Antimicrobial Therapy Duration for Bloodstream Infections Caused by Pseudomonas aeruginosa or Acinetobacter baumannii-calcoaceticus complex: A Retrospective Cohort Study

Abstract

Background: Ideal therapy duration for Pseudomonas aeruginosa or Acinetobacter baumannii-calcoaceticus complex (ABC) bloodstream infections (BSI) is not defined, especially in the context of carbapenem resistance. In this study, we compared short- (≤7 days) and long-term (>7 days) antimicrobial therapy duration for these infections. Methods: We performed a retrospective cohort study in two tertiary-care hospitals in Porto Alegre, Brazil, from 2013 to 2019. Eligible patients aged ≥18 years were included and excluded for the following criteria: polymicrobial infections, treatment with non-susceptible antibiotics, complicated infections, or early mortality (<8 days of active antimicrobial therapy). The 30-day mortality risk was evaluated using a Cox regression model. Results: We included 237 BSI episodes, 51.5% caused by ABC and 48.5% by Pseudomonas aeruginosa. Short-term therapy was not associated with 30-day mortality, adjusted hazard ratio 1.01, 95% confidence interval 0.47–2.20, p = 0.98, when adjusted for Pitt score (p = 0.02), Charlson Comorbidity Index score (p < 0.01), and carbapenem resistance (p < 0.01). Among patients who survived, short-term therapy was associated with shorter hospital stay (p < 0.01). Results were maintained in the subgroups of BSI caused by carbapenem-resistant bacteria (p = 0.76), ABC (p = 0.61), and Pseudomonas aeruginosa (p = 0.39). Conclusions: Long-term therapies for non-complicated Pseudomonas aeruginosa and ABC BSI were not superior to short-term therapy for 30-day mortality.

Is Short-Course Antibiotic Therapy Suitable for Pseudomonas aeruginosa Bloodstream Infections in Onco-hematology Patients With Febrile Neutropenia? Results of a Multi-institutional Analysis

“…Siddharth Swamy et al [ 15 ] compared the effectiveness of short-course and prolonged-course treatments in a retrospective analysis of 178 patients with gram-negative BSI and found that short-course therapy for gram-negative bacteremia yielded comparable rates of clinical response (78.6% vs 80.6%, P = .202) and microbiological cure (83.3% vs 91.7%, P = .690). Rodrigues et al [ 16 ] indicated that short-term therapy was not associated with 30-day mortality(hazard ratio [HR] = 1.01, 95% CI .47–2.20, P = .98), Bae et al [ 17 ] included 290 uncomplicated PA BSI and found that no significant difference in the risk of recurrence or 30 day mortality between the prolonged-course and short-course groups (HR = 0.68, 95% CI = .34–1.36, P = .28) and the recurrence of PA infection within 180 days (HR = 0.57, 95% CI = .29–1.10, P = .09). However, several retrospective studies involving immunocompromised populations are as follows.…”

Treatment of Acinetobacter baumannii

“…There is a lack of consensus for specific duration for MDR infections and in particular CRAB. Studies on patients with MDR infections with VAP and BSI have used a range of 7-22 days of therapy [101][102][103]. RCT and prospective studies on VAP have shown no difference in mortality with shorter courses of 3-8 days [104][105][106].…”