H.Pylori & Gastric Secretion Flashcards
Symptoms of Dyspepsia
Upper Abdominal/Retrosternal pain/discomfort. Bloating Reduction in appetite Heartburn Burping, Reflux Nausea/ Vomitting
Lasting >4 weeks
General Causes of Dyspepsia
Drugs Psychological Coeliac Disease Pancreatic Disease Hepatic (gallstones) Upper GI Lower GI (IBS/Cancer although non-typical presentation)
Upper GI causes of dyspepsia
GORD
Peptic Ulcer
Gastric Cancer
What is GORD
Gastro-oesophageal reflux disease. Caused by weakening of the lower esophageal sphincter causing gastric acid to leak into the oesophagus.
Describe the investigation for dyspepsia
Bloods - FBC, ferritin, lfts, calcium, glucose, coeliac serology/ serum igA
Drug History
Lifestyle - alcohol, diet, smoking, exercise, weight reduction
Drug History - Classes of Drugs to check for:
NSAIDS - naproxen, dicolfenac, ibuprofen
Steroids - corticosteroids
Biphosphonates - osteoporosis drugs.
Ca+ antagnoist - CCBs, amplodopine
Nitrates - GTN
Theophyllines
When to refer for endoscopy?
ALARMS
A - Anorexia L - Loss of Weight A - Anaemia (irondeficiency) R - Recent onset >55 years, persistent despite treatment. M - Melaena/Haematemesis or Mass S - Swallowing - Dysphagia
First Step Treatment of Dyspepsia in the absence of ALARMS
Antacid Medications - Gavisgon
H2 receptor antagonists - ranitidine
Then:
H.Pylori Test - HPSA test, stopping antibiotics 4 weeks prior, H2RA one day prior. Start Omeprazole.
Steps if H.Pylori test negative
If PPI (omeprazole) has resolved after a month, step down therapy.
> 55 refer urgently to Upper GI cancer endoscopy referral.
<55 step up treatment, if still no response refer routinely to GI
Steps if H.Pylori test positive
Eradicate H.Pylori with combination of antibiotics/PPI
If symptoms are ongoing, a urea breath test, if positive use second line eradication therapy for H/pylori.
If negative trial PPI treatment,
if still negative refer urgently for cancer upper GI endoscopy.
What is Helicobacter pylori?
Gram Negative, microaerobic, spiral shaped (s-shaped) mobile via flagella.
Infects 50% of the world population and is acquired in childhood.
The bacteria colonises in the gastric mucosa and does not penetrate the epithelia layer and evokes immune response in the underlying mucosa
Outcome of H.Pylori Infection.
Dependant on site, characteristics of bacteria and host factors.
Asymptomatic Chronic Gastritis Gastric/Duodenal Ulcer Intestinal Metaplasia Gastric Cancer/MALT Lymphoma
Process of Serology
What Ig is tested in H.Pylori?
Examination of blood serum to examine proteins made by the immune system (immunoglobulins)
H.Pylori Non-invasive Testing
Serology
Urea Breath Test
ELISA - stool antigen test. (off PPI for two weeks)
H.Pylori invasive testing
Histology - gastric biopsies
Culture - gastric biopsise
Rapid slide urease test (CLO)
Define ELISA
Enzyme-linked immunosorbent assay. Used to detect antibodies made in response to specific infection
Why do we use a urea breath test
H.pylori secretes urease which catalyses urea to ammonia.
The patient swallows a tablet containing urea made from isotopic carbon . If H.pylori is present, the urea is broken down into ammonia and CO2.
The CO2 is absorbed and exhaled via the lungs where the isotopic carbon is exhaled.
Isotopic carbon is low in nature, if there is no infection, the test results are negative for infection (isotope negative)
Causes of Gastritis
Autoimmune - Parietal Cells
Bacterial - H.pylori
Chemical- bile/nsaids.
Causes of Peptic Ulcers
H.Pylori
NSAIDS
Smoking
Rarely caused bu Hyperparathyroidism, Crohn’s Disease, Zollinger-Ellison Syndrome
Define Hyperparathyroidism
Overproduction of parathyroid hormone causing hypercalcaemia.
Zollinger-Ellison Syndrome
Disease where tumors form from the pancreas or the upper duodenum (gastrinomas) which secetre large amounts of gastrin. Causing the stomach to overproduce acid.
Symptoms associated with peptic ulcers
Epigastric Pain Nocturnal/ Hunger (more common in DU) Back pain (posterior DU) Nausea and Vomiting Weight loss and anorexia
Ulcer Bleed may cause haematemesis, melaena or anaemia
Treatment of Peptic Ulcers
Eradication Therapy.
Antacid - PPI (omerpraole) or H2RA (ranitidine)
Stopping of NSAIDS if possible and provided with other protective agents.
Complications are treated as they arise
Antibiotic Treatment of H.Pylori
Triple therapy for 7 days.
- Clarithromycin
- Amoxicillin (or tetracycline)
- PPI (omeprazole)
May fail due to ABX resistance or poor compliance. Second line treatment dependant of resistance profiles.
Complications of Peptic Ulcers
Acute Bleeding - melaena and haematemesis
Chronic Bleeding - iron deficiency anaemia
Performation
Fibrotic Stricture
Gastric Outlet Obstruction (oedema or stricture)
Symptoms of Gastric Outlet Obstruction
Vomiting Weight Loss Abdominal Distension Gastric Splash Early satiety Metabolic alkalosis Weight loss Dehydration (loss of H+ and Cl- in vomit)
Bloods - low Cl, low Na, low K renal impairment.
Diagnosed with UGIE - upper GI endoscopy to identify cause.
What is a gastric outlet obstruction?
Also known as pyloric obstruction - mechanical obstruction.
What causes a gastric outlet obstruction
Stricture, Ulcer and Cancer
Define metabolic alkalosis
A metabolic condition in which pH is raised beyond 7.35-7.45. Increase in serum bicarbonate, caused by loss of H+ from the body or gain in HCO3
Treatment of Gastric outlet obstruction
Endoscopic balloon dilatation or surgery.
Types of Gastric Cancers
Majority - Adenocarcinoma
MALT - mucosa associated lymphoid tissue (lymphoma)
GIST GI stromal tumour (soft tissue sarcoma)
Presenting Symptoms of Gastric Cancer
Dyspepsia Early satiety Nausea and vomiting weight loss GI bleeding Iron deficiency anaemia gastric outlet obstruction
Causes of gastric cancer
Diet, genetics, smoking, h.pylori, gastric ulcers, family history
Gastric Cancer Genes
Accounts for 1-3%
HDGC, AD, CDH-1 gene
Management of gastric cancer
Endoscopy and Biopsy - to make a histological diagnosis.
Staging - CT chest/abdo - lymph nodes and liver/lungs/peritoneum/bone marrow.
MDT discussion
