Bowel ischaemia

Question 1

What are the 3 main types of bowel ischaemia?

Answer 1

• Acute mesenteric ischaemia
• Chronic mesenteric ischaemia
• Ischaemic colitis/Chronic colonic ischaemia

Question 2

What is acute mesenteric ischaemia?

Answer 2

ACute interruption in the blood supply to the mesentery. It can result from occlusion of arterial inflow, occlusion of venous outflow or failure of perfusion

Question 3

What are causes of acute mesenteric ischaemia?

Answer 3

• SMA thrombosis/embolism
• AF
• Mesenteric vein Thrombosis
• Low flow states - heart failure
• Trauma
• VAsculitis
• Radiotherapy
• Strangulation

Question 4

How do those with acute mesenteric ischaemia tend to present?

Answer 4

Triad of

• Acute severe abdominal pain - constant, periumbilical or concentrated to RIF
• Features of hypovolaemic shock
• Distended, tender abdomen, with absent bowel sounds

Can also have in later stages

• Haematochezia/malaena
• Diarrhoea

Degree of illness is far out of proportion with signs

Question 5

If you suspected acute mesenteric ischaemia, what investigations would you consider doing?

Answer 5

• Bloods - FBC, U+E’s, ABG
• ECR
• Erect CXR
• AXR
• CT/MR angiography/Formal arteriography

Question 6

What might you see on FBC in someone with acute mesenteric ischaemia?

Answer 6

• Increased Hb - due to increased plasma loss
• Increased WCC

Question 7

What might you see on U+E’s in someone with acute mesenteric ischaemia?

Answer 7

• Uraemia
• Elevated creatinine

Question 8

What might you see on ABG in someone with acute mesenteric ischaemia?

Answer 8

• Acidosis
• Elevated lactate

Question 9

What might you find on ECG in someone with acute mesenteric ischaemia?

Answer 9

Indication of cause

• AF
• Arrhythmia
• ACute MI

Question 10

What might you find on AXR in someone with suspected acute mesenteric ischaemia?

Answer 10

May inidicate aetiology

• Air fluid levels
• Bowel dilation
• Bowel wall thickening
• Pneumatosis

Question 11

How would you manage someone with acute mesenteric ischaemia?

Answer 11

ABCDE

• Supportive - NG tube, Fluid resiscitation, Antibiotics
• LMWH - cases of venous thrombosis
• Consider Local thrombolytics
• Surgical
  
  • Revascularisation
  • Resection

Question 12

What are life-threatening complications of acute mesenteric ischaemia?

Answer 12

• Septic peritonitis
• SIRS
• Multi-organ failure

Question 13

What are features of chronic mesenteric ischaemia?

Answer 13

Triad of:

1. Severe colicky, post-prandial abdominal pain - ‘gut cluadication’
2. Weight loss - eating hurts
3. Upper abdominal bruit

May also have

• Bloating
• PR bleeding
• Malabsorption
• Nausea + Vomiting

Question 14

What tests would you do if you suspected chronic mesenteric ischaemia?

Answer 14

CT angiography/Contrast enhanced MR angiography

Question 15

How would you manage someone with chronic mesenteric ischaemia?

Answer 15

• Percutaneous transluminal angioplasty + stent insertion
• Consider open revascularisation - not really used anymore

Question 16

What is chronic mesenteric ischaemia also known as?

Answer 16

Intestinal angina

Question 17

What are symptoms of ischaemic colitis?

Answer 17

Hyperactive phase - > 80% do not progress past this

• Sudden onset of crampy abdominal pain (usually left lower quadrant)
• Bloody, loose stools

Paralytic phase

• Pain more diffuse
• Bowel sounds become absent.
• Bloating
• Bloody stools cease

Shock phase

• Acute abdomen with abdominal guarding and rebound tenderness
• Signs of septic shock

Question 18

What arteries are often implicated in ischaemic colitis?

Answer 18

• SMA
• IMA

Question 19

What are signs of ischaemic colitis?

Answer 19

Distended and tender abdomen

Question 20

What investigations would you consider doing in someone with suspected ischaemic colitis?

Answer 20

• Bloods - ABG, CK, FBC
• AXR - to exclude other disorders
• Consider Colonoscopy
• Exploratory laparotomy

Question 21

What is the following?

Answer 21

Thumb print sign - a radiographic sign of large bowel wall thickening, usually caused by oedema, related to an infective or inflammatory process (colitis). It can be seen in ischaemic colitis

Question 22

How would you manage someone with ischaemic colitis?

Answer 22

Conservative

• Supportive care - IV fluids, bowel rest, nasogastric tube in case of an ileus
• Antiplatelet drugs
• Reduce risk of atherosclerosis
• Severe forms (signs of peritonitis, sepsis): surgical intervention (laparotomy and bowel resection)

Question 23

What complication can commonly develop after an attack of ischaemic colitis?

Answer 23

Ischaemic strictures

Question 24

Where is the most common site for mesenteric ischaemia to occur?

Answer 24

Splenic flexure - watershed between SMA and IMA

Question 25

What is the most common cause of acute mesenteric ischaemia?

Answer 25

Acute arterial embolism - 50% of cases * **AF** * **MI** * **Valvular heart disease** * **Endocarditis**

Question 26

What is the second commonest cause of acute mesenteric iscahemia?

Answer 26

Arterial thrombosis - 25% * **Atherosclerosis** * **Artertitis** * **Aortic aneurysm** * **Dissection**

Question 27

If someone had abrupt onset of acute abdominal pain out of proportion with clinical signs?

Answer 27

Acute mesenteric embolism - Abdominal apoplexy

Question 28

What is the general clinical course of mesenteric ischaemia caused by thrombosis?

Answer 28

Presentation less severe because patients have better collateral supply

Question 29

How does someone with mesenteric ischaemia caused by embolism present?

Answer 29

Abrupt onset * **Severe abdominal pain** * **Fever** * **Bloody diarrhea** * **Leukocytosis** * **Atrial fibrillation**

Question 30

What would you want to ask about in PMH in someone with suspected ischaemic bowel/mesentery?

Answer 30

* **AF** * **CVS disease** * **PVD** * **Symptoms of chronic mesenteric ischaemia**