Non-fiberoptic Bronchoscopy Lung Isolation Catheter Positioning

Background: The endotracheal tube (ETT) will move within the trachea when the head and neck are flexed or extended. The evidence shows that flexion of the head and neck results in the movement of the tip of ETT towards the carina, which is different from the extension of the head and neck, which leads to the movement of the cuff of ETT towards the vocal cord and the movement of the tip away from the carina. If ETT moves towards the carina, hypoxaemia may be caused by an accidental bronchial intubation. In addition, the carinal stimulation can cause tachycardia, hypertension or bronchospasm. If the tracheal tube moves outward the carina, the cuff may press and damage the vocal cord. An accidental extubation may follow if a further outward movement occurs, especially in children. Toung and colleagues reported that the carina only slightly changed the position related to the thoracic vertebrae; however, the vocal cord had a clear movement superiorly from C5 to C4 with the neck extension. Therefore, the distance from the vocal cord to the carina increased. The movement of the Upper airway, however, is more dramatic with the distance from the lips to the cords...