Intestinal Obstruction Flashcards
Describe the general signs and symptoms of small and large bowel obstruction?
LBO:
- No flatus
- No faeces*
- Vomit dependent on the patency of the ileocaecal valve*
- Colicky abdominal pain
- Distension
SBO:
- No flatus
- May pass some faeces initially*
- Bilious vomit
- Colicky abdominal pain
- Distension
Signs: High pitched tinkling bowel sounds Distension Clean glove on PR Dehydration Palpable mass
List the most common causes of large and small bowel obstruction?
Small Bowel:
- Adhesions (treat with drip and suck)
- Hernias
- Strictures (caecal cancer, crohns)
- Paralytic ileus
- Caecal volvulus
Large Bowel:
- Malignancy (usually rectal/sigmoid)
- Crohn’s strictures (less common in UC)
- Diverticular stricture
- Sigmoid Volvulus
- Pseudo-obstruction
What are the complications of bowel obstruction?
If the obstruction is due to Ca it is likely to be advanced and metastatic.
Perforation > peritonitis and sepsis
Strangulation + Bowel Ischaemia
Oedema > Fluid and electrolyte imbalance —> Hypovolaemia > AKI
What investigations should you do in a patient with suspected bowel obstruction?
Fluid Charts should be taken to measure loss.
Routine bloods: include Group and Save and VBG (check lactate), Amylase
Abdominal X ray and erect CXR (diagnostic)
Abdominal CT scan to look for cause.
Describe how you can differentiate between SBO and paralytic ileus?
Paralytic ileus:
- Absent bowel sounds
- Diffuse air-filled levels
SBO:
- Can occur at any time.
- Tinkling bowel sounds
CT will be definitive as there will be no mechanical obstruction present.
What are the signs and symptoms suggestive of strangulation or bowel ischaemia?
What will be abnormal in the FBC and ABG?
Increase in pain + TENDERNESS Increasing NEWS (increased RR, HR, hypotensive etc)
High/rising lactate
Increased WCC
Describe how small bowel obstruction is managed initially and definitively?
Initial management:
- Pain relief (10mg in 10ml Morphine and titrate to response)
- Antiemetic (not Metaclopramide*) either: Ondasetron or Cyclizine
- NG tube (drain to dryness initially and then 4 hourly)
Definitive treatment:
-If not perforated/ strangulated treat conservatively for 72hrs with ‘drip and suck’ aka NG tube to decompress and IV fluids. (usually resolves)
If doesn’t resolve/ if perforation or strangulation has developed:
-Adhesions: may need adhesiolysis
-Hernia: surgical repair
-Stricture: surgical management
-IBD: sterioids
Describe how large bowel obstruction is managed?
Initial management is the same as SBO.
Definitive management:
- Colorectal Ca (surgical resection)
- Crohn’s stricture (surgery)
- Volvulus (flatus tube 24h to untwist the bowel)
- Diverticular disease (surgery)
- Pseudo-obstruction (DO NOT OPERATE)
Describe the specific management of a colorectal cancer causing a LBO?
Hartman’s procedure aka cancer resection, create a colostomy usually on the left and leave a rectal stump.
Colostomy can be reversed at a later date.
What are the 2 types of volvulus and how can you differentiate between them?
Sigmoid volvulus: much more common
Caecal volvulus: usually only occurs in the elderly
You can differentiate between them on a plain film XR as sigmoid volvulus will be accompanied by dilation of the large bowel as the obstruction is distal.
What is faecal impaction?
A solid, immobile bulk of faeces that can develop in the rectum as a result of chronic constipation.
Describe how faecal impaction is diagnosed and managed?
History.
PR will show hard stool.
AXR: will show impacted stool.
Management:
Osmotic laxatives to soften the stool.
Manual evacuation.
Enema.
Which types of obstruction are most likely to strangulate
Hernias, volvulus
Which part of the bowel is most likely to perforate
The caecum
Name causes of paralytic ileus
- Post surgery (normal up to 4 days)
- Pancreatitis/cholecystitis (due to inflammation)
- Opiates
- Pseudo-obstruction (caused by DKA, extreme hypothyroid, electrolyte disturbances, stroke, AKI, trauma,)
