Transcript Lecture Title - Specialists Without Borders

Specialists Without Borders
Seminar in Surgery
Rwanda, September 2010
Differentiating Large Bowel
Obstruction from
Small Bowel Obstruction
David Birks FRACS
September 2010
Darwin
Brisbane
Perth
Adelaide
Victoria
Sydney
Canberra
Melbourne
Hobart
Differentiating large bowel obstruction
from small bowel obstruction
Objectives
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Physiology & anatomy of small/large bowel
Causes of bowel obstruction
Symptoms & signs
Investigations (plain xray)
Complications
Management – conservative & operative
Functions of intestine
• Small intestine – absorption of fluid, food,
vitamins
• Large intestine – absorption of water & Na
- converts 1000-2000ml into
200ml semisolid faeces
Fluid replacement - GI loss
• Type
Na
K
Cl
HCO3
Gastric
100
10
100
Bile
140
5
80
40
Pancreas
140
5
80
100
Small Bowel
90
10
90
30
Fluid replacement - GI loss
• Type
Gastric
Volume
(litres)
2.0
Bile
1.0
Pancreas
1.0
Small bowel
3.5
Total 7.5
Causes of small bowel obstruction
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adhesions (previous operation)
external hernia
small bowel volvulus (primary)
neoplasms
miscellaneous
Causes of large bowel obstruction
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carcinoma of colon
volvulus (sigmoid)
diverticular disease
miscellaneous
Symptoms of bowel obstruction
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abdominal pain
vomiting
distension
constipation (no flatus)
High small bowel obstruction
• frequent, profuse vomiting
• central abdo pain
• minimal distension
Lower small bowel obstruction
• colic pain
• moderate vomiting ( may be faeculent)
• moderate distension
Large bowel obstruction
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abdominal distension
constipation
lower abdo pain ( may be minimal)
minimal vomiting
Physical Examination
• abdo scars
• external hernia
• signs strangulation (tenderness, fever, mass)
Investigations
• Plain Xray – supine
- erect
- chest
• Hb, WCC, Urea & Electrolytes
Further investigations
• CT abdomen
• contrast study (via NG )
Plain x ray SBO
• dilated loops with gas
• centrally placed
• transverse lines (circular folds)
Plain x ray LBO
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dilated bowel with gas (caecum)
peripheral
haustra (not lines across bowel)
may have cut-off point
SBO
Supine
LBO
Prone
Carcinoma of Sigmoid – LBO –
Decompressed into SB
Complications of bowel obstruction
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fluid & electrolyte loss - small bowel
aspiration – small bowel
respiratory restriction– large bowel
strangulation – small bowel
caecal perforation – large bowel (competent
Ileo-caecal valve)
Management of bowel obstruction
• nil orally
• IV fluid & electrolyte replacement
• NasoGastric drainage (small bowel)
Operation for bowel obstruction
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external hernia (SBO) – emergency
signs of strangulation – emergency
SBO not settling – within 24-48 hr
LBO due to carcinoma - soon
Non-operative treatment of bowel
obstruction
• sigmoid volvulus – decompress via
sigmoidoscope
• post-operative SBO
• intussusception in infants (2/12 – 2 yr)
• previous operations for SBO
• radiation
• abdominal carcinomatosis
Operation - SBO
• midline incision
look for ileo-caecal valve
• treat cause
• external hernia – incision over hernia
- if gangrene convert to midline
Operation - LBO
• midline and resect bowel pathology
+/- anastomosis
+/- stoma
• if left sided obstruction – transverse
colostomy through right upper trans incision
Summary of bowel obstruction
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Physiology & anatomy of small/large bowel
Causes of bowel obstruction
Symptoms & signs
Investigations (plain xray)
Complications
Management – conservative & operative
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