There are many organizations that provide excellent continuing education in avian medicine. If a bird needs to have surgery performed on the beak, or in the mouth area, instead of placing the breathing tube into the windpipe (correctly called the trachea), a tube can be placed into an air sac through a hole made in the bird elsewhere on the body.
The oxygen and anesthetic gas can then be administered through the air sac, keeping the beak and mouth free of tubes in order to safely perform surgery there! How cool is that?
An air sac tube can also be placed when a bird is having difficulty breathing due to an obstruction in the trachea or related areas. For example, if a seed is inhaled into the windpipe, it may prevent the air from passing in and out of the bird. If the owner can get the bird to an avian vet immediately, the vet can place an air sac tube, which will usually relieve the breathing difficulty like magic! Air sac tubes can also save a bird that has a fungal lesion in the upper portion of the respiratory tract that is partially preventing normal breathing, for example. Air sac tubes cannot be left in place permanently, but they are useful to aid breathing until the problem can be resolved.
The heart rate and rhythm may be monitored with an ECG capable of registering high heart rates, and the monitor should have a freeze function for interpretation. An esophageal stethoscope may be slid into the esophagus of a bird, which is attached to a monitor and amplifier that allows the surgical team to listen to breathing sounds and the heart sounds. An ultrasonic Doppler flow apparatus may be attached to an area over the wing artery of a bird, allowing the surgeon to listen to an audible signal of arterial blood flow.