575. Effectiveness of Short vs Long Course Perioperative Antibiotics in Lung Transplant Recipients with Donor Positive Respiratory Cultures

BACKGROUND: Lung transplant recipients are at increased risk for infection in the early post-operative phase. Perioperative antibiotic (POA) practices are variable among transplant centers with sparse data regarding optimal antibiotic prophylaxis duration. This study aimed to evaluate the efficacy of short course (SC) (≤10 days) vs long course (LC) (≥11 days) POA in lung transplant patients. METHODS: This was a single-center, retrospective study of non-cystic fibrosis first time lung transplant recipients with donor positive cultures between Aug 2013 and Sept 2019. Patients who died within 14 days of transplant were excluded. Data collected included baseline characteristics, donor and recipient cultures, POA, and hospitalization details. The primary outcome was 30-day recipient freedom from donor-derived respiratory bacterial infection. Secondary outcomes included development of Clostridioides difficile infection (CDI), cumulative time on ventilator, post-op time to extubation, in-hospital all-cause mortality, and 30-day development of POA resistance. Descriptive statistics were used for analysis. Continuous variables were compared using the Wilcoxon rank sum test while categorical variables were compared using the chi-square or Fisher’s exact test. Statistical significance was defined as p< 0.05. RESULTS: A total of 147 patients were included (58 SC vs 89 LC). Median POA duration in the SC group was 6.5 days vs 13 days in the LC group (p< 0.0001). The primary outcome of 30-day freedom from donor-derived respiratory infection was present in 56 (97%) patients in the SC vs. 85 (96%) patients in the LC group (p= 1). There was no difference in development of CDI (p = 0.4), mortality (p = 1), or resistant organisms (p=0.28) while cumulative ventilator time and time to post-op extubation were longer in the LC group (p = 0.002 & 0.007, respectively). Methicillin-sensitive Staphylococcus aureus was the most common organism isolated from donors in the SC (23, 40%) and LC (48, 54%) groups. CONCLUSION: Among lung transplant recipients with positive donor cultures, short course POA was as effective as long course in preventing donor-derived bacterial pneumonia. Further studies are needed to assess heterogeneity in POA practices and optimal duration among transplant centers. DISCLOSURES: Brian C. Keller, MD, PhD, CareDx, Inc. (Grant/Research Support) Bryan A. Whitson, MD, PhD, Abbott Laboratories (Consultant)TransMedics OCS (Other Financial or Material Support, Serves on the Clinical Events Committee)