GI bleeding Flashcards
Top differentials for hematemesis in patient with pneumonia on Abx
ulcer and gastritis
How do you differentiate between melena and iron supplements
melena smells
Occult GI bleeding positive = think …
colon cancer
Top differential in alcoholic with haematemesis
varices secondary to liver disease
Differences in the presentation of oesophageal vs gastric tumour
oesophageal tumour more likely to cause haematemesis at a later stage after dysphagia, whereas gastric tumour will have necrosis in ulcer so first presentation is often haematemesis
Mechanism of stress ulcers
Vagal stimulation due to acid hyper secretion, systemic acidosis causes mucosal injury, splanchnic vasoconstriction - hypoxia due to reduction of blood flow
Mallory weiss tears are common in
alcoholics (often also have oesophagitis) and bulimics
2 causes of peptic ulcer disease
Increased acid: zollinger Ellison syndrome, hyperparathyroidism, chronic renal failure
Reduced mucosal defence: H pylori (most common), NSAIDs, cigarettes, corticosteroids
How does H pylori weaken mucosal defence
Mucous is rich is carbs, H pylori digests carbs and exposes mucosa to action of acid
Functions of paracetamol
1 = redue temperature
2= painkiller
How does codeine cause constipation
Inhibits peristalsis of bowels, contents become more dehydrated, vicious cycle
Pain killers for colic
Buscopan > paracetamol/NSAIDs
Mechanism behind gastroesophageal varices
Resistance to portal blood flow, angiogenic factors and increased nitrous oxide production in splanchnic vascular bed, splanchnic arteriolar vasodilation and increased portal outflow
Varices temporary fix
balloon can be used to compress
Uncommon causes of haematemesis
Dieulafoy’s lesion- dilated aberrant submucosal vessel that erodes overlying epithelium not associated with ulcer (endoscopy reveals active arterial pumping from a site)
◦ Watermelon stomach or gastric antral vascular ectasia
◦ Aorta-enteric fistula (often infected prosthetic aortic graft eroding into intestine), some present with back/abdo pain, others with fever associated with sepsis
Benign lesions of oesophagus or stomach
Lipomas, polyps, blue rubber bleb Nevus syndrome
What type of cancer is most common in oesophagus
adenocarcinoma more than Squamous cell carcinoma (look at barrets oesophagus)
Points to remember when diagnosing GI bleed
where is blood loss, colour/smell/consistency, amount, history of PUD, signs of chronic liver disease, recent negation of NSAIDs/aspirin/warfarin, history of retching
Diverticulitis vs cancer
Cancer more common cause of bleeding in over 50, diverticulitis could present with abdominal pain too
Fissure and piles gender distribution
Piles more common in men, fissures more common in women
What is always indicated with PR bleeding
DRE/PR
Rectal cancer order of symptoms usually
pain and then bleeding
Angiodysplasia leads to bleeding in presence of
constipation or blood thinners
When to think about inflammatory/ischaemic colitis or UC
Abdo pain, raised inflammatory markers, haematochezia
