Intestinal obstruction - Small bowel obstruction

Question 1

Definition

Answer 1

Mechanical or functional obstruction of the small intestine that prevents the normal passage of digestive contents

Question 2

Risk factors/Aetiology

Answer 2

PREVIOUS ABDOMINAL SURGERY
ADHESIONS (MC) often surgical
Crohn’s disease
Strangulating Hernia
Appendicitis
Intestinal malignancy
Intussusception
Volvulus
Gallstones

Question 3

Pathophysiology

Answer 3

Obstruction of the bowel leads to distension above the blockage due to a build up of fluid + contents
This causes increased pressure which pushes on the bowel wall blood vessels causing them to become compressed cannot therefore supply blood resulting in ischaemia + necrosis + eventually perforation

Question 4

Signs

Answer 4

Abdominal tenderness and distension
TINKLING BOWEL SOUNDS (absent bowel sounds may be present in paralytic ileus)
Hyper resonant bowels on percussion in both SBO/LBO
Rectal examination - blood suggests strangulation + ischaemia
Tachycardia + hypotension

Question 5

Symptoms

Answer 5

Colicky, central or generalised abdo pain
FIRST VOMITING THEN CONSTIPATION
Mild abdominal distension + pain

Question 6

Diagnosis

Answer 6

FIRST LINE = X ray = dilated bowel loops + transluminal fluid-gas shadows (fluid + air accumulates in bowels here = good diagnostic sign for SBO/LBO
GOLD STANDARD = WITH contrast CT abdo

Question 7

Treatment

Answer 7

FIRST LINE = DRIP (IV fluids) and SUCK (NG tube)
Anti-emetics + analgesia
Abx “stasis is the basis” (increased infection risk)
- CEFOTAXIME + METRONIDAZOLE
Surgery last resort = emergency laparotomy

Question 8

Compilations

Answer 8

Bowel ischaemia + perforation
Sepsis
Aspiration pneumonia
Short gut syndrome