Lecture 9 - Gastric disease Flashcards
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
Acute ulcers
Develop due to acute gastritis
Chronic ulcers
Occurs at mucosal junctions where antrum meets body on the lesser curve
In duodenum where the antrum meets the small intestines
Structure of peptic ulcer
Normally less than 2cm
Base of ulcer is necrotic with granulation tissue
Muscularis mucosa replaced by scar tissue - pyloric stenosis causing vomiting blood
Consequences of peptic ulcer
Haematemesis Perforation causing peritonitis Fistula Erosion into liver or pancreas Haemorrhage of splenic artery Malignancy
Peptic ulcer symptoms
Epigastric pain - sometimes radiates to back
- following meals
- at night
- burning sensation
- Haematemesis
- Maleana
- Anaemia - blood loss
- Weight loss
- Early satiety
Management of peptic ulcers
Lifestyle modification - eat less Stop exacerbating medications e.g. NSAIDs Test for H pylori PPI Endoscopy
Tests for gastric pathology
Endoscopy - biopsy H pylori Urease breath test CXR - perforation of fundus Blood test FBC - anaemia
H2 blockers
Cimetidine
Ranitidine
Block histamine modulation so less HCL is secreted from parietal cells
PPI
Omeprazole
Zollinger Ellison syndrome
Non beta islet cell gastrin secreting tumour of the pancreas
Proliferation of parietal cells
Increases secretion of gastrin and HCL
Severe ulceration of stomach and small bowel
- abdominal pain
- diarrhoea
Stomach cancer
Presents late as large for symptoms to appear
- dysphagia
- loss of appetite and eight loss
- Maleana
- Nausea and vomiting
- Spread to virchow’s nodes (left supraclavicular)
Risk factors of stomach cancer
Male
H pylori
High salt intake - Japan
Smoking
