(644) The Critical Care Team and Patient Location Both Influence Antibiotic Resistance Patterns

Introduction: Antibiograms are often used to guide empiric treatment and direct stewardship efforts, but are often created based on hospital data. We previously showed that individual ICU's within a tertiary hospital had significantly different antibiotic resistance patterns. However, patients are often admitted to beds outside the primary ICU of the respective team managing their care. We hypothesize that resistance patterns may vary between different critical care teams and may require service-specific data to guide empiric antibiotic regimens.

Methods: We conducted a retrospective cohort study of susceptibility data for all cultures obtained from ICU patients over a 1-year period at an academic tertiary care hospital and identified which critical care team prescribed antibiotics. The critical teams included Pulmonary Critical Care (MICU), Surgical Critical Care (STICU), Neuroscience Critical Care (NSICU), Burns (BICU), or Surgical Subspecialty services (SURG). Contingency tables were analyzed using Chi-square test, with statistical significance at p< 0.05.

Results: Fifteen different species were identified from 585 total cultures. Statistically significant and clinically relevant differences in susceptibilities were noted for Acinetobacter baumanii, Escherichia coli, Enterococcus faecalis, Pseudomonas aeruginosa, and Staphylococcus aureus between critical care teams. A baumanii was 25% and 0% susceptible to ceftriaxone on the STICU and MICU teams respectively, but 100% susceptible for other teams. All A baumanii isolates for the NSICU team were resistant to cefepime, while all were sensitive for other services. E faecalis was 13% susceptible to linezolid for the BICU compared to 100% susceptible on the other critical care teams. P aeruginosa was susceptible to meropenem in 19% and 53% of isolates from the MICU and SURG teams respectively. S aureus was susceptible to clindamycin in 13% of isolates for the SURG teams while all other teams were greater than 70% susceptible.

Conclusions: Prescribing patterns and patient or disease characteristics of different provider teams affect the susceptibility patterns of bacterial isolates at our institution. A hospital- or community-specific antibiogram may not provide adequate data for empiric coverage and may overlook opportunities for improving stewardship.