Inhaled antibiotics, pneumonia and bacterial resistance in the ICU

Abstract

Rationale: Ventilator-associated infection fails to respond to therapy in 50% of cases while IV antibiotics increase bacterial resistance. Previous studies using aerosol antibiotics (AA) with single agents guided by Gram-stain improved clinical success and decreased resistant organisms in mechanically ventilated patients (CCM2008, AJRCCM 2014). In the present study, we examined patients receiving broad-spectrum AA e.g. both inhaled vancomycin and gentamicin vs. placebo. All patients were on appropriate systemic antibiotics for their pathogens at the time of randomization. Methods: Patients with purulent secretions growing pathogenic isolates were randomized to aerosolized vancomycin and gentamicin administered for 14 days or until extubation. Seven patients received active drugs and 9 received placebo. Bacterial growth of tracheal aspirates was measured by semiquantitative cultures. Clinical pulmonary infection score (CPIS) was used to assess clinical response. Results: Systemic therapy with placebo aerosol did not affect deep lung infection and was associated with increasing bacterial resistance (FigureA, B). In the presence of AA deep respiratory infection resolved (6/7, FigureA). AA eradicated pathogens in all patients except for one positive culture after therapy (FigureB). Conclusion: AA may enhance the resolution of respiratory infection and concomitantly reduce the incidence of resistant organisms in the ICU.