Dyspepsia and peptic ulcer Flashcards
what is dyspepsia
bad digestion
describe the rough organisation of a gastric pit cell from top to bottom
goblet cells parietal cells chief cells D cells G cells
what do the cells of the gastric pit secrete
goblet - mucus - protect stomach lining
parietal cells - gastric acid - HCL
chief cells - pepsinogen - protease precursor
D cells - somatostatin - inhibits acid secretion
G cells - gastrin - stimulates acid secretion
how is HCL secreted from parietal cells
on basal side near interstitial fluid and capillary there is a Cl- HCO3 anti-transporter (Cl in and bicarbonate out)
the cl then moves passively down its con gradient out of the apical surface into the lumen
h20 in the cell splits and binds with co2 to get bicarbonate which leaves the basal side but the H+ from water uses active transport to pump H+ into the lumen and K+ back into the cell
K then freely leaks back into the lumen to repeat
describe the pathway of stimulation of parietal cells to release HCL
G cells release gastrin which stimulate ECL cells to release histamine. histamine stimulates parietal cells to release HCL
enteric neurons also release ACh which stimulates parietal cells
describe the negative feedback of HCL release from parietal cells
HCL stimulates somatostation releasing cells to release somatostatin
they directly inhibit parietal cells
inhibit ECL cells and inhibit G cells
what do PPI’s do
proton pump inhibitors stop HCL release from parietal cells
what do H2 blockers do
stop ECL cells from releasing histamine
what are the signs and symptoms of a peptic ulcer
epigastric pain - after eating, may be relieved by antacids, eating or drinking milk epigastric tenderness nausea anorexia weight loss
what are the four definitions of dyspepsia
D with alarm symptoms - red flag features
uncomplicated D - without red flag features
uninvestiagated D - D presenting to a clinician for the first time
functional D (non-ulcer) - D but no structural cause for symptoms at upper GI endoscopy
what are alarming features of dyspepsia
weight loss dysphagia persistent vomiting haematemesis or melaena (dark sticky faeces - internal bleeding) palpable gastric mass family history or gastric cancer D onset over 45-55 years
what are the potential causes of dyspepsia
gastro-oesophageal reflux disease - 13%
peptic ulcer - 8%
gastric cancer less than 1%
functional dyspepsia - 80% due to normal endoscopy
which countries most commonly have dyspepsia
russia, UK, south american countries
how much does dyspepsia cost the Uk per year
£500 mil
how common is dyspepsia
prevalence of 20-40%
incidence of around 2% per year
what is the prognosis variability of dyspepsia
40% long term symptoms
60% experience resolution of symptoms
when would you do an endoscopy for dyspepsia
if there are any signs of alarm symptoms
what are the approaches to uncomplicated/simple dyspepsia
endoscopy, test for H pylori, empirical PPi
how do you know which treatment to use for uncomplicated dyspepsia
endoscopy is best for effect of symptoms but not cost effective
what are the common causes of peptic ulcer
H pylori 5% of cases non-steroidal and aspirin
what are the more rare causes of peptic ulcer
zollinger-ellison syndrome
crohns disease
what is the relationship between helicobactor and peptic ulcer
casually implicated in the disease
60% gastric and 80% duodenal ulcer as well strong association with gastric cancer
how was helicobactor eradicated
PPI’s and 2 antibiotics
how does H pylori fester in the stomach
bacterium produces urease which turns urea into ammonia and water which neutralises stomach acid for survival
what are the non invasive and invasive measures for diagnosing H pylori
non: carbon urea breath test H pylori serology Hy pylori stool antigen invasive rapid urease test biopsy
what do you treat H pylori with
PPI with two antibiotics such as amoxicillin, calithromycin or metronidazole
what are three complications of peptic ulcer
perforation
bleeding
gastric outlet obstruction - pylori stenosis
how do you treat peroration or pyloric stenosis
surgery
how do you treat bleeding from peptic ulcer
endoscopy
what are the symptoms and signs of peptic ulcer bleeding
haematemesis coffee ground vomiting melaena rectal bleeding tacky cardia hypotension
some strains of H pylori express which toxins and what do they do
Cage and VacA which produce higher levels of inflammation
which blood group is more susceptible to peptic ulceration
blood group O has increased risk of duodenal ulceration
what is the biochemical name for the proton pump
H+/K+ ATPase
how does aspirin cause excess gastric acid release
COX makes prostoglandins from arachidonic acid. PGE2 modulates gastric secretion via Gi which inhibits adenylate cyclase. inhibition of COX via aspirin reduces prostolglandins which in turn leads to a rise in acid secretion
which COX is responsible for inflammation
COX2
which COX is responsible for effects on gastric mucosa
COX1
why is celecoxib preferred in long use over ibuprofen
celexoib is more specific to COX 2 and therefore less likely to produce ulceration
why does aspirin cause haemorrhages from peptic ulcer
inhibits cox and inhibits thromboxane A2 and stops platelet aggregation - antiplatelet
what does H2 antagonists do for anti-ulcer drugs
ranitidine (zantac)
famotidine (pepcid)
binds to H2 receptor preventing binding of histamine and decreasing acid release
how do PPI’s aid as anti-ulcer drugs
lansoprazole
omeprazole
pantoprazole
direct inhibition of K+/H+ ATPase which pumps H+ ions into the stomach
what is melaena and what is it a sign of and what is it associated with
dark stool - blood in stool - could be due to peptic ulcer
can cause anaemia and therefore shortness of breath
what physiological observations would you make for someone with suspected haemorrhage peptic ulcer
pulse - tachycardia
blood pressure - hypotension
indicative of blood loss
what abnormalities would you see on a blood test with peptic ulcer bleeding
below normal levels of blood (normal 13-17 g Hb/dl in men, 11-15 in women)
test for urea - would be raised
what additional test would you do if someone had haemorrhage peptic ulcer
biopsy and urease test for H pylori
