Although the pathophysiology of SRES is not fully understood, gastric acid and pepsin appear to play a dominant role in the development of the gastroduodenal lesions characteristic of this entity. Both increased stress and head injury are associated with increased gastrin-mediated acid production (Beejay and Wolfe, 2000). As with other acid-related disorders, SRES appears to result from an imbalance between aggressive and defensive factors. Normal mechanisms of gastric mucosal integrity depend on an intact microcirculation, which ensures an adequate supply of nutrients to the mucosa and, in conjunction with the mucous layer, neutralizes hydrogen ions and other locally noxious agents. Mucosal ischemia appears to be the critical factor in the pathogenesis of SRES. Critical illness is commonly associated with hypovolemia, the release of proinflammatory cytokines, and increased cathecolamines production, which in turn lead to splanchnic hypoperfusion (Fisher et al, 1995). Reductions in mucosal blood flow promote intracellular acidosis, the release of nitric oxide, the production of oxygen-derived free radicals, increased cell permeability, a decrease in the synthesis of prostaglandins, and diminished acid buffering capacity. In addition, mucosal ischemia leads to decreased mucus and bicarbonate secretion and defects in epithelial cell restitution after injury, all of which contribute to the back-diffusion of hydrogen ions into the gastroduodenal mucosa. Back-diffusion of acid is thought to play a central role in the disruption of the surface epithelial barrier, which may later progress to erosive lesions resulting in clinically significant hemorrhage. Small amounts of luminal acid may be sufficient to induce gastroduodenal damage, and SRES can occur even when gastric acid secretion is diminished.

Constipation Prescription

Constipation Prescription

Did you ever think feeling angry and irritable could be a symptom of constipation? A horrible fullness and pressing sharp pains against the bladders can’t help but affect your mood. Sometimes you just want everyone to leave you alone and sleep to escape the pain. It is virtually impossible to be constipated and keep a sunny disposition. Follow the steps in this guide to alleviate constipation and lead a happier healthy life.

Get My Free Ebook

Post a comment