Evaluating Cefepime Dosing Strategies in Pseudomonas aeruginosa Bacteremia: A Retrospective Cohort Analysis.

BACKGROUND: Pseudomonas aeruginosa (PA) bacteremia is associated with poor clinical outcomes.

OBJECTIVE: The purpose of this study was to evaluate treatment effect and patient outcomes from different antimicrobials for PA bacteremia from 2020 to 2022.

METHODS: This was a retrospective review of 2020 to 2022 hospitalized patients with PA bacteremia at our institution. Patients from January 2020 to July 2022 with culture-positive PA were identified. Data collected included demographics, hospitalization and drug treatment length, vasopressor use or mechanical ventilation, and admission acute and physiologic health evaluation II score (APACHE II) score and hospital mortality. Directed therapy for PA, including dose, interval, and minimal inhibitory concentration (MIC) data, was evaluated. Data were analyzed by SPSS. Data are presented as mean ± SD or percentage. A priori significance was P ≤ 0.05.

RESULTS: A total of 111 PA bacteremias occurred from 2020 to 2022; 65% of patients were male. Mean (± SD) age was 71 ± 13 years, and weight was 89.7 ± 23 kg. Mean hospitalization length and duration of antibiotics were 12 ± 13 days and 7.1 ± 5.9 days, respectively. The PA bacteremia was treated with piperacillin-tazobactam (45%) or cefepime (43%). Thirty- seven (33%) PA-infected patients expired. Significantly more 8 of 18 (44%) cefepime patients died when receiving 4 g/d (1 g q 6 h) compared with 1 (9%) of 11 receiving 6 g/d (2 g q 8 h) (P < 0.05). The APACHE II score was significantly higher for expired patients (survival 13.9 ± 5.7; expired 22 ± 8.3 group, P < 0.001).

CONCLUSIONS AND RELEVANCE: The APACHE II score was significantly higher for PA bacteremic patients who expired. Treatment of the bacteremia with cefepime 4 g/d resulted in significant mortality compared to 6 g/d.