Diffusion of xenon and nitrous oxide into the bowel

Background: Nitrous oxide diffuses easily from blood into air filled spaces. Xenon is also a relatively insoluble gas, like nitrous oxide. Therefore, the authors measured xenon diffusion into obstructed bowel segments during xenon anesthesia and compared this with nitrous oxide and nitrogen diffusion. Methods: Twenty-one pentobarbital-anesthetized pigs were randomly assigned to three groups to receive either xenon-oxygen, nitrous oxide-oxygen, or nitrogen-oxygen (75%-25%, respectively. In each animal, four bo Fc el segments of 15-cm length were Isolated. A pressure-measuring catheter was inserted into the lumen, and 30 ml of room air was injected into the segments, Anesthesia with the selected gas mixture was performed for 4 h, Pressure in the segments was measured continuously. The volume of gaseous bowel content was measured on completion of the study. Results: The median volume of bowel gas in animals breathing nitrous oxide was 88.0 ml as compared with 39.0 ml with xenon anesthesia and 21.5 ml in the nitrogen-oxygen group. After 4 h of anesthesia, thr intraluminal pressures in the nitrous oxide group were found to be significantly greater than in the control group and in the xenon group. Conclusions: The amount of diffused gas was significantly lower during xenon anesthesia than with nitrous oxide anesthesia hut greater than with controls. Blood solubility carl therefore be regarded as an important factor influencing gas diffusion into air filled cavities,