TOGA Therapeutic Oxygen for Gastrointestinal Atony

Abstract

Background and aims: Ileus, mechanical bowel obstruction, and acute colonic pseudo-obstruction are characterized by distension of the intestines with accumulated bowel gas. Current treatments are not completely satisfactory.

Methods: By manipulating the partial pressures of oxygen and nitrogen in the trapped air with a novel 6-hour treatment with 100% oxygen via nonrebreather mask, the bowel can be successfully decompressed, facilitating resolution of the underlying condition.

Results: A positive clinical response was seen in 7/8 [87.5%] patients after therapeutic oxygen for gastrointestinal atony. Maximal lumen diameter decreased by an average of 1.14 ± 0.87 cm [16%].

Conclusion: In this first clinical report of therapeutic oxygen for gastrointestinal atony, the provision of 100% oxygen via nonrebreather mask is a useful therapy. It decreased the diameter of the intestinal lumen and enhanced resolution of ileus, acute colonic pseudo-obstruction, and bowel obstruction. This is a low-morbidity, low-cost treatment of gastrointestinal luminal distension.ClinicalTrials.gov Identifier NCT03386136.st.

Keywords: Ileus; Ogilvie’s Syndrome; Oxygen; Small Bowel Obstruction; TOGA.

Figure 1

Schematic representation of an alveolus of the lung in a patient receiving 100% oxygen by nonrebreather mask. Essentially, all nitrogen has been flushed from the inspired gases. This creates a gradient between nitrogen dissolved in plasma and the alveolus. Nitrogen goes down its gradient into the alveolus and is vented into the atmosphere.

Figure 2

Cross-sectional image of a representative portion of the gut wall. The lumen of the bowel (top) contains predominantly atmospheric air. This is approximately 80% nitrogen. The gut wall is well perfused with capillaries in the submucosa. The plasma is essentially free of nitrogen. Nitrogen diffuses down its gradient, from the intestinal lumen to the capillary blood. This blood returns to the lungs and releases nitrogen into the alveolus.

Figure 3

Illustration of the principle of diffusion of molecules across a semipermeable membrane. In these containers, the left-side compartment is separated from the right-side compartment by a semipermeable membrane. In the lung/alveolus situation, a high concentration of nitrogen, indicated by the orange dots, leaves plasma for the alveolus. This will be vented to the atmosphere by respiration. In the gut, a high concentration of nitrogen goes down its gradient to the plasma perfusing the bowel wall. This nitrogen is expired, and the cycle repeats during TOGA therapy.

Figure 4

(A) There was a pre-TOGA treatment showing a small bowel diameter of 111 mm [normal ≤ 35 mm]. (B) After 6 hours of TOGA, the posttreatment diameter was 61 mm (55% of original diameter). There was a concomitant improvement in the patient’s symptoms.