8. Pathophysiology
• Bowel distal to obstruction collapse
• Bowel proximal to obstruction distends and becomes hyperactive
(distension due to intestinal secretions and swallowed air)
• Bowel wall becomes edematous. Fluid electrolytes accumulate in
the wall and lumen (third space loss)
• Bacteria proliferate in the obstructed bowel
• As the bowel distends, intramural vessels become
stretched/compromised
• Ischemia and necrosis
10. • Pain
• Small bowel :
- periumbilical and colicky
- comes in spasm
- builds up in crescendo
- then tappers off
- regular pain at intervals of 2-3 minutes
• Large bowel : below the umbilicus & comes at intervals
of 6-10 minutes.
• Severe & continuous pain suggest strangulation
obstruction.
11. • Vomiting
• The higher the obstruction, the vomiting is more
severe
• In large bowel obstruction vomiting comes later and
sometimes patient may not vomit at all.
• As obstruction progresses the character of the vomitus
alters (digested food feculent material; as a result
of the presence of enteric bacterial overgrowth)
12. • Abdominal distention
• The more distal the obstruction, the more distention
of abdomen.
• Visible peristalsis may be present.
• Constipation
• May pass feces or flatus if early onset
• Occurs early in lower large bowel obstruction
• Occurs late in high small bowel obstruction
• Absolute constipation is a feature of complete
intestinal obstruction.
13. • In high small bowel obstruction,
vomiting occurs early and is profuse with rapid
dehydration. Distension is minimal
• In low small bowel obstruction,
Vomiting is delayed. pain is predominant with central
distension.
• In large bowel obstruction,
distension is early and pronounced. Pain is mild and
vomiting and dehydration are late.
14. Inspection
• Visible scar -band
-adhesion
Palpation
• hernial orifices
• large, slightly tender,
mobile
• mass changes its position
with colicky pain
• tender indurated mass
• hard impacted masses
-incarcerated
-strangulated hernia
+torsion
+intussusception
-mass of Ascaris worms
+intraperitoneal abscess
-fecaloma
15. Percussion - tympanic sound
Auscultation -runs of borborygmi
-tinkling high pitched musical
sounds
Rectal examination
• fresh blood and mucus
• hard mass of faeces
• hard mass in the
rectovesical pouch
-strangulating lesion
-carcinoma of large gut
-intussusception
+constipation
-extraintestinal tumour
17. • Radiological
• AXR
• Gas pattern
• Fluid level
• Masses shadow
• Fecal pattern
• Chest X-Ray
• Elevated diaphragm
• Air under diaphragm
• Aspiration
18. • USG:
• to differentiate mechanical obstruction & paralytic ileus,
• poor visualization of gas filled structure,
• only useful in selected patient ie pregnant, when CT is
contraindicated, in critically ill patients
• Free fluid
• Masses
• Mucosal folds
• Pattern of peristalsis
• CT scan:
• level of obstruction (transition point)
• Causes (hernias, inflammatory changes, masses)
• sign of strangulation, ischemia, perforation
19. Large Bowel: Small Bowel:
•Peripheral
•Presence of haustration, diameter
>8 cm
•distended caecum a rounded gas
shadow in the right iliac fossa. >10cm
diameter.
•Central
•jejunum valvulae conniventes
•Ileum featureless
•Diameter >5 cm
•No gas is seen in the colon
20. Pseudo-obstruction
DEFINITION
• Describes an obstruction that occurs in the absence of
mechanical cause or acute intra abdominal disease
• Diagnosis of exclusion in the absence of mechanical cause
CAUSES
• Idiopathic
• Metabolic
• Severe trauma
• Shock
• Septicaemic
• Retroperitoneal irritation
• Drugs
21. Ogilvie’s Syndrome
• Acute large bowel obstruction
• Absence of mechanical cause
• AXR – evidence of colonic obstruction, usually marked cecal
distension
• Single contrast water soluble barium enema, CT scan and
colonoscopy can be done
• Once diagnosis confirmed, treat with colonoscopic decompression
• Recurrence occurs in 25%
• Complication – cecal perforation
• Repeat colonoscopy with simultaneous placement of flatus tube
may be required
• Surgical intervention – subtotal colectomy and ileorectal
anastomosis
22. Principles of Treatment
• Gastrointestinal drainage
• Fluid and electrolytes replacement
• Relief of obstruction
• Surgical intervention
• necessary for most cases
• Need to be delayed until resuscitation is complete
23. Early Management
• ABC
• Resuscitation
• Oxygen supply
• fluid replacement with hartman or normal saline
• Nasogastric decompression
• KNBM
• NG tube with free flow or 4hly aspirate
• Close monitoring
• BP, PR, Temp, Input/output, CVP
• Antibiotic s cover
• Analgesia
24. Indication For Surgery
• Immediate intervention
• Evidence of strangulation
• Signs of peritonitis resulting from perforation or ischemia
• In the next 24-48H
• Clear indication of no resolution of obstruction (clinical or
radiological)
• Diagnosis is unclear in virgin abdomen
25. Take Home Message
• 4 cardinal signs of intestinal obstruction are abdominal pain,
abdominal distension, vomiting and constipation
• Pseudo-obstruction is the diagnosis of exclusion in the
absence of mechanical obstruction
• Decompress the obstructed gut (NGT!!)
26. • Replace fluid and electrolytes loses
• Strict IO (CBD is least, CVP - especially in elderly, immuno
compromised patient)
• CT if only patient is stable and cause of obstruction is unclear
• Surgical intervention promptly if signs of peritonitis or
strangulation, underlying cause needs surgical treatment ie
colonic carcinoma or hernias or patient does not improve with
conservative treatment
Partial intestinal obstruction
Abdominal Distention,Presence of flatus, Presence of bowel movement
Complete Intestinal Obstruction
cardinal signs of intestinal plus a collapsed rectal vault
Summary box 66.10
Radiological features of obstruction
■ The obstructed small bowel is characterised by straight
segments that are generally central and lie transversely. No
gas is seen in the colon
■ The jejunum is characterised by its valvulae conniventes,
which completely pass across the width of the bowel and
are regularly spaced, giving a ‘concertina’ or ladder effect
■ Ileum – the distal ileum has been piquantly described by
Wangensteen as featureless
■ Caecum – a distended caecum is shown by a rounded gas
shadow in the right iliac fossa
■ Large bowel, except for the caecum, shows haustral folds,
which, unlike valvulae conniventes, are spaced irregularly,
do not cross the whole diameter of the bowel and do not
have indentations placed opposite one another
Delayed for surgical intervention provided no sign of strangulation or close loop obstruction