In any system of ether administration by inhalation, a percentage of ether vapor is added to the tidal respiratory air and is carried to the pulmonary alveoli during inspiration. On expiration, a part of the ether vapor is expired and wasted, the proportion of waste depending on the point in the respiratory tract to which the ether vapor has been delivered. The points of delivery of the ether vapor in inhalation anesthesia, arranged in order of their efficiency are: the bifurcation of the trachea, as in tracheal insufflation; the oropharynx, as in pharyngeal insufflation, and the nasal and oral orifices, as in the usual methods of anesthesia.
ADVANTAGES OF PHARYNGEAL INSUFFLATION ANESTHESIA
When compared with the delivery of ether vapor to other points in the respiratory tract, pharyngeal insufflation has manifest advantages. The introduction of the pharyngeal tube is a simple matter, takes little time and does not require a