Aerosolized plus Intravenous Colistin versus Intravenous Colistin Alone for the Treatment of Ventilator-Associated Pneumonia: A Matched Case-Control Study

(See the editorial commentary by Paterson and Rogers, on pages 1245-1247.) Objectives. The incidence of ventilator-associated pneumonia (VAP) due to multidrug-resistant (MDR) organisms is increasing. Intravenous (IV) colistin or aerosolized (AS) plus IV colistin have been recently used to treat these life-threatening infections. The purpose of this study was to compare the efficacy and safety of AS plus IV colistin versus IV colistin alone for patients with MDR VAP due to gram-negative bacteria. Methods. A retrospective matched case-control study was performed at the Intensive Care Unit of the University Hospital of Heraklion, Greece, from January 2005 through December 2008. Forty-three patients with VAP due gram-negative MDR pathogens received AS plus IV colistin and were matched on the basis of age and Acute Physiology and Chronic Health Evaluation II score with 43 control patients who had received IV colistin alone. Results. Demographic characteristics, clinical status, and gram-negative isolated pathogens were similar between the 2 treatment groups. Acinetobacter baumannii (66 cases [77%]) was the most common pathogen, followed by Klebsiella pneumoniae (12 cases [14%]) and Pseudomonas aeruginosa (8 cases [9.3%]). No colistin-resistant strains were isolated from patients in either group. No significant differences between the 2 groups were observed regarding eradication of pathogens (Pp. 679), clinical cure (Pp. 10), and mortality (Pp. 289). Eight patients (19%) in each treatment group developed reversible renal dysfunction. No AS colistin-related adverse events were recorded. Conclusions. Addition of AS colistin to IV colistin did not provide additional therapeutic benefit to patients with MDR VAP due to gram-negative bacteria.