FN: Bowel obstruction Cause and Investigations Flashcards Preview

Final Notes > FN: Bowel obstruction Cause and Investigations > Flashcards

Flashcards in FN: Bowel obstruction Cause and Investigations Deck (17):
1

Classification

simple
Closed loop
Strangulated

2

Simple

1 obstructing point + no vascular compromise
May be partial or complete

3

Closed loop

Bowel obstructed @ two points
- left CRC with competent ileocaecal valve
- volvulus

Gross distension - perforation

4

Strngulated

Compromised blood supply
Localised, constant pain + peritonism
Fever + WCC raised

5

Common Causes

SBO: adhesions or hernias
LBO: colorectal neoplasia, diverticular disease, volvulus

6

Other causes: non mechanical

Paralytic ileus
1. Post-op
2. peritonitis
3. Pancreatitis or any localised inflammation
4. Poisons/Drugs: anti-ACMM (e.g.s TCAs)
Pseudo-obstruction
Metabolic: reduced K, reduced Na, reduced Mg, uraemia
Mesenteric ischaemia

7

Mechanical causes

Intraluminal:
Intramural
Extramural

8

Intraluminal

Impacted matter: faeces, worms, bezoars
Intussusception
gallstones

9

Intramural

Bening stricture: IBD, surgery, Ischaemic collitis, Diverticultis, radiotherapy

Neoplasia
Congenital atresia

10

Extramural

Hernia
Adhesions
Volvulus (sigmoid, caecal, gastric)
Extrinsic Compression:
1. Pseudocyst
2. Abscess
3. Haematoma
4. Tumour e.g. ovarian
5. Congenital bands (e.g. Ladds)

11

Presentation

Abdominal pain
distension - increased w/ lower obstructions
Vomiting
Absolute Constipation

12

Abdominal pain

Colicky
Central but level depends on gut region
Constant/ localised pain suggests strangulation or impending perforation

13

Examiantion

raised HR: hypovolaemia, strangulation
2. Dehydration, hypovolaemia
3. Fever: suggest inflammatory disease or strangulation
4. Surgical scares
5. Hernias
6. Mass: neoplastic or inflammatory
7. Bowel sounds
a. mechanical obstruction
b. Ileus
8. PR
a. Empty rectum
b. rectal mass
c. hard impacted stool
d. Blood from higher pathology

14

Investigations

Bloods
Imaging
Gastrogaffin studies
Colonoscopy

15

Bloods

FBC: raised WCC
U_E: dehydration, electrolyte ab.
AMylase: raised inf stragulation or perforation
VBG: raised lactate in strangulation
4. G+S clotting: may need surgery

16

Imaging

erect CXR
AXR ! erect film for fluid levels
CT: can show transition point

17

Gastrogaffin studies

Look for mechanical obstruction: no free flow
Follow through or enema
follow through may relieve mild mechanical obstruction usually adhesional

Decks in Final Notes Class (196):