Inhaled nitric oxide decreases the bacterial load in a rat model of Pseudomonas aeruginosa pneumonia.

Gaseous nitric oxide (NO) is bactericidal in vitro. However whether and how it can be used for the treatment of bacterial lung infections in patients with cystic fibrosis is unclear. Here we assessed the bactericidal effect of intermittently inhaled 160 ppm NO for 30 min every 4 h in a Pseudomonas aeruginosa pneumonia model in rats. NO significantly reduced P. aeruginosa colony count in rat lungs but did not affect neutrophil myeloperoxidase function methemoglobin percentage nor plasma nitrite/nitrate levels. This regimen warrants exploration in infected patients with cystic fibrosis.