Ischaemic Bowel (Colitis)

Question 1

Define ischaemic colitis

Answer 1

1) most common form of ischaemic injury of GIT

2) occlusive or non-occlusive forms => compromised blood supply that can’t meet the metabolic needs of a region of colon

Question 2

Describe the epidemiology of ischaemic colitis

Answer 2

Usually in the elderly (80% cases in pts >60yrs)

Question 3

What are the risk factors for ischaemic colitis and how can they be classified?

Answer 3

Occlusive Vascular Ds vs Non-occlusive Vascular Ds
Occlusive - mesenteric a emboli; thrombosis; trauma
Non-occlusive - hypo-perfusion state; mechanical fx; medications; iatrogenic; increased coagulability

Watershed Areas
Marginal a of Drummond/Griffith’s pt
Sudeck’s pt

Question 4

Name the three progressive phases of ischaemic colitis

Answer 4

1) hyperactive phase
2) paralytic phase
3) shock phase

Question 5

Descibe the first phase of ischaemic colitis

Answer 5

Hyperactive Phase
Primary sx: severe (localised) abd pain; bloody stools
Many pts get better & don’t progress beyond this pt

Question 6

Describe the second phase of ischaemic colitis

Answer 6

Paralytic Phase
Abd pain => widespread
No bloody stools
abd = tender to touch
bowel motility decreases => abd bloating
absent bowel sounds

Question 7

Describe the third phase of ischaemic colitis

Answer 7

Shock Phase
fluids leak thru damaged colon lining
=> shock, metabolic acidosis w/ dehydration, hypotension, tachycardia, confusion
NB pts critical ill & need intensive care!

Question 8

What are the fx included in the classical triad of acute mesenteric ischaemia?

Answer 8

1) acute sev abd pain
2) no physical signs
3) rapid hypovolemia => shock

Question 9

How does a pt w/ ischaemic bowel present?

Answer 9

1) sudden onset crampy abd pain -> mild rectal bleeding (<24hrs)
2) diarrhoea + urge to defecate
3) abd exam: tenderness over affected colon, PR: heme-+ve stool
4) No fever, but raised WCC
5) if sev, marked tenderness w/ peritoneal signs + metabolic acidosis + septic shock

Question 10

What investigations do you do for a pt w/ ischaemic bowel?

Answer 10

FBC; ABG; U&E/Cr; PT/PTT; Amylase; LDH; NB markers for ischaemia (LFTs needed too)
AXR
CT-Abd
Stool Culture
Colonoscopy

Question 11

How do you manage a pt w/ ischaemic bowel?

Answer 11

Conservative vs Surgical
Conservative - NBM, fluids, NG tube suction, decompression via rectal tube, broad spectrum antibiotics, KIV parenteral nutr
Surgical - emergency laparotomy