Bowel Ischaemia - Ischaemic Colitis and Mesenteric Ischaemia

Question 1

Bowel Ischaemia

Answer 1

Small intestines
Acute mesenteric ischaemia
Chronic mesenteric ischaemia (intestinal angina)

Colon
Ischaemia colitis

Question 2

Causes of acute mesenteric ischaemia

Answer 2

Arterial - embolism (high link w/ AF)
thrombosis or external compression
venule thrombosis
and hypoperfusion - HF, sepsis

Question 3

Presentation of acute mesenteric ischaemia

Answer 3

Classic triad:
Acute ischaemia: severe, out of proportion to abdominal signs
CONTSANT AND CENTRAL

Chronic ischaemia: colicky, intermittent, post-prandial and described as ‘intestinal angina’

No abdo signs on examination
Rapid hypovolaemia > shock (hypotensive/tachycardic)
Nausea and vomiting

Absence of bowel sounds as motility decreases: late sign

> > > > AF + severe abdo pain = AMI«<

Question 4

Acute mesenteric ischaemia investigations

Answer 4

ECG - AF is MC cause

Diagnostic: Abdo CT angiography
- visualise blockages (difficult to perform)

Bloods:
increased Hb concentration due to blood loss
metabolic acidosis + raised lactate
-

Question 5

Management of acute mesentric isschaemia

Answer 5

Fluid resuscitation
IV heparin
IV broad spec- Antibiotics (metronidazole)

Surgery to remove necrotic bowel/revascularize
bowel resection
endovascular revacularisation

Mortality: >50%

Question 6

Causes of ischaemic colitis

Answer 6

Thrombosis
Emboli
Low flow states (low CO/arrhythmias)
Surgery

Question 7

Presentation of ischaemic colitis

Answer 7

Sudden onset LIQ pain
Passage of bright red bloody stools
+/- Signs of hypovolaemic shock (tachycardia, fatigue)

Question 8

Ischaemic colitis investigations

Answer 8

1st line: CT to rule out rupture

Gold standard: colonoscopy + biopsy

Question 9

What are the arteries supplying the bowels

Answer 9

The coeliac trunk supplies the proximal part of the duodenum, whereas the superior mesenteric artery (SMA) supplies the rest of the small bowel and up to two thirds the way along the transverse colon. The remaining part of the colon is supplied by the inferior mesenteric artery (IMA). Mesenteric ischaemia refers to pathology affecting the SMA.

Question 10

complications

Answer 10

Bowel infarction and perforation