[20] Pseudo-obstruction Flashcards
What is a pseudo-obstruction also known as in the acute setting?
Oglivie’s syndrome
What is pseudo-obstruction?
A disorder characterised by dilation of the colon due to an adynamic bowel, in the absence of mechanical obstruction
Where does a pseudo-obstruction affect?
It most commonly affects the caecum and ascending colon, however can affect the whole bowel
Is pseudo-obstruction common?
No, it is a rare condition
Who is pseudo-obstruction most common in?
Elderly
By what mechanism does pseudo-obstruction occur?
The exact mechanism is unknown, but it is thought to be due to an interupption of the autonomic nervous supply to the colon, resulting in the absence of smooth muscle action in the bowel wall
What can untreated pseudo-obstruction result in?
An increase in colonic diameter
What can an increased colonic diameter lead to?
Increased risk of toxic megacolon, bowel ischaemia, and perforation
What can cause pseudo-obstruction?
- Electolyte imbalance or endocrine disorders
- Medication
- Recent surgery, severe illness, or trauma
- Recent cardiac event
- Parkinson’s disease
- Hirchsprung’s disease
What electrolyte disturbances can cause pseudo-obstruction?
- Hypercalcaemia
- Hypomagnesia
What endocrine disorder can cause pseudo-obstruction?
Hypothyroidism
What medications can cause pseudo-obstruction?
- Opioids
- Calcium channel blockers
- Anti-depressants
What are the symptoms of pseduo-obstruction?
- Abdominal pain
- Abdominal distention
- Constipation
- Vomiting
Why might a patient with pseudo-obstruction have paradoxical diarrhoea?
Due to adynamic bowel
Why is vomiting typically a late feature in pseudo-obstruction?
Due to the colon being most distal in the GI tract
What may be found on examination in pseudo-obstruction?
- Bowel sounds are often present
- Tympanic abdomen
Why are bowel sounds often present in pseudo-obstruction?
As it is a colon-specific pathology
Why will the abdomen be tympanic in pseudo-obstruction?
Due to distention
Why should you palpate for focal tenderness when examining for pseudo-obstruction?
It indicates ischaemia, and is a key warning sign
Describe the pain experienced on palpation in a patient with pseudo-obstruction
The patient may be uncomfortable on palpation due to discomfort from pressing on a distended abdomen, but there should be no focal tenderness, guarding, or rebound tenderness unless ischaemia is developing
What are the differential diagnoses of pseudo-obstruction?
- Mechanical obstruction
- Paralytic ileus
- Toxic megacolon
What investigations may be done in suspected pseudo-obstruction?
- Wide range of initial blood tests
- Plain abdominal films
- Abdominal-pelvis CT scans
- Motility studies
- Biopsy
