Aerosolized colistin for the treatment of nosocomial pneumonia due to multidrug-resistant Gram-negative bacteria in patients without cystic fibrosis.

The management challenges of patients with nosocomial pneumonia are great because of resistance among the responsible pathogens. In this issue of Critical Care, Argyris Michalopoulos and colleagues describe the use of inhaled colistin in the treatment of multidrug-resistant Gram-negative nosocomial pneumonia in a small group of patients. Although seven of eight patients who received nebulized colistin showed clinical improvement, some patients also received other active antibiotics. Microbiological eradication was demonstrated in only four of the eight patients. Serum levels of colistin were not measured. In addition, although adverse events were not documented in patients receiving colistin, formal assessments for bronchoconstriction and neurological toxicity were not completed in this retrospective study. Although resistance to colistin in Gram-negative organisms has not evolved, the risk of breakthrough infection with Gram-positive and inherently resistant Gram-negative bacteria remains a concern. The results of this limited study do, however, suggest that further studies examining the use of nebulized colistin are merited.