Effect of Positive Perioperative Donor and Recipient Respiratory Bacterial Cultures on Early Post-transplant Outcomes in Lung Transplant Recipients

Background: It is standard practice to administer prophylactic antibiotics post-lung transplant (LT) for which patients at Emory University Hospital (EUH) receive empiric ceftazidime and vancomycin. However, there are no studies evaluating the impact of culture positivity and the appropriateness of the empiric antibiotics. The purpose of this study was to evaluate early post-transplant outcomes of culture positive appropriate empiric regimens, culture positive inappropriate empiric regimens and culture negative LT recipients.

Methods: Adult patients who received a LT at EUH between January 1, 2010 and August 31, 2015 were chart reviewed and stratified into the three groups previously mentioned. Appropriate antibiotics were defined as bacteria sensitive to the empiric regimen. The primary endpoint was 30 day mortality. Secondary endpoints included hospital length of stay (LOS), intensive care unit (ICU) LOS, percent neutrophil count in a bronchoalveolar lavage (BAL), presence of airway ischemia and appropriateness of the empiric antibiotic regimen.

Results: Nine, zero and four patients expired within 30 days in the culture positive appropriate (n=113), culture positive inappropriate (n=5), and culture negative groups (n=29) (p=0.564). The mean hospital LOS was 26, 30, and 23 days respectively (p=0.753). Mean ICU LOS was 12, 12, and 11 days (p=0.898). The respective percent neutrophil counts in the BAL were 64.4, 36.4, and 59.7 (p=0.177). The presence of airway ischemia was only documented in eight patients all in the culture positive appropriate group. Staphylococcus aureus isolates were 81% and 74% susceptible to oxacillin in donor and recipient cultures respectively and were both 100% susceptible to vancomycin. All Pseudomonas aeruginosa isolates were sensitive to empiric ceftazidime.

Conclusion: While there does not appear to be an association between empiric antibiotic appropriateness and 30 day mortality, hospital length of stay or ICU length of stay in post-LT recipients, this study does pose several questions. First, if broad spectrum antibiotics are necessary and second, what are the long term consequences of these empiric broad spectrum antibiotics. Future areas for research include the promotion of resistance, morbidity such as graft failure, and all-cause mortality.