Venous air embolism in head and neck surgery.

Venous air embolism can occur under many circumstances, including head and neck surgery when the head is elevated. Embolized air obstructs the pulmonary outflow tract of the right ventricle or the pulmonary arterioles. Small volumes are tolerated or dispersed, but larger volumes can lead to severe physiologic changes. The Doppler precordial monitor is the most effective means of detection and should be used in major operations on the head and neck. Treatment methods are discussed and should be understood by all otolaryngologic surgeons.