Predictors of 30-day mortality and hospital costs in patients with ventilator-associated pneumonia attributed to potentially antibiotic-resistant Gram-negative bacteria

Objective: To identify predictors of 30-day mortality and hospital costs in patients with ventilator-associated pneumonia (VAP) attributed to potentially antibiotic-resistant Gram-negative bacteria (PARGNB) [Pseudomonas aeruginosa, Acinetobacter species, and Stenotrophomonas maltophilia]. Design: A retrospective, single-center, observational cohort study. Setting: Barnes-Jewish Hospital, a 1,200-bed urban teaching hospital. Patients: Adult patients requiring hospitalization with microbiologically confirmed AIAP attributed to PARGNB. Interventions: Retrospective data collection from automated hospital, microbiology, and pharmacy databases. Measurements and main results: Seventy-six patients with VAP attributed to PARGNB were identified over a 5-year period. Nineteen patients (25.0%) died during hospitalization. Patients receiving their first dose of appropriate antibiotic therapy within 24 h of BAL sampling had a statistically lower 30-day mortality rate compared to patients receiving the first dose of appropriate therapy > 24 h after BAL (17.2% vs 50.0%; p = 0.005). VAP due to Acinetobacter species was most often initially treated with an inappropriate antibiotic regimen, followed by S maltophilia and P aeruginosa (66.7% vs 33.3% vs 17.2%; p = 0.017). Overall, total hospitalization costs were statistically similar in patients initially treated with an inappropriate antibiotic regimen compared to an appropriate regimen ($68,597 +/- $55,466 vs $86,644 +/- $64,433; p = 0.390). Conclusions: These data suggest that inappropriate initial antibiotic therapy of microbiologically confirmed VAP attributed to PARGNB is associated with greater 30-day mortality. High rates of VAP attributed to antibiotic-resistant bacteria (eg, Acinetobacter species) may require changes in the local empiric antibiotic treatment of VAP in order to optimize the prescription of appropriate initial therapy.