Tenacious tracheal secretions may accumulate.
Methods for tracheal graft research have presented persistent challenges to investigators, and three-dimensional (3D printed biosynthetic grafts offer one potential development platform.
It has been suggested that biofilm formation in the tracheal tubes is a source of persistent bacterial lung colonisation [ 47] because the film acts as a reservoir for infecting pathogens.
Suspected VAP was defined as the development of persistent pulmonary infiltrates on chest radiographs combined with purulent tracheal secretions and/or body temperature ≥38.5°C or ≤36.5°C and/or peripheral blood leukocyte count ≥10·10/L or ≤4·10/L.
In all ICUs, as previously reported [ 8, 9], VAP was suspected based on the development of persistent pulmonary infiltrates on chest radiographs combined with purulent tracheal secretions, and/or body temperature ≥ 38.5°C or ≤ 36.5°C, and/or peripheral blood leukocyte count ≥ 10 × 10 / L(Giga/liter) or ≤ 4 × 10 / L.
The diagnosis of VAP was established when a new, persistent, progressive radiographic lung infiltrate was present ≥48 hours following tracheal intubation and when two or more of the following clinical criteria were met: (1) new onset of purulent bronchial secretions; (2) body temperature >38.8°C or <35.5°C; and (3) white blood cell count >10,000/mm or <4,000/mm[ 7].
Tracheal or bronchial injury should be suspected in patients with persistent or increasing pneumothorax, despite continuous intercostal drainage.
In four critically ill patients with persistent pulmonary infiltrates of unknown origin and isolation of HSV-1 from tracheal aspirate or bronchoalveolar lavage fluid, at 7 (1–11) days after start of mechanical ventilatory support, a pulmonary leak index (PLI) for Gallium (Ga -transferrin (upper limit of normal 14.1 × 10-3/min) was measured.
It also requires one of the following to be satisfied: new and persistent infiltrates on chest radiograph; same micro-organism isolated from pleural fluid and tracheal secretions, or radiographic cavitation, or histological proof of pneumonia; or positive cultures from bronchoalveolar lavage (≥ 104 colony-forming units/ml).
Suspicion of hospital-acquired pneumonia was based on American Thoracic Society guidelines [19],[20] and was defined as: more than 48 h after hospital admission, new or persistent infiltrate on chest X-ray associated with at least two of the following: purulent tracheal secretions, temperature >38°C, and leukocyte count >11,000 or <4,000/mm3.
