Evaluation of Adjunctive Aminoglycoside Therapy Compared to β-Lactam Monotherapy in Critically Ill Patients with Gram-Negative Bloodstream Infections.

Abstract

Background/Objectives: Gram-negative bloodstream infections (GN-BSIs) in the critically ill carry significant mortality, which is exacerbated by delays in appropriate therapy. To improve the time to effective therapy, aminoglycosides are often recommended as empiric adjunctive antimicrobials. However, there is a paucity of clinical data supporting this practice. This study's objective was to evaluate the safety and efficacy of adjunctive aminoglycosides compared to β-lactam monotherapy in patients admitted to the intensive care unit (ICU) with GN-BSI. Methods: This was a retrospective, propensity-matched cohort study of critically ill patients with GN-BSI. The primary outcome was 15-day all-cause mortality. The secondary endpoints evaluated included 30-day mortality, ICU-free survival days, 60-day relapse, 30-day readmission, development of acute kidney injury (AKI), and new resistance. Results: A total of 209 propensity-matched patients were included for analysis: 136 received β-lactam monotherapy and 73 received adjunctive aminoglycoside. The primary outcome of 15-day all-cause mortality was not significantly different between groups (17% vs. 21%; p = 0.644). Additional secondary endpoints of 30-day mortality (22% vs. 25%), ICU-free survival (12.1 vs. 12.2 days), 60-day relapse (3.3% vs. 7.4%), and 30-day readmission (23% vs. 18%) did not yield significant differences. The proportion of AKI was higher in the adjunctive aminoglycoside group but was not found to be significantly different (26.5% vs. 37%). Conclusions: The use of adjunctive aminoglycosides for GN-BSI did not affect clinical outcomes in the critically ill.