2207. Narrowing Antibiotic Spectrum of Activity for Trauma-Associated Pneumonia Through the Use of a Disease-Specific Antibiogram

BACKGROUND: Organism susceptibilities for trauma-associated pneumonia (TAP) differ from those in other groups of patients, including the critically ill. The purpose of this study was to identify common organisms and their susceptibilities in the respiratory isolates of trauma patients diagnosed with pneumonia within the first 7 days of hospital admission, and to create a disease-state antibiogram specific to TAP to guide empiric antibiotic therapy in this patient population. METHODS: This study was an IRB-approved, retrospective chart review of adult trauma patients with pneumonia admitted between September 1, 2015 and August 31, 2018 were evaluated. Patients included were diagnosed with and treated for pneumonia, with respiratory cultures drawn within the first 7 days of admission; both culture-positive and culture-negative patients were included. Subgroup antibiograms were made for a diagnosis made on days 1–3, 4–5, and 6–7. RESULTS: There were 131 patients included with a median age of 45; 85% were male, and 31% were illicit drug users. The majority of patients (63%) had ventilator-associated pneumonia, and most respiratory samples (77%) were obtained via bronchiolar lavage. Cultures were positive in 109 patients and negative in 22. There were 144 total isolates; 54% were Gram-negative bacteria. The most common Gram-negative pathogens were Haemophilus influenzae (16%) and Klebsiella pneumoniae (15%). The most common Gram-positive pathogen was Staphylococcus aureus; 9% of all patients grew methicillin-resistant S. aureus. With culture-negative patients counted as susceptible, ceftriaxone monotherapy and ceftriaxone + vancomycin susceptibility were 85% and 94% of patients, respectively. Susceptibilities to cefazolin, ampicillin/sulbactam, cefepime, piperacillin/tazobactam, and levofloxacin were 49%, 69%, 91%, 90%, and 92%, respectively. Illicit drug use and day of pneumonia diagnosis did not appreciably affect antibiotic susceptibilities. CONCLUSION: For TAP diagnosed within the first 7 days of hospital admission, ceftriaxone monotherapy is adequate as empiric therapy, including in ventilated patients. The addition of vancomycin can be considered in patients with MRSA risk factors or who are critically ill. DISCLOSURES: All authors: No reported disclosures.