The effect of fibreoptic bronchoscopy in acute respiratory distress syndrome: experimental evidence from a lung model.

Flexible bronchoscopy is essential for appropriate care during mechanical ventilation, but can significantly affect mechanical ventilation of the lungs, particularly for patients with acute respiratory distress syndrome. We aimed to describe the consequences of bronchoscopy during lung-protective ventilation in a bench study, and thereby to determine the optimal diameter of the bronchoscope for avoiding disruption of the protective-ventilation strategy during the procedure. Immediately following the insertion of the bronchoscope into the tracheal tube, either minute ventilation decreased significantly, or positive end-expiratory pressure increased substantially, according to the setting of the inspiratory pressure limit. The increase in end-expiratory pressure led to an equivalent increase in the plateau pressure, and lung-protective ventilation was significantly altered during the procedure. We showed that a bronchoscope with an external diameter of 4 mm (or less) would allow safer bronchoscopic interventions in patients with severe acute respiratory distress syndrome.