Does the bowel prevent the outward diffusion of gas from within the balloon of intestinal tubes?

The effect of submersion of balloons of intestinal decompression tubes inflated with different gases in water was studied and compared with similar studies in which the inflated balloons were exposed to air. The experiment indicated that there was very little or no difference in the speed of diffusion of the gases from within the balloons exposed to air or submerged in water. In reproducing in vivo conditions the inflated balloons were inserted within the intestinal tract of an hour-old autopsy specimen. The inflated balloon caused the bowel wall to be stretched tightly over it. We noted that the speed of diffusion of the gases out of the balloons was the same whether the bowel was empty or filled with intestinal secretions. There appeared to be very little difference between the speed of diffusion of gases out of the balloons within the bowel or those submerged in liquid or exposed to air. This experimental study clearly shows that if an intestinal decompression tube balloon becomes inflated as a result of carbon dioxide or hydrogen sulfide, the passage of a second intestinal tube to decompress the circumjacent bowel would rapidly result in the diffusion of the hydrogen sulfide or the carbon dioxide from within the balloon into the bowel. The speed of diffusion of the hydrogen sulfide is so fast that it is extremely doubtful whether this gas enters into the problem at all. The only possible influence this gas might have is suggested by our observations that balloons filled with hydrogen sulfide rapidly lost this gas in less than four hours. If then these balloons were permitted to lie exposed to the air, they took up some of the air. This diffusion of air into balloons formerly filled with hydrogen sulfide might constitute a real problem in intubation, or the presence of an air-filled Miller-Abbott balloon which could not be evacuated as a result of a knot in the tube might be quite serious for the patient. The reason for this is obvious from our observations that the air-filled balloons showed very little or no change in twenty-four hours. Some balloons filled with air were observed for four days and were then noted to show very little if any loss of air. When we recall that approximately 80 per cent of the air consists of nitrogen, a gas which is extremely slowly diffusible through a rubber membrane, it becomes obvious why this should be so. Once air has accumulated within the intestinal tube balloons many days of bowel decompression are required before any appreciable loss of air occurs from the balloon. The best treatment for this unusual accident is to prevent it by the use of a No. 18 French lumen tube and a safety valve vent as described in an earlier publication.1