LATE-BREAKING ABSTRACT: Nebulizedversusintravenous amikacin in ventilator-associated pneumonia Caused bypseudomonas aeruginosa

Background: In experimental models of pneumonia, nebulized amikacin provides greater lung concentration and more efficient bacterial killing than intravenous (IV) administration. Aims and Objectives: To compare the efficacy of nebulized versus IV amikacin in ventilator-associated pneumonia (VAP) caused by Pseudomonas aeruginosa. Primary endpoint was clinical cure rate. Methods: We did a 5-year before and after observational cohort study. From Janunary 2011 to August 2013, consecutive patients with VAP caused by P aeruginosa treated with IV amikacin were enrolled. From September 2013 to February 2016, consecutive patients with VAP caused by P aeruginosa receiving nebulized amikacin were enrolled. In both periods, amikacin for 1-5 days was combined with an IV β-lactam for 10-14 days. Aerosol was delivered using vibrating plate nebulizer. Results: One hundred and fifty-four patients were studied, 79 in the IV group and 75 in the nebulized group . After treatment, clinical cure rate was 72% in aerosol group and 58% in IV group, the difference was significant between the two groups after adjusting for Simplfied Acute Physiology Score II (p = 0.02). The odd ratio for the clinical cure rate in aerosol group compared with IV group was 2.35 (95% CI: 1.14 – 4.85). The median duration of mechanical ventilation after treatment was [10 (5-18) days vs . 13 (5-21) days, p = 0.46]. ICU mortality was not different between groups (19% vs. 23%, p = 0.53). Conclusions: In this 2-period study, nebulization of amikacin associated with IV β-lactam provides better clinical cure rate than combined IV amikacin and IV β-lactam in patients with VAP caused by P aeruginosa .