IO

Question 1

4 Cardinal features of IO

Answer 1

Abdo pain
- colicky

Abdo distension
- the more distal the obstruction, the greater the degree of distension

Constipation/obstipation - absolute

Vomiting
- the more distal the obstruction, the longer the interval btw onset of symptoms and appearance of n/v esp if competent ileocaecal valve
- projectile vs bilious vs faecal stained

Dehydration

Bowel sounds
- initially hyperactive and high pitched
- eventually absent

Question 2

Causes of IO

Answer 2

Mechanical

• SBIO: Adhesion, Hernia, Strictures
• LBIO: Cancer, Divert, Sigmoid volvulus

Others
- Impaction
- FB
- Gallstone
- Bezoar

Functional ileus
- Postoperative
- Intraabdominal sepsis
- Metabolic (uraemia, hypokalemia, hypocalcemia)

Question 3

Investigations

Answer 3

FBC
RP - electrolyte derangements

Erect CXR
- free air under the diaphragm TRO perforation

Supine AXR
- dilated bowels (3-6-9)
- visualise the obstruction
- absence/presence of rectal gas

Erect AXR
- air fluid levels
- more pronounced fluid levels > more advanced the obstruction

Question 4

Initial management of IO

Answer 4

Secure airway, breathing, circulation
Escalate to senior

Drip:
- IV fluids
- Correct electrolytes
- IDC to monitor urine output, aim >0.5ml/kg/hr

Suck:
- Keep NBM
- Large bore NGT for decompression
-> aspirate with syringe till dry
-> leave on low intermittent suction
-> q4 hourly aspirate

Adjuncts:
- Analgesia (for abdo pain)
- Anti-emetics (for vomiting)

Question 5

When to suspect closed loop IO?

Answer 5

Imaging/clinical presentation out of expected,
- is it closed loop vs open loop?
- on imaging: when there are dilated large bowels, look for dilated small bowels which indicates incompetence of ileocecal valve

Closed loop IO
- at risk of perforation > surgical emergency
- ask for focal RIF pain (caecum)
*due to Laplace law, caecum is the most common site of perforation in a large bowel IO with a competent ileocaecal valve
- peritonism
- pain out of proportion

+ do lactate > high lactate suggests gut ischemia
+ add abx
+ Do CTAP

Definitive: Surgery