(520) Incidence of Multidrug-Resistant VAP Pathogens in Three Geographically Distinct Trauma Units

Introduction: Three geographically separate intensive care units (ICU) containing patients admitted to the same trauma service will have similar incidences of multidrug resistant (MDR) organisms causing ventilator associated pneumonia (VAP) within the first seven days of admission.

Methods: Patients ≥ 18 years old, admitted to a trauma ICU (TICU) with similar multidisciplinary teams and treatment pathways, and confirmed VAP (bronchoalveolar lavage [BAL] performed ≤7 days after admission and growing ≥105 colony forming units) were eligible for inclusion. Patients were grouped based on admission location: TICU-1, TICU-2, or TICU-3. Primary outcome was incidence of MDR VAP (inclusive of MRSA and Pseudomonas aeruginosa). Secondary outcomes were incidence of inappropriate empiric antimicrobial therapy (IEAT) and determination of risk factors for MDR VAP. Chi-squared and multivariable logistic regression analyses were used accordingly.

Results: A total of 320 patients were included (TICU-1: 171 patients, TICU-2: 73 patients, and TICU-3: 76 patients). The incidence of MDR VAP was not different between locations at 45.8%, 50.8%, and 42.4%, respectively (p=0.63). MDR gram(-) organisms were more prevalent in TICU-1 (69.2%) than in TICU-2 (51.5%) or TICU-3 (32.1%) (p=0.003). IEAT was also similar across all locations; however, IEAT was significantly higher for MDR gram(-) organisms in TICU-1 (69.4%) vs TICU-2 (51.6%) or TICU-3 (40.6%) and correspondingly highest for MDR gram(+) organisms in TICU-3 (59.4%) vs TICU-1 (30.6%) or TICU-2 (48.4%) (p=0.02). Regression analyses revealed polymicrobial infection and cefazolin receipt prior to BAL as significant predictors of MDR VAP in all locations.

Conclusions: Geographical location of critically ill trauma patients admitted to the same service did not influence overall incidence of MDR VAP, but differences in morphology of MDR organisms were observed. IEAT rates for both gram(-) and gram(+) organisms in different units may necessitate use of broader spectrum empiric therapy for VAP. Cefazolin use increased odds of MDR VAP, which could have important implications due to widespread use in trauma. Polymicrobial infection may also indicate that broader spectrum empiric antimicrobial therapy is required.