Category: Professional Posters
Purpose: Appropriate utilization of empiric antibiotic therapy is crucial to effective management of Pseudomonas aeruginosa bacteremia (PAB). Pseudomonas is one of the most common nosocomial gram-negative bacilli presumed when attempting to discern infectious etiology. Swift utilization of appropriate broad-spectrum antibiotics is associated with decreased mortality and decreased recurrence of infection. Our study aimed to review the appropriateness of empiric antibiotics for PAB in order to guide future antimicrobial stewardship guidelines at our institution.
Methods: Retrospective chart review of all patients >18 years of age who were admitted to a single academic community hospital from 2015 to 2018 who had PAB throughout their hospitalization. The primary endpoint was the appropriateness of empiric antibiotic therapy, defined as receiving active therapy prior to the return of antimicrobial sensitivities that were susceptible to the empiric agents used. Additionally, patient demographics, length of stay, vasopressor requirement, and mortality data was collected.
Results: We identified 69 patients with PAB. The most common sources of infection included primary bacteremia/line infection (33.3%), urinary (29%) and intra-abdominal (17.4%). Based on the susceptibility reports, the most active agents were aminoglycosides (92.8% for gentamicin ; 97.1% for tobramycin) and cefepime (92.8%). Fifty nine out of 69 (85.5%) of patients received empiric therapy that tested susceptible. Among the non-susceptible isolates, four (5.8% of the total) were intermediate, five (7.2%) were resistant, and 1.4% were not tested. Piperacillin/tazobactam was the most common inappropriate empiric choice (55.5%) followed by meropenem (33.3%) and cefepime (11.1%). Overall mortality in our study was 15/69 (21.7%) with 14/15 (93.3%) patients receiving appropriate empiric therapy.
Conclusion: The results of this study demonstrate that across our patient population, 85.5% of patients received appropriate empiric antibiotics for PAB. increased risk of mortality was not demonstrated in our study, although studies have shown that delays in appropriate therapy are associated with increased mortality. Interestingly, the majority of mortalities occurred in patients receiving an antibiotic the isolate was susceptible to. This may be explained by the possibility for inappropriate dosing, which we did not investigate. We also conclude that in our institution, piperacillin/tazobactam may not be the preferred agent for empiric use when there is concern for pseudomonas bacteremia.