This section is from the book "Practical Dietetics With Special Reference To Diet In Disease", by William Gilman Thompson. Also available from Amazon: Practical Dietetics with Special Reference to Diet in Disease.
When an anaesthetic, such as ether or chloroform, is to be given, care should be exercised that the stomach is empty, otherwise vomiting is apt to occur at a critical moment when the patient is weak, and, being unconscious, the natural reflexes of the process, including the closure of the epiglottis, are not well carried out, and food is very easily drawn into the trachea and excites serious, if not fatal, choking. For this reason the patient is usually prepared for the anaesthetic by giving a light and easily digested breakfast, consisting solely of milk with, perhaps, a little farinaceous food, or a cup of coffee and a roll, and three or four hours later the anaesthetic may be administered with safety.
Feeble patients sometimes require an ounce of brandy or whisky half an hour before the operation - long enough before for it to become absorbed.
It is never desirable to give an anaesthetic within three hours after the ingestion of a full meal. It impedes anaesthetisation, besides causing the danger of vomiting and choking. In many cases it is better to allow five or six hours to intervene. In an emergency where an accident occurring shortly after a heavy meal requires the immediate use of anaesthesia, it may be well to give an emetic first for the purpose of completely unloading the stomach while the patient is conscious.
The instances of fatal choking from vomiting and aspirating food into the larynx are fortunately rare, as they are preventable, but they are by no means unknown. Since their occurrence is almost always due to negligence on the part of the anaesthetiser for not observing proper precautions, they are inexcusable. Ether, by some specific action, is more likely than chloroform to prove irritating and excite vomiting while being inhaled. When retching is violent it may be sometimes overcome by "crowding" the anaesthetic - that is, by causing it to be inhaled more energetically for a moment, until reflex irritation is overcome.