H pylori and gastric disease Flashcards
what structures make up the upper GI tract
oesophagus
stomach
what structures make up the lower GI tract
small intestine
large intestine - colon
functions of the stomach (7)
food storage initial digestive process acidic environment for defence secretion of gastric acid gut hormones intrinsic factor pepsin
what is dyspepsia?
it’s a group of symptoms
pain or discomfort in the upper abdomen
it occurs for 4 weeks
very common but most often no serious cause
give examples of some of the symptoms dyspepsia describes (8)
upper abdominal discomfort retrosternal pain anorexia nausea vomiting bloating reflux heartburn
what 2 main categories can dyspepsia be divided into?
functional
organic
Upper GI causes for the symptoms of dyspepsia (5)
GORD Peptic ulcer Gastritis Non ulcer dyspepsia Gastric cancer
Systemic diseases that cause symptoms of dyspepsia (3)
metabolic and cardiac disease
drugs
psychological
what bloods, drug and lifestyle changes would need to be done/made if a patient presented with dyspepsia?
FBC, ferritin, LFTs, U&Es, calcium, glucose, coeliac serology/serum IgA
drugs - NSAIDs, steroids, biphosphonates, Ca antagonist, nitrates
lifestyle - alcohol, diet, smoking, exercise, weight reduction
What does the term ‘ALARMS’ cover when looking at referral for endoscopy?
Anorexia
Loss of weight
Anaemia – iron deficiency
Recent onset >55 years or persistent despite treatment
Melaena/haematemesis (GI bleeding) or mass
Swallowing problems - dysphagia
what type of bacteria is helicobacter pylori (H. pylori)
gram negative
spiral shaped
microaerophilic
what % of the world population does H. Pylori infect?
50% usually acquired during childhood
H.pylori can only colonise in which type of mucosa?
gastric type mucosa
where does the H. pylori bacteria reside in the gastric mucosa
in the surface mucous layer - it does not penetrate the epithelial layer
what are the clinical outcomes of H. pylori infections? (7)
Most commonly -asymptomatic or chronic gastritis
15-20% chronic atrophic gastritis, intestinal metaplasia or gastric/ duodenal ulcer
<1% gastric cancer or MALT lymphoma
what is the clinical outcome of H.pylori infection dependent on? (3)
site of colonisation characteristics of bacteria host factors (e.g genetic susceptibility and other environmental factors like smoking)
what are some of H.pylori’s virulence factors
urease - allows it to colonise in acidic environment of the stomach
flagella - enables it to move and colonise elsewhere
adhesive toxins
common response to chronic H. pylori infection in the antral part of the stomach (pyloric end near bottom)
increased gastric acid
low risk of gastric cancer
common response to chronic H. pylori infection in the corpus part of the stomach (main bit)
decreased gastric acid gastric atrophy (inflamed mucosal lining for years)
often leads to gastric cancer
non invasive techniques to diagnose H. pylori infection (3)
serology - IgG against H. pylori
13/14 degrees urea breath test
stool antigen test - ELISA need to be off proton pump inhibitors for 2 weeks
invasive techniques to diagnose H. pylori infection (3)
histology - gastric biopsies stained for the bacteria or culture of the biopsy
rapid slide urease test (CLO) - detects urease enzyme of H. pylori
what are the majority of peptic ulcers caused by?
H. pylori
symptoms associated with peptic ulcers (7)
Epigastric pain
Nocturnal/hunger pain
Back pain
Nausea and occasionally vomiting
Weight loss and anorexia
Only sign may be epigastric tenderness
If the ulcer bleeds, patients may present with haematemesis and/or melaena, or anaemia
treatment for peptic ulcers caused by H. pylori?
eradication therapy to get rid of bacteria
antacid medication - proton pump inhibitors or H2 receptor antagonist
surgery only indicated in complicated peptic ulcer disease
how is H. pylori infection eradicated
triple therapy for 7 days
Clarithromycin
Amoxycillin
(Tetracycline is given if penicillin allergy)
PPI eg omeprazole
very effective
complications of a peptic ulcer (5)
Acute bleeding – melaena and haematemesis
Chronic bleeding – iron deficiency anaemia
Perforation
Fibrotic stricture (narrowing)
Gastric outlet obstruction – oedema or stricture
how is gastric outlet obstruction treated
endoscopic balloon dilatation
surgery
symptoms of gastric outlet obstruction
Vomiting – lacks bile, fermented foodstuffs
Early satiety, abdominal distension, weight loss, gastric splash
Dehydration and loss of H+ and Cl- in vomit
Metabolic alkalosis
Types of gastric tumour
MALT
GIST
what is the name of the hereditary condition that increases your chance of getting gastric cancer
Hereditary diffuse gastric cancer (HDGC)
what is the main tumour sepressor gene involved with gastric cancer
CDH-1 gene
