Vascular responsiveness in obstructed gut

Abstract

Multiorgan system failure due to hypotension and sepsis is an important cause of death in patients with bowel obstruction. We have investigated the pathophysiology of this entity in an animal model. After 5 days of bowel obstruction, blood flow in the superior mesenteric artery was measured with and without Pitressin and norepinephrine given in separate experiments. In controls, Pitressin in moderate dosages caused a substantial fall in gut blood flow, which was not seen in obstructed animals (blood flow reduction 52 percent vs. 11 percent in sham and obstructed animals respectively, P less than 0.01). Similarly, norepinephrine infusion had less of an effect on gut blood flow in obstructed animals (blood flow reduction 79 percent vs. 58 percent sham vs. obstructed animals (P less than 0.05). Thus, both agents had dose-related effects on gut blood flow, which was maintained at a higher level throughout the drug infusion periods in the bowel of obstructed animals, demonstrating that splanchnic flow is less responsive to vasoactive drug infusion under these experimental conditions. Because splanchnic vasoconstriction is an important feature of normal hemodynamic homeostasis, we suggest that these results may help explain some aspects of the pathophysiology of multiorgan failure caused or worsened by systemic hypotension seen in bowel obstruction.

Malignant bowel obstruction in advanced cancer patients: epidemiology, management, and factors influencing spontaneous resolution

“…This pharmacologic activity reduces hydroelectrolytic retention in the intestinal lumen, as well as gastric secretions, intestinal motility, biliary flow, splanchnic hypervascularization, and intestinal parietal edema. Furthermore, it increases the absorption of water and the production of intestinal mucous 52,53. Different studies on the effectiveness of octreotide at doses from 200–600 μg/day have shown a clear reduction in intestinal secretions, the eventual possibility of withdrawing the nasogastric tube, and a high grade of antiemetic and analgesic response with no relevant adverse effects 2,8,54–58.…”

Recent advances in malignant bowel obstruction: an interface of old and new

“…High portal levels of VIP cause hypersecretion and splanchnic vasodilatation, with consequent hyperemia and edema of the intestinal wall that leads to further fluid accumulation [10]. Splanchnic vasodilation ultimately may cause systemic hypotension, leading to multiorgan failure and potentially death [11]. Sepsis also can occur as a result of bacterial translocation through the bowel wall secondary to the increased endoluminal pressure, stasis, and intestinal ischemia (Fig.…”

Management of Treatment-Related Intermittent Partial Small Bowel Obstruction: The Use of Octreotide

“…3,4 Administration of octreotide, a synthetic analog of somatostatin, results in a reduction of gastric and intestinal secretions, a slowing of intestinal motility, and a reduction of splanchnic blood flow. 5 At the intracellular level, octreotide acts at the interstitial epithelium to decrease secretion of water, sodium, and chloride, and improve both ion and water absorption. 6 These effects may be attributed to the inhibition of vasoactive intestinal peptide, a gastrointestinal hormone known to have increased levels in patients with any form of bowel obstruction.…”