Melena Flashcards
1
Q
What is melena?
A
- Black, tarry stools often due to upper GI bleeding
- Characteristic tarry colour and offensive smell, difficult to flush away
- Stool consistency changes due to alteration and degredation of blood via intestinal enzymes
2
Q
Causes of upper GI bleed
A
- Peptic ulcer disease
- Variceal bleeding
- Malignancy
3
Q
RF for peptic ulcer disease causing bleeding
A
- Recent NSAID use
- Steroid use
- H-pylori infection
4
Q
How does PUD cause melena?
A
- Ulcer erodes through posterior gastric wall
- Erodes gastroduodenal artery
- = bleed
5
Q
Variceal bleeding - how?
A
- Portal HTN secondary to liver cirrhosis
- = dilation of porto-systemic anastomosis within oesophagus
6
Q
Most common cause of oesophageal varices bleeding
A
- Alcoholic related liver disease
7
Q
Other less common causes of melena
A
- Gastritis
- Oesophagitis
- Meckels diverticulum
- Small bowel tumout
- Vascular malformations - angiodysplasia
8
Q
History to ask for melena
A
- Colour and texture of stool - jet black, tar like, sticky
- Associated symptoms - haematemesis, abdominal pain, weight loss, dysphagia, dyspepsia
- PMH - smoking and alcohol
- DH - steroids, NSAIDs, anticoags, iron tablets
9
Q
Examination for melena
A
- DRE needed
- Full abdominal exam - assess for peritonism, hepatomegaly, stigmata of chronic liver disease
10
Q
Why to ask about iron tablets?
A
- They can cause black stool
- Clarify timing started and timing melena started
11
Q
Bedside and bloods for melena presentation
A
- FBC
- U&E
- LFT
- Group and save
- Crossmatch if drop in Hb/haemodynamically unstable
12
Q
Characteristic blood results for upper GI bleed
A
- Drop in Hb
- Rise in urea:creatinine ratio
13
Q
Imaging for melena
A
- Gastroscopy - OGD - identify cause and allow for intervention
14
Q
How is urgency of OGD for melena determined?
A
- Glasglow blatchford bleeding score
- Risk stratify patients based purely on clinical and biochemical parameters
15
Q
Further investigations if OGD inconclusive
A
- CT angiogram - assess for active bleeding, esp if ongoing +/- haemodynamic compromise
- Colonoscopy - esp if haemodynamically unstable ensure cause is not proximal eg caecum tumour
- IF STILL normal - capsule endoscopy or RBC scintigraphy (tag RBC with radioactive material)