Lecture 9 - Gastric disease Flashcards
(36 cards)
Dyspepsia
Indigestion
Upper GIT symptoms:
- abdominal pain
- heartburn
- acid reflux
- nausea and vomiting
Functional dyspepsia diagnosis of exclusion
GORD
Gastric-oesophageal reflux disease
Causes:
- Increased intra-abdominal pressure
- Damage to LOS
Symptoms:
- chest pain
- acid taste in mouth
- cough
Consequences:
- Nothing
- Oesophagitis
- Strictures - vomit
- Barret’s oesophagus
Lower oesophageal sphincter
- Lower 4cm of oesophagus is made of smooth muscle
- Right diaphragmatic crus tightens
- Oblique angle of entry by the oesophagus into the stomach
- When abdominal pressure increases the lumen collapses
LOS at rest
Contracted
Highest pressure at night
Treatment of GORD
Lifestyle modification - not eating before sleeping
- eating slower and less more often
Pharmacological:
Antacids
H2 antagonists - less H+ release
PPI - proton pump inhibitors
Surgery:
Fundoplication
Hiatal hernias
Small section of stomach through the diaphragm to thorax
GORD oesophagitis more common in people with hiatal hernias
- oesophagus higher up in thorax decreases basal constriction
- Reduces the normal increase in tone when straining
- Retention of gastric fluid in hernial sac
- Loss of support from the LOS
Gastritis
Inflammation of the gastric mucosal lining the stomach
Can be acute or chronic
Symptoms:
- epigastric pain
- nausea and vomiting
- bleeding
- asymptomatic
Severe gastritis symptoms
Mucosal erosion Ulceration Haemorrhage Melena Haematemesis
Acute gastritis
Acute inflammatory response of the mucosal lining due to:
- NSAIDs - decrease prostaglandins
- Excessive alcohol - dissolves mucosal lining
- Chemotherapy - Kills rapidly dividing epithelial cells
- Bile reflux - irritant
Damaged epithelium and decreased mucous production
Therefore:
- Neutrophil invasion
- Vasodilation
- mucosal oedema
Gastropathy
Cell injury and regeneration with no neutrophils present
Causese: - NSAIDs - Excessive alcohol _ Bile - Stress induced injury - Mucosal erosion - ulcers or lesions
Symptoms and treatment of acute gastritis
- Abdominal pain
- Nausea and vomiting
- Occasional bleeding can be fatal due to hypovalaemia
Treatment:
- Remove irritant
Chronic gastritis
Causes:
- Helicobacter pylori (most common)
- Autoimmune
- Chronic use of alcohol, NSAIDs and bile reflux
H pylori
- Inhibition of gastric bicarbonate transporters by ammonium ions
- Can be asymptomatic or symptoms similar to acute gastritis
- symptoms can develop due to peptic ulcers, adenocarcinoma or MALT lymphoma
- less severe but more persistant
Autoimmune cause of chronic gastrits
Immune destruction of parietal cells in the body of the stomach
- Pernicious anaemia
- Less HCL secreted causing increased gastrin release as decreased somatostatin release and decreased iron absorption
- Less intrinsic factor therefore less absorption of vit B12
- Symptoms of anaemia
- Glossitis
- Anorexia
- Neurological symptoms due to Vit B12 deficiency
H pylori organism
Helix shaped (spiral)
Gram negative
Microaerophillic - requires low O2 to survive
Adhesins - resistance to peristalsis as adhered to foveolar cells
- Urease - neutralises acid
- Releases cytotoxins - causes ulcers and cancer
- Flagella - motile
Urease
Produces ammonium from urea
Increases local pH
H pylori in antrum
Most common
- Increased gastrin secretion due to decreased D cell activity so less somatostain released
- Parietal cell hyperplasia and over stimulation
- Increased acid production and peptic ulcers
- Duodenal epithelial metaplasia, colonisation and ulceration
H pylori in body
Atrophy
Gastric ulcers not due to acid
Intestinal metaplasia, dysplasia and cancer
- Parietal mass and decreased acid secretion causing hypergastrinaemia
- If in antrum and body = ASYMPTOMATIC
H pylori diagnosis
Urea breath tests to detect CO2
Gastric endoscopy and biopsy
Stool antigen test
Treatment H pylori
Proton pump inhibitor
Amoxicillin
+ clarithropmycin or metronidazole
Difference between chronic and acute gastritis
Acute:
- surface epithelial damage
- regenerative hyperplasia
- vasodilation
- neutrophils
Chronic:
- Lymphocytes
- glandular atrophy
- Lamina propria fibrosis
- Metaplasia
Peptic ulcer disease
Defect in the gastric or duodenal mucosa extending through the muscularis mucosa
Most common in proximal 1/3rd of duodenum, lesser curve and antrum
Pathogenesis of peptic ulcer disease
- Defect in body’s defences against acid
- Rapid gastric emptying causes inadequate acid neutralisation causing duodenal ulcers
Causes of peptic ulcers
H pylori
NSAIDs
Smoking - relapse of ulcer disease
Stress - extensive burns
