MODERN endotracheal anesthesia is a technic in which the administration of an anesthetic may be facilitated and the patient benefited by an artificial extension of the tracheobronchial tree by means of a tube through which the patient's respiratory exchange takes place. Endotracheal tubes are made of materials such as rubber and plastic. When in place these tubes create a relatively nonobstructable channel through which the respiratory exchange occurs.
Basically, an endotracheal technic is one in which a tube is passed through the mouth (constituting an orotracheal intubation), through the nose (constituting a nasotracheal intubation) or through a tracheostomy opening (constituting a tracheostial intubation). Intubation may be performed under direct vision by the use of a laryngoscope or by the so-called "blind" technic, the tube being maneuvered through the glottis by skilful manipulations. Successful intubation requires considerable practice and a good knowledge of the structure and the functions of the upper
MAX S. SADOVE, WILLIAM H. CASSELS. ENDOTRACHEAL ANESTHESIA. Arch Surg. 1947;55(4):493–497. doi:10.1001/archsurg.1947.01230080501009