HYPERBARIC OXYGEN AND THE GASTROINTESTINAL TRACT

Rachmilewitz, D. et al. "Hyperbaric oxygen: a novel modality to ameliorate experimental colitis." Gut, 1998; 43(4): 512-8.
BACKGROUND: Hyperbaric oxygen (HBO) has been suggested to be beneficial in inflammatory bowel disease but the mechanisms responsible for its therapeutic effects have not been elucidated. AIM: To assess the effect of HBO treatment on colonic damage in two models of experimental colitis, and to examine whether this effect is mediated by modulation of NO synthesis. METHODS: Colitis was induced by either flushing the colon with 2 ml 5% acetic acid or intracolonic administration of 30 mg trinitrobenzenesulphonic acid (TNB) dissolved in 0.25 ml 50% ethanol. Rats were exposed to HBO (100% oxygen at 2.4 atmosphere absolute) for one hour twice on the day of colitis induction and once daily thereafter. Control rats were treated only with acetic acid or TNB. Rats were killed 24 hours after acetic acid administration or one and seven days after TNB treatment. The colon was isolated, washed, and weighed, the lesion area was measured, and mucosal scrapings were processed for determination of myeloperoxidase (MPO) and NO synthase (NOS) activities, prostaglandin E2 (PGE2) and leukotriene B4 (LTB4) generation. RESULTS: In control rats exposed for seven days to HBO, colonic NOS activity was significantly decreased by 61%, compared with its activity in untreated rats (2.93 (0.17) nmol/g/min). HBO significantly reduced by 51 and 62% the extent of injury induced by acetic acid and TNB respectively. The protection provided by HBO was accompanied by a significant decrease in colonic weight, PGE2 generation, MPO, and NOS activities. In acetic acid colitis, LTB4 generation was also significantly decreased. CONCLUSIONS: (1) HBO effectively decreases colitis induced by acetic acid and TNB. (2) The decreased NOS activity induced by HBO suggests that reduction in NO generation may be among the mechanisms responsible for the anti-inflammatory effect of HBO. (3) HBO may be considered in the treatment of patients with refractory inflammatory bowel disease.

Favre, C. et al. "Hyperbaric oxygen therapy in a case of post-total body irradiation colitis." Bone Marrow Transplant, 1998, Mar; 21(5): 519-20.
We report a 21-year-old man who experienced symptoms of colitis following autologous TBI-conditioned PBSC transplantation, which persisted despite conventional treatment. Abdominal echography showed a thickened, stratified wall of the cecum, of the right colon and of part of the transverse colon. Hyperbaric oxygen therapy (20 sessions of 100% oxygen inhalation at 2.5 bar for 120 min in a hyperbaric chamber) achieved a prompt clinical recovery as well as complete disappearance of the ultrasound abnormalities.

Andresen, S.J. et al. "Pneumatosis cystoids intestinalis." Tidsskr Nor Laegeforen, 1999, 119(12): 1756-7. (article in Norwegian)
Patients with free intraperitoneal air usually undergo emergency surgery. Some of these patients will have no identifiable perforation, for instance those with pneumatosis cystoides intestinalis. This is a rare condition characterized by multiple intramural gas cysts in the gastrointestinal tract. The most common symptoms are meteorism, excessive flatulence, diarrhoea, abdominal pain, passage of mucus per rectum, or rectal bleeding.

A case of pneumatosis cystoides intestinalsis is described. Plain abdominal radiographs showed distended bowel with free intraperitoneal air and intramural gas collections. At laparotomy, multiple intramural cysts were found, but no perforation or obstruction. The symptoms resolved after laparotomy, and the patient was discharged after a few days. The aetiology and pathogenesis of pneumatosis cystoides intestinalis are unknown, although deficient hydrogen metabolism and gas-forming bacteria that penetrate the mucosal barrier may be involved. If needed, hyperbaric oxygen therapy is the treatment of choice. Surgery is indicated only in fulminant cases.

Paw, H.G. et al. "Pneumatosis cystoids intestinalis confined to the small intestine treated with hyperbaric oxygen." Undersea Hyperbaric Medicine, 1996, 23(2): 115-7.
Pneumatosis cystoides intestinalis is a rare disease characterized by the presence of multiple intramural gas-filled cysts in the gastrointestinal tract. The etiology remains unknown, but the disease can present with profound disturbances of bowel function. We report the successful management of pneumatosis cystoides intestinalis of the small intestine with the use of hyperbaric oxygen.

Nordkild, P. et al. "Spontaneous clostridial myonecrosis. A collective review and report of a case." Ann Chir Gynaecol, 1986; 75(5): 274-9.
A collected series from the English literature up to 1984 of spontaneous clostridial myonecrosis (SCM) is presented in order to reveal possible common denominators. SCM was associated with malignancy (colonic cancer and leukaemia), diabetes, and injections in descending order. C. perfringens was isolated in more than 70% of the cases followed by C. septicum in 27 and C. novyi in 7%. The pathogenesis is still speculative but is thought to be due to bacteraemia especially from the gastrointestinal tract, due to growth of dormant spores in tissue following antecedent trauma or as an infection descending along the ilio-psoas sheath from a gastrointestinal focus. The symptoms are pain in an oedematous, discoloured, crepitant area with haemorhagic bullae and often shock. The diagnosis is based on the clinical findings and Gram-positive rods in the exudate. Treatment instituted promptly constitutes of surgical debridement, antibiotics and hyperbaric oxygen. The prognosis of SCM is worse than for other cases of clostridial myonecrosis and survival was in this collected series only 19%.