This includes the investigation of the size and capacity of the organ, of its secretory and motor functions, and of the microscopical characters of its contents.
Tn addition to the general information derived from inspection it is necessary to have recourse to some special method whereby the size and location of the viscus may be accurately determined. Of the various methods in vogue, only those of auscultatory percussion, artificial inflation, and electric illumination require special mention.
This is performed in the following manner. Half a pint or more of effervescent soda-water is administered to the patient, with the view of procuring moderate distension of the stomach, and he is then directed to lie upon his back with the shoulders and head slightly raised. The examiner places the end of a stethoscope over the epigastrium, and then makes a series of sharp taps with the index finger of the right hand upon the abdominal wall along lines which radiate from the point of auscultation. As long as percussion is made over a spot where the stomach is in contact with the parietes of the abdomen the shock conveyed to the ear is of the same intensity; but immediately the finger travels off the gastric area the sound becomes faint and toneless. The points at which this change takes place are marked on the skin with a blue pencil, and the investigation is continued in all directions until the entire outline of the viscus is mapped out on the skin. This method is not only very accurate in its results, but is also easy to perform, and does not entail any discomfort to the patient. The only point which requires special attention is the application of the stethoscope immediately over the stomach.
This may be performed in two ways : either by the administration of chemical substances which generate gas when mixed together, or by forcibly pumping air into the organ. Inflation by carbon dioxide is a very old procedure (Wagner, 1869), which has recently been again brought into fashion by Biegel and Boas. Forty to sixty grains of bicarbonate of sodium and thirty to forty grains of tartaric acid are each dissolved in about eight ounces of water contained in separate glasses. The patient first drinks the acid, and then the alkaline solution, and is directed not to eructate any gas. The interaction of the two substances causes a rapid evolution of carbon dioxide, which distends the stomach to its utmost capacity and causes its outlines to become visible upon inspection of the abdomen. In the second method a soft tube is introduced into the stomach, and air is either pumped in by a hand bellows or blown in by the mouth until the organ is sufficiently distended to be apparent. Gaseous inflation of the stomach, although often a valuable aid in diagnosis, is not devoid of danger, as the upward displacement of the diaphragm which it occasions is apt to embarrass the action of the heart and to produce syncope. When the pylorus is incompetent and the walls of the stomach rigidly infiltrated, the gas often escapes into the intestine without producing distension of the viscus. Hemmeter prefers to use a rubber bag made in the shape of the stomach, which is introduced at the end of a soft tube and can be inflated in position. By allowing the air to escape into a spirometer the capacity of the stomach may also be gauged.
Einhorn has invented a method of illuminating the stomach by means of a small electric lamp fixed in the eye of a tube. After the organ has been washed out the patient drinks a pint of water and the instrument is passed into the stomach. The viscus transmits the light through the abdominal walls and becomes visible as a red zone. According to our experience gastrodiaphany is of very little value, although it is highly spoken of by some American writers.