How should we treat acinetobacter pneumonia?

To describe recent data about Acinetobacter baumannii pneumonia epidemiology and the therapeutic options including adjunctive nebulized therapy. A. baumannii is a major cause of nosocomial pneumonia in certain geographic areas affecting mainly debilitated patients, with prolonged hospitalization and broad-spectrum antimicrobials. Inappropriate empirical treatment has clearly been associated with increased mortality in A. baumannii pneumonia. Carbapenems may not be considered the treatment of choice in areas with high rates of carbapenem-resistant A. baumannii. Nowadays, polymyxins are the antimicrobials with the greatest level of in-vitro activity. Colistin is the antimicrobial most widely used although polymyxin B is associated with less renal toxicity. It is clear that lung concentrations of polymyxins are suboptimal in a substantial proportion of patients. This issue has justified the use of combination therapy or adjunctive nebulized antibiotics. Current evidence does not allow us to recommend combination therapy for A. baumannii pneumonia. Regarding nebulized antibiotics, it seems reasonable to use in patients who are nonresponsive to systemic antibiotics or A. baumannii isolates with colistin minimum inhibitory concentrations close to the susceptibility breakpoints. Cefiderocol, a novel cephalosporin active against A. baumannii, may represent an attractive therapeutic option if ongoing clinical trials confirm preliminary results. The optimal treatment for multidrug-resistant A. baumannii pneumonia has not been established. New therapeutic options are urgently needed. Well designed, randomized controlled trials must been conducted to comprehensively evaluate the effectiveness and safety of nebulized antibiotics for the treatment of A. baumannii pneumonia.