Is There a Relationship between Gastric Mucosal Blood Flow and Stress Lesions in Hemorrhagic Shock?

Abstract

The relationship between gastric mucosal blood flow and stress lesion formation during hemorrhagic shock was studied in anesthetized dogs. Shock was induced by graded arterial bleeding. Blood flow was measured by means of the radioactive microsphere technique. Mapping of blood flow was achieved by measuring the microsphere accumulation in mucosal and muscle segments of 1–2 cm side length of the entire stomach. To produce a varying incidence of lesions the metabolic acidosis of shock was either fully corrected by intravenous sodium bicarbonate (n = 5), partially corrected (n = 4) or left uncorrected (n = 3). Mucosal lesions developed more frequently in dogs without correction than in dogs with partial correction or full correction. In 4 dogs not subjected to shock, no mucosal lesions were observed at the end of the experiments. Mucosal blood flow varied from segment to segment by a factor of up to 20, but individual segments tended to maintain their relative flow values during shock. Correction of metabolic acidosis did not significantly affect blood flow. Likewise, flow was similar in segments with and without lesions. Therefore, low regional blood flow did not predispose to the development of lesions and high flow did not prevent them. We conclude that focal mucosal ischemia alone does not lead to stress lesion formation during hemorrhagic shock.

Induction of Anacidity Restores Gastric Aminopyrine Clearance in Canine Hemorrhagic Shock

“…Controlled ar terial bleeding with subsequent systemic hy potension was used to create a predictable fall of gastric mucosal blood flow. The devel opment of gross mucosal lesions was pre vented by the administration of intravenous sodium bicarbonate [16,17], An equilibra tion period was allowed to establish steadystate conditions of aminopyrine. A steep pH gradient between the mucosa and the gastric lumen was maintained by a high-rate perfu sion of the stomachs with 0.1 N HC1.…”

“…During the experiment, sufficient amounts of intravenous so dium bicarbonate were administered to maintain the arterial pH above 7.30. This procedure prevented shock-induced, gross mucosal damage and bleeding [16,17].…”

Effect of psychogenic stress on gastrointestinal function

“…Nowadays however, the known efficacy of locally acting drugs (Hz histamine antagonists, H+/K+ pump inhibitors, antibiotics) has hampered deeper investigation into the psychogenic nature of the disease and its psychological therapy. Even so, stress-induced gastric ulceration is still a matter of concern in the intensive care patient, especially in cases of hypovolemic or cardiac shock, in which disproportionate ischaemia in the gastric mucosa ultimately causes ulceration (44,71). On the other hand, stress is also notorious for its influence on the motility and general function of the intestine, the best example of which is irritable bowel syndrome, although this area has received considerably less attention on the part of investigators.…”