Bowel ischaemia Flashcards
What are the 3 main types of bowel ischaemia?
- Acute mesenteric ischaemia
- Chronic mesenteric ischaemia
- Ischaemic colitis/Chronic colonic ischaemia
What is acute mesenteric ischaemia?
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
What are causes of acute mesenteric ischaemia?
- SMA thrombosis/embolism
- AF
- Mesenteric vein Thrombosis
- Low flow states - heart failure
- Trauma
- VAsculitis
- Radiotherapy
- Strangulation
How do those with acute mesenteric ischaemia tend to present?
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
If you suspected acute mesenteric ischaemia, what investigations would you consider doing?
- Bloods - FBC, U+E’s, ABG
- ECR
- Erect CXR
- AXR
- CT/MR angiography/Formal arteriography
What might you see on FBC in someone with acute mesenteric ischaemia?
- Increased Hb - due to increased plasma loss
- Increased WCC
What might you see on U+E’s in someone with acute mesenteric ischaemia?
- Uraemia
- Elevated creatinine
What might you see on ABG in someone with acute mesenteric ischaemia?
- Acidosis
- Elevated lactate
What might you find on ECG in someone with acute mesenteric ischaemia?
Indication of cause
- AF
- Arrhythmia
- ACute MI
What might you find on AXR in someone with suspected acute mesenteric ischaemia?
May inidicate aetiology
- Air fluid levels
- Bowel dilation
- Bowel wall thickening
- Pneumatosis
How would you manage someone with acute mesenteric ischaemia?
ABCDE
- Supportive - NG tube, Fluid resiscitation, Antibiotics
- LMWH - cases of venous thrombosis
- Consider Local thrombolytics
-
Surgical
- Revascularisation
- Resection
What are life-threatening complications of acute mesenteric ischaemia?
- Septic peritonitis
- SIRS
- Multi-organ failure
What are features of chronic mesenteric ischaemia?
Triad of:
- Severe colicky, post-prandial abdominal pain - ‘gut cluadication’
- Weight loss - eating hurts
- Upper abdominal bruit
May also have
- Bloating
- PR bleeding
- Malabsorption
- Nausea + Vomiting
What tests would you do if you suspected chronic mesenteric ischaemia?
CT angiography/Contrast enhanced MR angiography
How would you manage someone with chronic mesenteric ischaemia?
- Percutaneous transluminal angioplasty + stent insertion
- Consider open revascularisation - not really used anymore
What is chronic mesenteric ischaemia also known as?
Intestinal angina
What are symptoms of ischaemic colitis?
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
What arteries are often implicated in ischaemic colitis?
- SMA
- IMA
What are signs of ischaemic colitis?
Distended and tender abdomen
What investigations would you consider doing in someone with suspected ischaemic colitis?
- Bloods - ABG, CK, FBC
- AXR - to exclude other disorders
- Consider Colonoscopy
- Exploratory laparotomy
What is the following?
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
How would you manage someone with ischaemic colitis?
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)
What complication can commonly develop after an attack of ischaemic colitis?
Ischaemic strictures
Where is the most common site for mesenteric ischaemia to occur?
Splenic flexure - watershed between SMA and IMA
What is the most common cause of acute mesenteric ischaemia?
Acute arterial embolism - 50% of cases
- AF
- MI
- Valvular heart disease
- Endocarditis
What is the second commonest cause of acute mesenteric iscahemia?
Arterial thrombosis - 25%
- Atherosclerosis
- Artertitis
- Aortic aneurysm
- Dissection
If someone had abrupt onset of acute abdominal pain out of proportion with clinical signs?
Acute mesenteric embolism - Abdominal apoplexy
What is the general clinical course of mesenteric ischaemia caused by thrombosis?
Presentation less severe because patients have better collateral supply
How does someone with mesenteric ischaemia caused by embolism present?
Abrupt onset
- Severe abdominal pain
- Fever
- Bloody diarrhea
- Leukocytosis
- Atrial fibrillation
What would you want to ask about in PMH in someone with suspected ischaemic bowel/mesentery?
- AF
- CVS disease
- PVD
- Symptoms of chronic mesenteric ischaemia
