Causative Pathogen Dictates Optimal Duration of Antimicrobial Therapy for Ventilator-Associated Pneumonia in Trauma Patients

BACKGROUND: Recent ventilator-associated pneumonia (VAP) guidelines recommend considering abbreviated therapy in patients with non-Pseudomonas aeruginosa VAP if clinical signs resolve. However, using an arbitrary day cutoff or clinical signs can be suboptimal for some, especially multiply injured patients, resulting in relapse and/or antibiotic resistance. Previously, we showed that repeat bronchoalveolar lavage (BAL) could guide antimicrobial duration for community-acquired VAP in trauma patients. The purpose of this study was to determine the appropriate duration of antimicrobial therapy for VAP in trauma patients secondary to hospital-acquired pathogens. STUDY DESIGN: Patients with VAP secondary to MRSA, Pseudomonas aeruginosa (PA), Acinetobacter baumannii (AB), Stenotrophomonas maltophilia (SM), or Enterobacteriaceae (ENB) during 6 years were evaluated. All received empiric antimicrobial therapy based on duration of ICU stay. Therapy was tailored based on culture data. Repeat BAL was performed on day 4 of appropriate therapy. Microbiological resolution was defined as <= 10(3) colony-forming units/mL. Recurrence was defined as >= 10(5) colony-forming units/mL on subsequent BAL performed within 2 weeks after completion of appropriate therapy. RESULTS: Six hundred and fifty-nine patients were identified. Seventy-seven percent of patients underwent repeat BAL: 96 with MRSA, 100 with AB, 139 with PA, 50 with SM, and 120 with ENB. The majority of patients with MRSA or PA achieved microbiological resolution after 14 days. Nearly 60% of patients with AB, SM, or ENB achieved microbiological resolution after 10 days. Overall recurrence was 2%. CONCLUSIONS: Repeat BAL provides objective evidence for VAP resolution in the face of potentially confounding clinical factors. Hospital-acquired VAP can be managed effectively by a defined course of therapy with a low recurrence. Duration of antimicrobial therapy for VAP in trauma patients should be dictated by the causative pathogen. (J Am Coll Surg 2011;212:476-486. (C) 2011 by the American College of Surgeons)