Treating Staphylococcus aureus infections in an intensive care unit at a University Hospital in Brazil

Background Optimizing antimicrobial therapy is important for treating patients who are critically ill with Staphylococcus aureus infection, and susceptibility tests are necessary. Objective The aim of the present study was to evaluate antibacterial therapy after susceptibility testing of S. aureus infections. Setting The setting was an intensive care unit at a University Hospital in Brazil. Methods An observational and retrospective study was conducted over 6 years. The antimicrobials that were used for S. aureus infection treatment were calculated as the defined daily dose per 1000 patient-days (DDD₁₀₀₀). Antimicrobial susceptibility data were obtained by reviewing bacteriological tests. Patient profiles and treatment were determined by analyzing patient charts. Results Methicillin-resistant S. aureus (MRSA) was prevalent in this study (76.13 %). Patients who were infected with MRSA had total antimicrobial consumption that was three-times higher (9567.2 DDD₁₀₀₀) than patients who were infected with methicillin-susceptible S. aureus (MSSA; 3101.1 DDD₁₀₀₀). The average length of stay in the intensive care unit was 19 days (interquartile range 17 days) for MSSA and 20 days (interquartile range 20 days) for MRSA. Mortality in patients who were infected with MSSA was higher (52.17 %) than in patients who were infected with MRSA (33.80 %), and de-escalation was not identified in 73.90 % of MSSA patients.