Bowel Ischaemia - Ischaemic Colitis

Question 1

Definition

Answer 1

Affects the large bowel - ischaemia of colonic arterial supply = colon inflamed due to hypoperfusion

Question 2

Epidemiology

Answer 2

Older age

Question 3

Risk factors

Answer 3

Older age = underlying atherosclerosis + vessels occlusion
Younger population = women taking contraceptive pill, thrombophilia, + vasculitis

Question 4

Aetiology

Answer 4

THROMBOSIS (+/- ATHEROSCLEROSIS) = MC
EMBOLI
DECREASED CO + ARRHYTHMIAS (e.g. Hx of AF)
Drugs:
- oestrogen
- antihypertensives
- vasopressin
- contraceptive pill

Question 5

Most common areas affected

Answer 5

Watershed areas:
- SPLENIC FLEXTURE (MC)
- Sigmoid colon + cecum

Question 6

Pathophysiology

Answer 6

Occlusion of branched of the superior mesenteric artery (SMA) or inferior mesenteric artery (IMA), often in the older age groups
The anatomy of the vascular supply to the colon results in a watershed area = most common site affected

Question 7

Signs + symptoms

Answer 7

LLQ pain + BRIGHT BLOOD STOOL
+/- signs of hypovolaemic shock

Question 8

Diagnosis

Answer 8

FIRST LINE = Urgent CT to rule out perforation
GOLD STANDARD = COLONOSCOPY + BIOPSY
- Only Done AFTER Px has fully recovered to exclude the formation of a stricture at the site + confirm mucosal healing
Rule out other cause - stool sample = H. Pylori

Question 9

Treatment

Answer 9

Symptomatic = IV fluids + Abx (prophylactic)
Gangrenous (infarcted colon) = ONLY SURGERY

Question 10

Complications

Answer 10

Perforation = Spontaneous bacterial peritonitis
Strictures = obstruction