Abstract: An endotracheal tube (12) ventilates air from the lungs of a patient when inserted into the trachea. A second flexible tube (14) is closely joined to the endotracheal tube (12) in a side-by-side relation. The second flexible tube (14) slidably receives a catheter or endobronchial blocker (16) which has an inflatable cuff (32). The cuff (32) is maneuvered into the right or left bronchus of the patient by sliding and rotating the catheter or bronchial blocker (16) into a position to occlude the selected bronchus. A tracheal cuff (18) is disposed around the endotracheal tube (12) and the second flexible tube (14). When inflated, the tracheal cuff (18) engages the walls of the trachea to reduce passage of air and to secure the position of the endotracheal tube (12).