Gastric ulceration and H. Pylori Flashcards
What are risk factors for the development of gastric ulcers?
- H. Pylori
- NSAID use
- Smoking
- Reflux of duodenal contents
- Delayed gastric emptying
- Stress
What is the difference between an ulcer and an erosion?
A break in the mucosal lining of the stomach or duodenum more than 5 mm in diameter, with depth to the submucosa. Ulcers smaller than this or without obvious depth are called erosions.
How do peptic ulcers occur?
Result from an imbalance between factors promoting mucosal damage (gastric acid, pepsin, Helicobacter pylori infection, non-steroidal anti-inflammatory drug use) and those mechanisms promoting gastroduodenal defense (prostaglandins, mucus, bicarbonate, mucosal blood flow).
What type of bacteria is H. Pylori?
Slow-growing spiral gram-negative bacteria
Where is h. pylori most commonly found?
Gastric antrum
How is H. Pylori protected from gastric acid?
By juxtamucosal mucous layer which traps bicarbonate secreted by antral cells, and ammonia produced by bacterial urease.
What enzyme does H. pylori possess which enables it to convert area to ammonium and chloride?
Urease
What results from infection with H. Pylori?
- Antral gastritis
- Peptic ulceration (duodenal and gastric)
- Gastric cancer
What are features of gastric ulcers?
Can be asymptomatic, but can have:
- Recurrent, burning epigastric pain - relieved by antacids
- Nausea
- Weight loss
- Symptoms of anaemia
What are features of duodenal ulcers?
Can be asymptomatic, or:
- Burning epigastric pain - relieved by antacids
- Weight loss
- Signs of anaemia
- Epigastric tenderness
What are risk factors for the development of duodenal ulcers?
- H. pylori
- Drugs - NSAID’s, Steroids, SSRI’s
- Increased gastric acid secretion
- Increased gastric emptying
- Smoking
Why does chronic antral gastritis cause increased gastric acid secretion?
Causes hypergastrinaemia due to gastrin release from antral G cells
What might back pain in someone with dyspeptic symtpoms, weight loss and anaemia suggest?
Penetration of a posterior ulcer
What investigations would you consider going in someone with suspected peptic ulcers?
- Blood tests - FBC, H. pylori serology, fasting gastrin levels
- Urea breath test
- H. Pylori stool antigen test
- Upper GI endoscopy
What is involved in the urea breath test for investigating H. Pylori?
Give the patient <span>13</span>C or 14C labelled urea -> Measurement of 13CO2 in the breath after ingestion (requires mass spectrometer). The test is sensitive (90%) and specific (96%)
What is important to tell people to do before performing Urea breath test?
- Stop antibiotics for 4 weeks prior
- Stop PPIs 2 weeks prior
What staining is used on biopsy samples for investigating for H. pylori?
Giemsa staining
How would you manage someone with confirmed H. Pylori?
Eradication Therapy - Triple therapy for 7 days
- Clarithromycin 500mg bd
-
Amoxycillin 1g bd (or Metronidazole 400mg bd)
- Tetracycline is given if penicillin allergy
- PPI: e.g. omeprazole 20mg bd
If someone was found to be negative for H. pylori as the cause of their peptic ulcer, how would you manage them?
Acid suppression alone
What would be your differential diagnosis for someone with features of peptic ulceration?
- Non-ulcer-dyspepsia
- Duodenal crohn’s
- TB
- Lymphoma
- Pancreatic cancer
What is important to exclude on endoscopy in someone with suspected peptic ulcer disease in older patients?
Gastric cancer
What are alarm symptoms of someone with gastritis?
- Anaemia
- Loss of weight
- Anorexia
- Recent onset
- Malaena/haematemesis
- Swallowing difficulty
What are complications of peptic ulceration?
- Haemorrhage
- Perforation
- Gastric outlet obstruction/Pyloric stenosis
What are features of gastric outlet obstruction?
- Vomiting - infrequent, projectile, large in volume, contains particles of previous meals.
- Succussion splash
