobials in the Intensive Care Unit

Abstract

As part of a wider antimicrobial management programme implemented since 2003 at the Bolzano Central Hospital, Italy, an interdisciplinary, interventional programme was performed in the general intensive care unit (ICU). The aims of the antimicrobial management programme were to improve antimicrobial use and reduce drug resistance. The results showed that the implementation of the antimicrobial management programme through microbiological surveillance and a pharmacokinetic-driven and/or pharmacodynamic-driven approach to antimicrobial therapy yielded an impressive reduction in methicillin-resistant Staphylococcus aureus (MRSA) prevalence in the ICU, from 38% in 2002 to 15.6% in 2007, corresponding to a significant decrease in resistance rates from 9.3 to 3.3 MRSA isolates per 1000 patient-days. The results for Gram-negative pathogens (e.g., Pseudomonas aeruginosa, Escherichia coli) did not show statistically significant variations, but the total number of isolates of these bacterial species was relatively low. Important variations in antibiotic consumption were observed over time, with reductions in the consumption of vancomycin (-73%), teicoplanin (-95%), ceftazidime (-79%) and imipenem (-60%), along with huge increases in the consumption of oxacillin and anti-staphylococcal beta -lactams (at least 1550% for each) from 2003 to 2007. In addition, the programme led to a remarkable containment of drug expenditure. Despite a similar number of patients receiving therapy and a greatly increased consumption of last-generation, expensive drugs in the most recent years, the overall cost of antibiotic acquisition did not increase (109 627 euros in 2002 vs 115 492 euros in 2007). These results confirm that an integrated and multidisciplinary stewardship programme may contribute to the optimal use of currently available antimicrobial agents and can strongly help reduce antimicrobial resistance in the ICU.