Double Lumen Tubes

How do you isolate the lungs? What techniques are there to inflate one lung and deflate the other so that a surgeon can work yet a patient can be oxygenated and ventilated? Well, one easy way is to push a normal endotracheal breathing tube too far down into the lungs so it becomes endobronchial. If you manage to get it into the side you want to ventilate, then you can breathe for that lung while allowing the other lung to deflate.

But the double lumen tube provides a much more sophisticated solution. One lumen acts as a normal endotracheal tube; it has a cuff that inflates within the trachea and an outlet below that cuff to allow positive pressure ventilation. But it also has a second lumen whose tip ends up in one of the mainstem bronchi. This has a second balloon and an opening to allow ventilation of just that lung. Most commonly we use left sided double lumen tubes because the anatomy of the right lung can be tricky to navigate (because the right upper lobe takes off very proximally). Most people get confused, but we can use a left sided tube for surgeries on either lung. If the surgeon needs the right lung deflated, we simply use the endobronchial lumen in the left mainstem to ventilate the lung. If the surgeon needs the left lung deflated, we raise both balloons and ventilate the tracheal lumen which will go down the right lung.

These tubes happen to be very large and so placing them requires a little more care and finesse than a normal intubation. And slight movements of the tube can cause us to lose the isolation, so we have to be vigilant and facile with the fiberoptic bronchoscope to check our position and adjust the tube positioning. Although its a labor intensive process, it's fun and challenges us to use a wide range of skills and knowledge.

Double lumen tube shown under GNU Free Documentation License, from Wikipedia.