[Changes of peripheral airways through mechanical ventilation in acute respiratory failure].

To evaluate the morphologic changes in the peripheral airways associated with positive pressure ventilation, fine fiberoptic bronchoscopy (1.8 mm outer diameter) was performed in 12 patients who had no history of prior pulmonary failure. In 19 examinations, the main morphologic findings were paleness and bronchial dilatation in the peripheral airways where increased secretions, pigmentation and stenosis or collapse were also observed. Patients with bronchial dilatation had longer periods of mechanical ventilation (17 +/- 8 days) compared to those without dilation (10 +/- 5 days). The structural destruction in the peripheral airways observed in patients on prolonged positive pressure mechanical ventilation suggests that barotrauma may be more widespread than previously recognized.