Melena

Question 1

What is melena?

Answer 1

• 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

Question 2

Causes of upper GI bleed

Answer 2

• Peptic ulcer disease
• Variceal bleeding
• Malignancy

Question 3

RF for peptic ulcer disease causing bleeding

Answer 3

• Recent NSAID use
• Steroid use
• H-pylori infection

Question 4

How does PUD cause melena?

Answer 4

• Ulcer erodes through posterior gastric wall
• Erodes gastroduodenal artery
• = bleed

Question 5

Variceal bleeding - how?

Answer 5

• Portal HTN secondary to liver cirrhosis
• = dilation of porto-systemic anastomosis within oesophagus

Question 6

Most common cause of oesophageal varices bleeding

Answer 6

• Alcoholic related liver disease

Question 7

Other less common causes of melena

Answer 7

• Gastritis
• Oesophagitis
• Meckels diverticulum
• Small bowel tumout
• Vascular malformations - angiodysplasia

Question 8

History to ask for melena

Answer 8

• 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

Question 9

Examination for melena

Answer 9

• DRE needed
• Full abdominal exam - assess for peritonism, hepatomegaly, stigmata of chronic liver disease

Question 10

Why to ask about iron tablets?

Answer 10

• They can cause black stool
• Clarify timing started and timing melena started

Question 11

Bedside and bloods for melena presentation

Answer 11

• FBC
• U&E
• LFT
• Group and save
• Crossmatch if drop in Hb/haemodynamically unstable

Question 12

Characteristic blood results for upper GI bleed

Answer 12

• Drop in Hb
• Rise in urea:creatinine ratio

Question 13

Imaging for melena

Answer 13

• Gastroscopy - OGD - identify cause and allow for intervention

Question 14

How is urgency of OGD for melena determined?

Answer 14

• Glasglow blatchford bleeding score
• Risk stratify patients based purely on clinical and biochemical parameters

Question 15

Further investigations if OGD inconclusive

Answer 15

• 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)

Question 16

Management melena - ALL causes

Answer 16

• A-E assessment and manage accordingly
• Blood products - if low Hb or haemodynamically unstable (urgent)
• Correct deranged coagulation - FFP, platelets esp if impaired liver
• Underlying cause

Question 17

Management of PUD causing melena

Answer 17

• Injection of adreanline and cauterisation of bleeding during endoscopy
• Then high dose PPI

Question 18

Management of varices causing melena

Answer 18

• Urgent endoscopy - then endoscopic banding
• Resuscitation using blood products
• Prophylactic abx
• Somatostatin analogues - eg terlipressin, ocreotide to reduce splanchnic blood flow

Question 19

What is endoscopic banding doesn’t work for variceal bleeding?

Answer 19

• Sengstaken Blakemore tube can be used if severe or uncontrolled
• = temporarily compress bleeding

Question 20

Management of upper GI malignancy cause of melena

Answer 20

• Biopsies
• Definitive surgical and oncological plan needed