Fig. 9. Bacterial burden in tracheal aspirates obtained in critically ill patients with ventilator-associated tracheobronchitis at baseline and 1 and 2 weeks later. Twenty-four patients received intravenous antibiotics plus nebulization of saline (placebo) until extubated. Nineteen received intravenous antibiotics plus nebulization of either vancomycin or gentamicin (AA) until extubated. The quantity of bacterial growth was assessed on a graded scale of 0–4 from semiquantitative cultures. Decrease in tracheal colonization was exclusively observed in patients receiving aerosolized antibiotics. (Reprinted from Ref. 76with the permission of the publisher.) AA = aerosolized antibiotics.