5. Gastric clinical conditions

Question 1

what is GORD and how would a P present

Answer 1

Gastro-oesophageal reflux disease: reflux of stomach contents/acid into oesophagus causing ulceration of oesophageal mucosa (oesophagitis).
Is a result of:
- decreased tone of LOS
- delayed gastric emptying (raised intra-gastric pressure, e.g. due to obesity or pregnancy)
- hiatus hernia

Symptoms:

• heartburn
• cough
• sore throat
• dysphagia

Question 2

name 2 possible complications of GORD

Answer 2

1. strictures (causing dysphagia)
2. Barrett’s oesophagus: metaplasia of stratified squamous epithelium to columnar containing goblet cells, with 30-40x increased risk of developing adenocarcinoma

Question 3

describe the management of GORD

Answer 3

1. lifestyle changes
2. pharmacological: antacids, H2 antagonists, PPI
3. surgery (rare)

Question 4

what is acute gastritis, why does it occur and how does it present

Answer 4

Transient bouts of acute gastric mucosa inflammation, may involve: increased HCL secretion, reduced HCO3- production, reduced blood flow (… ischaemia) or direct injury to mucosa

Can be stimulated by:

1. NSAIDs (esp. aspirin)
2. heavy smoking or alcohol consumption
3. chemotherapy
4. bile reflux

Frequently asymptomatic but may have:

• epigastric pain
• nausea or vomiting
• mild to massive upper GI bleeds (can be fatal)

Question 5

what is chronic gastritis, what are the 2 main causes and how does it present

Answer 5

Chronic inflammation (lymphocytes and plasma cells) of gastric mucosa with progressive atrophy. May eventually progress to gastric carcinoma due to metaplasia and dysplasia.

2 basic aetiologies:

 1. H. pylori infection - involves immune resp. to bacteria, with MALT expansion. Asymptomatic or similar symptoms to acute gastritis.

 2. autoimmune gastritis - type II hypersensitivity reaction with autoantibody production against HK ATPase of parietal cells... decreased parietal cells... decreased production of:  - intrinsic factor (... inability to absorb vit B12... megaloblastic pernicious anaemia)  - HCL (... achlorydia) Causes symptoms of anaemia, glossitis, anorexia and neurological symptoms.

Question 6

name possible complications of chronic gastritis caused by H. pylori infection

Answer 6

peptic ulcers, adenocarcinoma, MALT lymphoma

Question 7

what is peptic ulcer disease and where does it most commonly occur. what are the main symptoms

Answer 7

Peptic ulcer = breach in gastric or duodenal mucosa that extends through muscularis mucosa.
Most common in:
1- early duodenum
2- lesser curvature of stomach

Main symptom: epigastric pain - burning/gnawing following meals, often at night

Serious symptoms: bleeding/anaemia, early satiety and weight loss

Question 8

name the causes of peptic ulcer disease, inc. an example of adenoma

Answer 8

1. mucosal injury, e.g. stomach acid, H. pylori infection, NSAIDs (inhibit prostaglandin synthesis necessary for mucosal defence)
2. massive physiological stress (e.g. burns, raised ICP) = STRESS ULCERATION
3. ZOLLINGER-ELLISON SYNDROME: gastrin-secreting gastrinoma (neuroendocrine tumour) resulting in increased gastric acid secretion by parietal cells

Question 9

name 2 possible serious complications of peptic ulcers

Answer 9

1. v. deep ulcers can erode into underlying blood vessels… rapid HAEMORRHAGE into GI tract
2. PERFORATION if ulcer erodes all the way through wall… peritonitis

Question 10

which blood vessels are at risk of erosion in peptic ulcer disease

Answer 10

L gastric a. (from gastric ulcer in lesser curve of stomach)

Gastroduodenal a. (from post. wall duodenal ulcer)

Question 11

how does H. pylori affect the gastric mucosa

Answer 11

1. releases cytotoxins… direct epithelial injury
2. enzyme expression: urease - converts urea to ammonia which is toxic to epithelial cells
3. promotes inflammatory resp. - self-injury
4. degrades mucus layer?

Question 12

whay type of bacterium is H. pylori, how is it spread and how does it survive in stomach

Answer 12

• GNB spread oral-oral or faecal-oral
• survival:
  1. produces urease: converts urea to ammonium (basic in solution)… increases local pH
  2. flagellated: good motility, lives in mucus layer/adheres to gastric epithelia

Question 13

how is H. pylori eradicated

Answer 13

triple therapy with PPI + clarithromycin + amoxicillin

Question 14

name 2 mechanisms for gastric acid secretion suppression

Answer 14

1. H2 blockers - block histamine Rs on parietal cells… decreased acid secretion
2. proton pump inhibitors (omeprazole) - block H+/K ATPase on parietal cells… decreased acid secretion