Optimising the duration of antibiotic therapy for ventilator-associated pneumonia

Ventilator-associated pneumonia (VAP) has traditionally been treated with a 14–21day course of antibiotics. However, prolonged antibiotic therapy is associated with the emergence of multidrug-resistant strains, as well as higher toxicity and costs. In a large, randomised, controlled trial in patients with microbiologically confirmed VAP who received appropriate empirical antibiotic therapy, an 8-day antibiotic regimen was not associated with excess mortality or more episodes of recurrent pulmonary infection compared with a 15-day regimen. Amongst patients who developed recurrent infection, multidrug-resistant pathogens emerged less frequently in the group receiving 8 days of antibiotic therapy. The 8-day regimen was also not associated with excess mortality in the subgroup with VAP caused by nonfermentative Gram-negative bacilli, mostly Pseudomonas aeruginosa, although recurrent infections occurred more often. Pending confirmatory studies, an 8-day course of antibiotic therapy may be appropriate for many patients with ventilator-associated pneumonia, providing that initial antibiotic therapy is appropriate, the clinical course is favourable and extreme vigilance is maintained after stopping antibiotics. Patients whose initial treatment regimen was inappropriate, those infected with difficult-to-treat pathogens such as Pseudomonas aeruginosa, and immunocompromised patients and others at high risk for relapse are likely to require a longer duration of antibiotic therapy.