458. Evaluation of Antimicrobial Stewardship Models in the Intensive Care Unit: Impact on Antimicrobial Selection and Emergence of Resistance
Session: Poster Session: Hospital-acquired and Transplant Infections
Friday, October 30, 2009: 12:00 AM
Room: Poster Hall A
Background: the impact of two antimicrobial stewardship (AS) models on relevant outcomes of critically ill adults was evaluated.
Methods: a prospective quasi-experimental study was carried out in the Intensive Care Units (ICU) of a university-affiliated public hospital in Atlanta, GA. Critically ill adults receiving empiric imipenem or piperacillin-tazobactam were considered eligible. Outcomes for three different phases were compared: baseline period (B, Feb-May 2006); Model 1 period (M1, Oct 2006-July 2007); Model 2 period (M2, Sep 2008-Feb 2009). No AS was performed during B. During M1, AS consisted of uninvited patient evaluation by a Board Certified Infectious Diseases (ID) Specialist, and communication of recommendations to the primary ICU team (Surgical or Medical), using a written document discussed with the Critical Care Pharmacist. During M2, an ID specialist participated in interdisciplinary rounds with the Medical ICU team three times per week. Main outcomes were mortality, appropriateness of antibiotic selection and emergence of resistance. Logistic regression analysis was used to adjust for baseline differences between groups.
Results: of 692 total cases, 194 were included during B, 415 during M1 and 83 during M2. Mortality was not significantly different between groups. M1 and M2 were associated with higher rates of appropriate antimicrobial selection (B, 70%; M1, 78%; M2, 82%; p=0.042) and lower rates of emergence of resistance (B, 31%; M1, 25%; M2, 17%; p=0.033). Multivariate logistic regression analysis showed that AS was independently associated with improvement of appropriate antimicrobial selection (OR, 1.51; 95% CI, 1.02-2.2) and prevention of antimicrobial resistance (OR, 0.61; 95% CI, 0.42-0.9). The association was strongest for M2.
Conclusion: the tested antimicrobial stewardship models had an influence on antimicrobial prescription patterns in the ICU with a favorable impact on the emergence of antimicrobial resistance. Larger and multi-center studies are needed to confirm our findings.
Carlos DiazGranados, MD, MS, Emory University School of Medicine, Atlanta, GA and  C. A. DiazGranados, None.