H. Pylori & Gastric Disease Flashcards

1
Q

What is Heliobacter Pylori?

A

A gram -ve, spiral shaped, microaerophilic, flagellated bacterium carried by around 50% of the worlds population

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2
Q

Where does Heliobacter Pylori colonise?

A

Gastric mucosa

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3
Q

How does Heliobacter Pylori cause a problem?

A

Ammonia and other chemicals

Damages epithelial lining

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4
Q

What does a Heliobacter Pylori cause?

A

Chronic gastritis leading to:
- In most people no significant disease

  • If predominant in the body -> Loss of acid, gastric atrophy and finally gastric cancer
  • If predominantly in the antrum -> Rise in acid -> Duodenal ulcers
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5
Q

What determines the outcome of a Heliobacter Pylori infection?

A
  • Site
  • Environmental factors e.g. smoking
  • Genetic susceptibility
  • Bug characteristics (virulence factors)
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6
Q

Define virulence factors?

A

Molecules produced by certain strains of a micro organism which give it an advantage at colonising or harming the host.

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7
Q

In what ways can we diagnose Heliobacter Pylori infection?

A

Non-Invasive:

  • Stool Antigen Test (ELISA)
  • Urea Breath Test
  • Serology (IgG test)

Invasive (by Upper GI endoscopy):

  • Staining of gastric biopsy
  • Culture of biopsy
  • Rapid slide urease test
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8
Q

Explain the rapid slide urease test?

A

Biopsy of mucosa isplaced in a medium with urea and a pH indicator

> Urease converts urea to ammonia and CO2
pH rises
Indicator changes colour

Urease is an enzyme produced by Heliobacter Pylori

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9
Q

Explain the Urea breath test?

A
  • Urea tagged with an unusual isotope of carbon is breathed in
  • Bacteria converts to ammonia + CO2
  • Unusual isotope of carbon detected in breathed out CO2
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10
Q

What is the best invasive vs non-invasive way of detecting Heliobacter Pylori?

A

Stool Antigen Test (ELISA)

Rapid slide Urease Test

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11
Q

How do we eradicate a Heliobacter Pylori infection?

A

7 days of triple therapy:

  • Clarithromycin
  • Amoxicillin (tetracycline if penicillin allergic)
  • A Proton Pump Inhibitor (PPI) e.g. Omeprazole

Further 2nd line protocols should this fail

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12
Q

Define Dyspepsia?

A

Also known as indigestion.

A condition of impaired digestion causing symptoms such as:
- Upper abdominal pain/discomfort
- Anorexia
- Bloating
- Nausea / Vomiting
- Fullness and early satiety
- Heartburn
Retrosternal pain
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13
Q

How common is dyspepsia?

A

Around 80% of people get it occasionally with no serious underlying disease

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14
Q

Define a functional disorder?

A

One which impairs normal function of the gut without any detectable pathology.

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15
Q

Define an organic disorder:

A

Any disease in which there is detectable pathology. Either micro or macroscopic

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16
Q

Give some examples o dyspepsia causing conditions and whether they are functional or organic?

A

Functional:

  • Psychological (psychological factors are very important in many functional disorders)
  • Non-ulcer Dyspepsia
  • IBS
  • Drugs

Organic:

  • Peptic Ulcer
  • Gastritis
  • Gastric Cancer
  • Coeliac Disease
  • Colonic Cancer
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17
Q

When would an upper GI endoscopy be indicated for dyspepsia?

A

If it came with any of the ALARMS symptoms:

  • Anorexia
  • Loss of Weight
  • Anaemia
  • Recent Onset >55 yrs or Persistant despite Treatment
  • Melaena/Haematemesis or Mass
  • Swallowing problems (Dysphagia/Odynophagia)
18
Q

Define Haematemesis?

A

Vomiting blood

19
Q

Define Odynophagia?

A

PAin when swallowing

20
Q

NAme a few drugs that can cause dyspepsia

A

NSAIDs & Steroids
Ca Antagonists
Theophyllines
Nitrates

21
Q

What is the flow chart approach to dyspepsia?

A

Dyspepsia:

  • Alarms features?
  • > Yes = Upper GI endoscopy
  • No = Age?
  • > Over 55 = UGIE
  • Under 55 = Heliobacter Pylori test
  • > If +ve do eradication therapy and or symptom treatent with antacids (PPIs or H2R antagonists) and change lifestyle factors
22
Q

What are H2R antagonists?

A

Histamine H2 receptor antagonists

23
Q

What lifestyle factors affect dyspepsia?

A

Smoking
Drinking
Diet
Lack of exercise

Loss of weight is an indicator

24
Q

Define Gastritis

A

Inflammation in the gastric mucosa

25
How is gastritis diagnosed?
The clincal features can be seen on endoscopy then its confirmed histologically wiht a biopsy
26
What are the 3 typs of Gastritis?
A - Autoimmune (attacking parietal cells -> low HCl) B - Bacterial (Heliobacter Pylori) C - Chemical (Bile/NSAIDs)
27
What types of peptic ulcer are more common and with who?
Duodenal over gastric Men more than women Older more than younger
28
What can cause a peptic ulcer?
``` Heliobacter Pylori NSAIDs Smoking In rare cases: - Zollinger-Elison Syndrome - Hyperparathyroidism - Crohn's Disease ```
29
What are the symptoms of a peptic ulcer?
- Epigatric pain which may be relieved by antacids (point tenderness over diffuse) - Pain at night or when hungry (more often a DU) - Back Pain (may be a penetrating DU) - Nausea or vomiting - Weight loss/anorexia If it bleeds you might get haematemesis or melaena It often appears as just epigastric pain or tenderness
30
How is a peptic ulcer treated?
Antibiotics if its Heliobacter Pylori Antacids: - PPIs (omeprazole) - H2 receptor antagonist (ranitidine) Stop any NSAIDs Surgery - but only if complicated
31
Complications of a peptic ulcer?
Acute Bleeding: - Melaena - Haematemesis Chronic Bleeding: - Iron deficient anaemia Perforate Gastric outlet Obstruction: - Oedema - Fibrotic Stricture
32
What is gastric outlet obstruction?
Gastric outlet obstruction is not a single entity; it is the clinical and pathophysiological consequence of any disease process that produces a mechanical impediment to gastric emptying. Clinically it appears: - Vomiting, fermented foodstuffs not bile - Early Satiety - Abdominal Distension - Weight Loss - Gastric Splash - Dehydration - Loss of HCl in vomit -> Metabolic Alkalosis
33
What tests can we do for gastric outlet obstruction?
Bloods: - Low Cl, Na, K - Renal Impairment Upper GI endoscopy: - Prolonged Fast First or aspirate gastric contents - Then identify if its a stricture, ulcer or cancer
34
How do we treat gastric outlet obstruction?
Treat the underlying cause: - If its a stricture use Endoscopic Balloon Dilatation - Otherwise it often requires surgery
35
How common is gastric cancer and what histological types is it?
Second most common GI cancer 5 yr survival <20% Most are adenocarcinomas in the glandular epithelium. Can also be a lymphoma (MALT) or sarcoma (GIST)
36
MALT and GIST?
``` MALT = Mucosa Associated Lymphoid tissue GIST = GastroIntestinal Stromal Tumour ```
37
How do patients with gastric cancer present?
- Dyspepsia - Early Satiety - Nausea & Vomiting - Weight Loss - GI bleeding (haematemesis/Malaena) - Fe deficient anaemia - Gastric Outlet obstruction
38
Explain the aetiology of gastric cancer?
None of these are a direct cause but all are associated with gastric cancer: - Diet - Genes - Heliobacter Pylori - Smoking - Previous Gastric pathology or resection - Biliary Reflux - Family History
39
Explain the inheritance of gastric cancer?
- Most are actually sporadic with no demonstratable inherited component - <15% show familial clustering - 1-3% of cases are a heritable gastric cancer syndrome
40
How do we investigate a case of gastric cancer?
An upper GI endoscopy with biopsy to confirm using a histological diagnosis. Then stage with a chest and abdominla CT checking: - Lymph nodes - Lungs - Liver - Peritoneum - Marrow
41
How do we treat gastric cancer?
Surgery Chemotherapy DUH!