A method for the direct observation of normal peristalsis in the stomach and intestines

When the abdomen is opened peristalsis ceases. Because of this fact all previous investigators have found difficulty in making observations directly upon the motility of the stomach and intestines. The peristalsis which has been seen differs considerably from that which the radiographs of Cannon have shown to be the normal movements.

Failure of peristalsis, as Meltzer especially has pointed out, is one of the characteristic and important phenomena of surgical shock. I have advanced the hypothesis 1 that the cause of shock is acapnia. By applying this theory to the problem of maintaining normal peristalsis after laparotomy, the following simple and effective method was devised. After the administration of a moderate dose of morphin, the animals (dogs of about 10 kilos) were anæsthetized with chloroform. So far as possible the hyperpnœa of the initial stage of anæsthesia was avoided. The abdomen was laid open the entire length of the mid line. The omentum was cut out, and the viscera moved sufficiently to bring into view the upper colon, lower ileum, and the greater curvature of the stomach from the pre-antral groove to the pylorus. A sheet of transparent celluloid was inserted under the body wall and over the viscera; and the air in the space back of this window was washed out with a stream of carbon dioxide gas. To the trachea was attached a tube 15 mm. in diameter and 2 meters in length. Blood gas analyses showed that the blood-gases were thus maintained normal,—not asphyxial in respect either to the oxygen or carbon dioxide contents. When the stomach was distended with air, and the large intestine and lower ileum with bread mush, movements in these three parts of the alimentary canal were seen identical with those shown by the radiographs of Cannon. In the stomach a deep constriction developed at the pre-antral groove every 15 seconds and moved toward the pylorus where it disappeared as its successor was developing. In the colon there was active anti-peristalsis. In the ileum vigorous rhythmic segmentation was seen.