Effect of extended infusion of meropenem and nebulized amikacin on Gram-negative multidrug-resistant ventilator-associated pneumonia

BACKGROUND: Ventilator-associated pneumonia (VAP) due to multidrug-resistant organisms (MDROs) is associated with a significant mortality in the Intensive Care Unit (ICU). The aim of this study was to compare the efficacy and safety of extended infusion of meropenem and nebulized amikacin on VAP caused by Gram-negative MDRO versus intravenous (IV) meropenem and amikacin alone. METHODOLOGY: A randomized nonblinded controlled trial was performed on ninety patients with VAP. Patients were randomized into three equal groups: Group I received IV amikacin 20 mg/kg/24 h and meropenem 2 g over 30 min/8 h. Group II received the same as Group I in addition to nebulized amikacin 25 mg/kg/day every 8 h. Group III received IV amikacin 20 mg/kg/24 h, nebulized amikacin 25 mg/kg/day every 8 h, and meropenem 2 g diluted in 240 ml normal saline over 3 h/8 h. The primary outcome was the clinical outcome of VAP. Secondary outcomes were microbiological outcome, VAP-related mortality, duration of MV, ICU stay, and nephrotoxicity. RESULTS: Group II and Group III compared to Group I showed higher incidence of clinical cure (53.33% in Group II and 66.67% in Group III vs. 26.67% in Group I, P = 0.007). Group II compared to Group I showed significant reduction in ventilator days (5.32 ± 1.86 vs. 7.3 ± 2.1 days, respectively, P < 0.001) and reduction in ICU days (11.87 ± 2.6 vs. 15.3 ± 3.1 days, respectively, P < 0.001). Group III compared to Group II showed significant reduction in ventilator days (4.22 ± 1.32 vs. 5.32 ± 1.86, respectively, P = 0.011) and highly significant reduction in ICU days (9.21 ± 1.17 vs. 11.87 ± 2.6, respectively, P < 0.001). All groups were comparable as regards nephrotoxicity or mortality. CONCLUSIONS: Adding nebulized amikacin to systemic antibiotics in patients with VAP caused by Gram-negative MDRO may offer efficacy benefits, and the use of extended infusions of meropenem could improve the clinical outcomes in critically ill populations.