Gastric Disorders B&B Flashcards
state 4 common causes of acute gastritis
- NSAIDs: block prostaglandin production (inhibits H+ secretion)
- alcohol: direct mucosal damage
- chemotherapy: inhibits epithelial cell replication
- H. pylori
which patients get Curling’s Ulcers?
burn patients
loss of skin = loss of fluids/dehydration —> decreased plasma volume/ hypotension to stomach —> mucosal damage
give PPP
what is the cause of Cushing’s Ulcer?
increased intracranial pressure (tumor, hemorrhage) causes vagal stimulation —> ACh causes excess acid production
high ICP —> high vagal tone —> high ACh —> high H+ secretion
give PPP
what is the mechanism of stress ulcers?
shock/sepsis/trauma causes decreased mucosal perfusion —> loss of protective barrier of mucus/bicarb
common in ICU patients, PPP given prophylactically (pantoprazole, omeprazole)
name 2 proton pump inhibitors often given prophylactically to ICU patients to prevent stress ulcers (due to hypotension)
- pantoprazole
- omeprazole
and others, obvs
Type A vs Type B chronic gastritis
Type A = autoimmune (pernicious anemia)
Type B = H. pylori
describe the pathology of autoimmune gastritis
aka pernicious anemia: autoimmune destruction of gastric parietal cells —> loss of intrinsic factor secretion, needed for B12 absorption in the terminal ileum
inflammation occurs in body and fundus of stomach
intrinsic factor is needed for B12 absorption in the ______
terminal ilium
where does inflammation occur in autoimmune gastritis, and with what cancer is this associated?
aka pernicious anemia: autoimmune destruction of gastric parietal cells —> loss of intrinsic factor secretion, needed for B12 absorption in the terminal ileum
chronic inflammation occurs in gastric body/ fundus, and associated with gastric adenocarcinoma
with which HLA genes is autoimmune gastritis associated?
aka pernicious anemia: autoimmune destruction of gastric parietal cells —> loss of intrinsic factor secretion, needed for B12 absorption in the terminal ileum
associated with HLA-DR antigens and more common in women
where do ulcers caused by H. pylori occur? (specifically)
pyloric antrum of stomach - distal end close to duodenum
does not invade mucosa, sits ontop of epithelial cells and secretes urease to survive low pH
which 2 malignancies are associated with H. pylori?
- gastric adenocarcinoma
- MALT lymphoma (B-cell)
how does the urea breath test work for diagnosing H. pylori infection?
patients swallow radio-labeled urea
when H. pylori secretes urease, it splits urea to produce isotope-labeled CO2, which is detected in exhaled breath
what is the triple therapy for H. pylori infection?
- proton pump inhibitor (PPP)
- clarithromycin
- amoxicillin/ metronidazole
testing often repeated to confirm eradication
Zollinger-Ellison Syndrome
rare cause of duodenal ulcers, due to gastrin secreting tumor
cause development of multiple ulcers in duodenum, may also develop ulcers in distal duodenum or jejunum
when is pain caused by duodenal ulcers worse, and why is this?
worst at night because stomach is empty
improve with meals because stimulated bicarb secretion (secretin/VIP in pancreas; Brunner’s glands in duodenum) raises pH
what would cause hypertrophy of Brunner’s Glands?
Brunner’s glands: found in submucosa of duodenum, secrete alkaline fluid to protect from acidic stomach chyme
hypertrophy occurs in peptic ulcer disease
upper GI bleeding is more common with duodenal ulcers that are [anterior/posterior]
complications more common with posterior duodenal ulcers because the gastroduodenal artery and pancreas are located at the posterior of the duodenum
—> upper GI bleeding, pancreatitis, perforation
upper GI bleeding is that which occurs above…
… the ligament of Treitz - attaches broadly to the duodenum, then attaches like an apron to the back of the abdominal wall
suspends the distal duodenum
how can stool color be used to distinguish upper vs lower GI bleeding?
upper GI bleeding causes dark/“tarry” stools because blood is exposed to acid and bacteria on the way out
lower GI bleeding is bright red (hematochezia)
where (anatomically) do gastric ulcers most commonly occur, and which artery can they injure?
less common than duodenal ulcers, usually occur in lesser curvature - rupture can cause bleeding from the left gastric artery
pain is worse with meals due to stimulated acid release
when is the pain worst with gastric ulcers, and why?
usually occur in lesser curvature
pain is worse with meals due to stimulated acid release
contrast the 2 types of gastric adenocarcinoma (95% of gastric carcinomas)
- intestinal: appears as large ulcer with irregular margins (also occurs in lesser curvature), results from intestinal metaplasia, associated with older men, smoking/alcohol, nitrosamines (smoked meats), Type A blood
- diffuse: less common, few established risk factors, entire stomach is involved
what is the gross and histological appearance of the intestinal type of gastric adenocarcinoma?
gross: large ulcer with irregular margins
histological: similar to colonic adenocarcinoma, results from intestinal metaplasia —> goblet cells, common in lesser curvature (where ulcers occur)
