malaena

Question 1

define

Answer 1

• Melaena is the passage of black, tarry stools.
• The stools have a characteristic and offensive smell due to the presence of blood that has been digested by intestinal enzymes and bacteria.
• The degradation of the blood also accounts for the dark colouration.

usually due to an upper gi bleed

Question 2

ddx

Answer 2

commonest causes of upper gi bleed:

• PUD
• variceal bleeds [from liver disease]
• upper gi malignancy

other causes less common:

• • gastritis
• oesophagitis
• mallory weiss tear
• meckel’s diverticulum
• vascular malformations [eg. dieulafoy lesion]

Question 3

when would you suspect PUD in a patient with malaena

Answer 3

• Known active peptic ulcer disease.
• H. Pylori positive.
• History of NSAID or steroid use.
• Previous epigastric symptoms suggestive of ulceration.

bleeding will occur if an ulcer erodes through the posterior gastric wall into the gastroduodenal artery.

tbh extensive bleeding can occur with the erosion of any blood vessel.

Question 4

define oesophageal varices

Answer 4

=dilations of the porto-systemic anastomoses in the oesophagus.

• They most commonly occur due to portal hypertension secondary to liver cirrhosis and
• are very prone to rupture
• take alcohol hx from pt, is there a hx of alcohol abuse?? if yes, suspect and rx asap.

Question 5

features of upper gi malignancy

Answer 5

about other upper GI symptoms, weight loss, or relevant family history, potentially suggestive a diagnosis of malignancy.

Question 6

s/s you need to ascertain from hx

Answer 6

• Colour and texture of the stool – jet black, tar-like, and sticky.
• Associated symptoms – including haematemesis, abdominal pain, or a history of dyspepsia, dysphasia or odynophagia.
• Past medical history – including smoking and alcohol status, and inflammatory bowel disease.
• Drug history – use of steroids, NSAIDs, anticoagulants, or iron tablets.
• A PR exam is essential to confirm the melaena, as well as a full abdominal exam assessing for epigastric tenderness or peritonism, hepatomegaly, and for any stigmata of liver disease.

Question 7

ix

Answer 7

1. Routine bloods (FBC, U&Es, LFTs, and clotting):

• may not initially show an anaemia in fbc
• liver damage as a potential cause.
• Any drop in haemoglobin and rise in the urea:creatinine ratio* is very indicative of an upper GI bleed.
• a Group and Save requested;
• those with significant melaena (especially suspected variceal bleed) should have at least 4 units of blood cross-matched.

2.Arterial blood gas:

• Useful in bleeding or septic patients, especially for the pH, pO2, and lactate, for signs of tissue hypoperfusion.

3.Oesophagogastroduodenoscopy (OGD):

The definitive investigation in most cases of melaena

_4.CT abdomen with IV contrast (_triple phase)

can be useful in assessing any active bleeding, especially if endoscopy is unremarkable or the patient is too unwell to undergo invasive investigation.

_5.RBC Scintigraph_y is a more sensitive test that can be used to identify active bleeding, however is currently only used routinely in select centres

Question 8

mx

Answer 8

1. critically ill pts - abcde approach
2. once pt stable/if inital resus attempts are ineffective - do endoscopy

• during ogd a range of therapeutic options can be done:
  
  • Peptic ulcer disease –
    • requires injections of adrenaline and cauterisation of the bleeding.
    • High dose intravenous PPI therapy should be administered (e.g. IV 40mg omeprazole) to control the acidic environment.
  • Oesophageal varices – management should be swift and performed at the same time as active resuscitation, including the use of blood products.
    
    • Endoscopic banding is the most definitive method of management but can be technically difficult.
    • Prophylactic antibiotic therapy should be initiated, alongside somatostatin analogues (e.g. terlipressin or octreotide), acting to reduce splanchnic blood flow and hence reduce bleeding.
  • A Sengstaken-Blakemore tube can be used in severe or uncontrollable cases, inserted to the level of the varices and inflated to compress the bleeding to act as a temporary control
• Upper GI malignancies – will require biopsies to be taken and a definitive long-term surgical and oncological management to be put in place
  3. blood transfusions- give to those with low hb r ongoing significant blood loss
  4. correct any derranged coag as appropriate eg. FFP or reversible agents if pt is on anti-coag rx.