Upper GI disease Flashcards
understand the anatomy, structure and function of the GI tract, understand the pathophysiology and management of GORD and PUD
what anatomy is in the upper GI tract?
5
- mouth
- pharynx
- oesophagus
- stomach
- small intestine (duodenum)
what anatomy is in the lower GI tract?
4
- small intestine (jejunum and ileum)
- colon (ascending, transverse, descending, sigmoid)
- rectum
- anus
what is the function of the GI tract?
4
- ingestion of food - mouth, pharynx
- digestion of food - teeth, saliva, stomach acid, stomach enzymes, bile, pancreatic enzymes
- absorption of nutrients - small intestine, colon
- excretion of waste products - anal canal
what prevents the reflux of food and stomach contents in the oesophagus?
sphincters - upper and lower oesophageal sphincter
what are the layers of the GI tract?
- mucosa
- submucosa
- muscularis externa
- adventitia/serosa
what kind of tissue is the oesophagus made of? what is its purpose?
fibromuscular tissue
* transports food from pharynx to somach via peristalsis
what are the functions of the stomach?
3
- digestion - chemical (HCl, pepsin, lipase) and mechanical
- absorption - B12, alcohol, water
- endocrine - gastrin (HCl secretion), CCK (gall bladder)
what do chief cells and parietal cells produce?
- chief cells - pepsin (protein breakdown into polypeptides)
- parietal cells - HCl, intrinsic factor (needed for the absorption of B12)
what is gastro-oesophageal reflux disease (GORD)?
acid and stomach contents flow through the lower oesophageal sphincter and into the oesophagus
what are the causes of GORD?
3
- laxity of lower oesophageal sphincter - caffiene
- increasead gastric pressure - obesity, pregnancy
- delayed gastric emptying - eating too much
what does GORD cause?
gastric acid irritates the oesophageal mucosa
* causes metaplasia of oesophageal epithelium (Barrett’s oesophagus = precancerous)
what are the signs/symptoms of GORD?
6
- dyspepsia (indigestion/heartburn)
- epigastric pain
- bloating
- nausea/vomiting
- vocal hoarseness
- **dental erosion **
what are the risk factors for GORD?
8
- stress/anxiety
- smoking
- alcohol
- trigger foods (caffiene, chocolate, fatty meals)
- obesity
- NSAIDs
- pregnancy
- lying flat after large meal
how do you diagnose GORD? what are the red flag features?
6
GP referral for upper GI endoscopy
* unexplained weight loss
* loss of appetite
* dysphagia (difficult swallowing)
* vomiting blood
* rectal bleeding or blood in snot
* unexplained iron deficiency anaemia
how do you manage GORD?
5
- lifestyle changes - weight loss, stop smoking, reduce alcohol, smaller meals
- antacids - gaviscon, rennie
- proton pump inhibitors - omeprazole, lansoprazole
- H2 receptor antagonist - ranitidine
- surgery - tighten lower oesophageal sphincter
how do antacids, proton pump inhibitors and H2 receptor antagonists work?
- antacids - create a layer on surface of gastric acid, neutalising pH and relieving symptoms
- PPIs - inhibits the proton pump of parietal cells, reducing the production of HCl
- H2 receptor antagonists - bind to H2 receptors on parietal cells, preventing the binding of histamine and stimulation of parietal cells to produce HCl
what is Barrett’s oesophagus?
metaplasia of oesophageal epithelium at the gastro-oesophageal junction
* squamous to columnar epithelium
what are the dental inplications of GORD?
3
- erosion (intrinsic)
- burning mouth symptoms
- taste disturbance - dysgeusia
what kind of cancer is oesophageal cancer?
- lower 1/3 adenocarcinoma - cancer of glandular tissue (Barrett’s oesophagus)
- upper 2/3 squamous cell carcinoma - smoking and alcohol
how do you manage oesophageal cancer?
4
- chemo/radiotehrapy
- surgery
- palliative
what is peptic ulcer disease?
a lack of mucus leading to ulceration in the stomach, duodenum and oesophagus
what are the risk factors of peptic ulcer disease?
2
- disruption to mucus barrier - NSAIDs and Helicobacter Pylori
- increased stomach acid production - stress, caffiene, smoking, alcohol, spicy foods
what are the symptoms of peptic ucler disease?
3
- dyspepsia - indigestion/heartburn
- epigastric pain
- nausea and vomiting
what are the complications from PUD?
5
- bleeding
- anaemia
- perforation of stomach/duodenum
- stricture - narrowing of oesophagus, hard to swallow
- stomach cancer
what is Helicobacter Pylori?
bacteria that lives in the stomach whose toxins cause mucosal damage and ulceration
how do you test or H. Pylori?
2
- breath test (looking for urea)
- stool antigen
how do you treat H. Pylori? how long is the treatment?
eradication therapy / triple therapy
1. **proton pump inhibitor **
2. amoxixillin
3. clarithromycin or metronidazole
7 days
what is the mechanism of action for NSAIDs?
inhibit the formation of prostaglandins via COX enzyme pathway
prostaglandins involved in inflammation
what is the difference between the COX-1 and COX-2 pathway?
- COX-1: prostaglandins help with gastric mucosal integrity and platelet aggregation
- COX-2: prostaglandins drive pain and inflammation
want to inhibit COX-2 not COX-1
how is PUD diagnosed?
endoscopy
how do you manage PUD?
4
- lifestyle measures - stress, alcohol, smoking, caffiene
- stopping NSAIDs
- eradication of H. Pylori
- long term PPI
what are the dental implications of PUD?
2
- NSAIDs - avoid use
- shared risk factors with oral cancer- smoking alcohol
