Figure 49-17 Use of left-sided and right-sided double-lumen endotracheal tubes for left and right lung surgery (as indicated by the clamp). A, When surgery is performed on the right lung, a left-sided double-lumen endotracheal tube should be used. B, When surgery is performed on the left lung, a right-sided double-lumen endotracheal tube can be used. However, because of uncertainty about alignment of the right upper lobe ventilation slot with the right upper lobe orifice, a left-sided double-lumen endotracheal tube can also be used for left lung surgery. C, If the left lung surgery requires a clamp to be placed high on the left main stem bronchus, the left endobronchial cuff should be deflated, the left-sided double-lumen endotracheal tube pulled back into the trachea, and the right lung ventilated through both lumens (use the double-lumen endotracheal tube as a single-lumen tube). (From Benumof JL: Anesthesia for Thoracic Surgery. Philadelphia, WB Saunders, 1987.)