“…66,67 With small¯exible endoscopes (e.g., 2.2 mm OD), even premature infants can be endoscoped through the endotracheal tube. 70 However, signi®cant oxygen desaturation and even transient bradycardia were observed in 14% of such procedures despite the use of an adapter allowing uninterrupted ventilation. Proposed uses have been to check for tube obstruction, obviating the change of the endotracheal tube, 68 demonstrating the exact position of the tip of the tube, 69 and the diagnosis of airway obstruction in lobar overin¯ation.…”