Non-neoplastic Diseases Of The Stomach Flashcards
Gastritis
Results from mucosal injury
Can be acute or gastropathy
- acute = neutrophils present
- no inflammatory cells w/ injury = gastropathy
Most common causes are NSAIDS, alcohol, bile, stress induced injury, H. Pylori infections, chronic alcohol or radiation therapy
Can be asymptomatic or show:
- pain
- nausea
- vomiting
- hematemesis/ bloody stool (severe only)
What is the pH of gastric lumen?
Close to 1
Epithelial cells are protected usually due to secretion of bicarbonate ions
NSAIDs affect on gastritis
Inhibit COX-1/2
- decrease prostaglandins E2/I2
- these prostaglandins help induce bicarbonate and mucus secretions
How does H. Pylori cause gastritis
Secrete urease enzymes which inhibitors gastric bicarbonate transporters
What is stress-related gastric injuries?
Patients in severe trauma, extensive burns or major surgery
- 75% of critically ill patients develop endoscopically visible gastric lesions within 3 days
Stress vs curling vs Cushing ulcers
Stress ulcers = affect critical ill patients with shock/sepsis/trauma that can be anywhere
- most common cause is due to local ischemia
Curling ulcers = severe burns/trauma in the proximal duodenum
Cushing ulcers = intracranial disease that arise in stomach, duodenum or esophagus
- very high incidence of perforation
- vagal nuclei hyperstimulated = hypersecretion of acid
What are the difference between stress-related mucosal disease and peptic ulcers
Stress-related = multiple small and are found in numbers usually. Also can be anywhere in the stomach
Peptic ulcers = usually not multiple and are larger. Also only seen in the body of the stomach usually
What specific type of hematemesis is associated with Peptic ulcers
Coffee-ground hematemesis
What is the most common cause of chronic gastritis?
Helicobacter pylori
***Next most common cause is autoimmune disease and chronic NSAID use
Difference between chronic gastritis and acute gastritis symptoms
Chronic gastritis
- less severe
- very unlikely to see hematemesis
- upper abdominal discomfort and nausea are common
Acute gastritis
- more severe
- more likely to see hematemesis
Pathogenesis behind H. Pylori
Increased acid production in the antrum of the stomach
In chronic presence, reduces parietal cell mass and acid secretion. Also results in intestinal metaplasia
- all oft. His increases risk of gastric cancer
What are the virulence factors of H. Pylori
Flagella = allows for motility
Urease = elevates pH via ammonia production around H. Pylori to protect the organism
Adhesins = enhances bacterial adherence to surface cells
Toxins = Cytotoxin-associated gene A
Autoimmune gastritis
Accounts for less than 10% of chronic gastritis
- spares antrum usually but always presents with hypergastrinemia
Characteristics:
- antibodies in parietal cells and intrinsic factor that can be detected in serum and gastric secretions. (Causes reduction in acid and intrinsic factor levels)
- reduced serum pepsinogen 1 levels
- impaired gastric acid secretion
- astral endocrine (G) cell hyperplasia
(low acid levels = hypergastrinemia) - vitamin B12 deficiency leading to pernicious megaloblastic anemia
(No intrinsic factor = low B12)
Clincial features of autoimmune gastritis
Usually 60 yrs old and slight female predominance
- not linked to HLA alleles
Always shows parietal cells/intrinsic factor loss, but only some patients develop pernicious anemia
- always a decrease in acid
- always a increases in gastrin
- always G cell hypertrophy
What are the three most important complications of chronic gastritis?
1) peptic ulcer disease
2) mucosal atrophy and intestinal metaplasia
3) dysplasia
