Bowel Obstruction Flashcards
Why does bowel obstruction cause vomiting and dilatation of intestines?
Build up of gas causing back-pressure
How does bowel obstruction lead to hypovolaemia and shock?
GI tract secretes fluid that is absorbed in the colon
Obstruction prevents fluid from being reabsorbed
Fluid loss from the intravascular space into GI tract
Third-spacing
Higher up the obstruction the greater the fluid loss
What 3 causes make up 90% of cases of bowel obstruction?
Adhesions (small bowel)
Hernias (small bowel)
Malignancy (large bowel)
What other causes can cause bowel obstruction?
Volvulus
Diverticular disease
Strictures
Intussusception
What are adhesions?
Scar tissue that bind abdominal contents together
Typically cause obstruction in the small bowel
What are the main causes of intestinal adhesions?
Abdominal or pelvic surgery
Peritonitis
Abdominal or pelvic infections
Endometriosis
May be congenital or due to radiotherapy
What is a closed-loop obstruction?
Two points of obstruction along the bowel
May happen with:
- Adhesions
- Hernias
- Volvulus
- Single point obstruction with competent ileocecal valve
Why is a closed-loop obstruction an emergency?
No end in which they may drain and decompress
Continuous expansion leading to ischaemia and perforation
What are the key features of bowel obstruction?
Green bilious vomiting
Abdominal distention
Diffuse abdominal pain
Absolute constipation and lack of flatulence
Tinkling bowel sounds
What is the initial management of bowel obstruction?
Nil by mouth
IV fluids
NG tube with free drainage
What imaging is used in bowel obstruction?
Abdominal x-ray
Erect CXR- looking for air under the diaphragm
Contrast Abdominal CT- can also diagnose any intra-abdominal perforation
What surgical intervention is available for bowel obstruction?
Exploratory surgery
Adhesiolysis
Hernia repair
Emergency resection
Stents
