Melaena Flashcards
What is melaena?
Black tarry stools from upper GI bleed
Tarry colour and very offensive smell
Due to the alteration and degradation of blood by intestinal enzymes
Most common causes
Peptic ulcer disease
Liver disease
Gastric cancer
When should peptic ulcer + melaena be suspected?
Known active peptic ulcer disease
History of NSAIDs or steroid use
Dyspepsia like symptoms
H.pylori +ve
Can oesophageal varices cause melaena?
Yes, any significant melaena with known history of alcohol abuse should be urgently investigated for varices
Upper GI malignancy and melaena
Ulcerating oesophageal or gastric malignancies can present with melaena instead of haematemesis.
Other less common causes of melaena
Gastritis
Oesophagitis
Mallory-Weiss tear
Meckel’s diverticulum
Vascular malformations like Dieulafoy lesions
Key factors to ascertain from melaena hx.
Colour and texture of stool
Associated symptoms like haematemesis, abdo pain, hx of dyspepsia, dysphagia or odynophagia
PMH of smoking, alcohol and IBD
DH like steroids, NSAIDs, antigcoag and iron tablets.
What examination should be done?
DRE to confirm melaena + full abdo exam to see if there is epigastric tenderness, peritonism, hepatomegaly or any other stigmata of liver disease
Lab tests
Routine bloods like FBC, U&Es, LFTs and clotting
ABG for pH, base excess, lactate and signs of tissue hypoperfusion
Lab test findings
Acute bleed may or may not show anaemia
LFTs can show underlying liver damage
Drop in Hb and rise in urea:crea is indicative of upper GI bleed
Group and Save should be done as well
Definitive investigation in most cases
OGD which also forms part of the management
Colonoscopy or capsular endoscopy might be needed if OGD proves inconclusive.
Why is drop in Hb and rise in urea:crea ratio indicative of upper gi bleed?
Digested Hb produces urea as a byproduct
When might CT abdo with IV contrast be done?
To assess any active bleed especially if endoscopy is unremarkable or patient is too unwell for OGD.
RBC scintigraphy might be done as well
Initial management
ABCDE approach with resus + OGD
Peptic ulcer disease management
Injections of adrenaline + cauterisation of the bleed
40mg omeprazole IV also to control the acidic environment
Any H.pylori should be eradicated
