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Assessment
A number of different conditions can cause intestinal obstruction.
Intestinal obstruction may be mechanical or non-mechanical
(paralytic ileus). Attention to hydration with intravenous
fluid resuscitation is vital in all patients with intestinal
obstruction. If the obstruction is not resolved, either by
non-operative or operative treatment, intestinal gangrene or
perforation will occur and lead to peritonitis. Bowel obstruction
presents with:
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Abdominal
pain, which may be colicky |
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Vomiting |
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Obstipation
(absence of bowel movements and flatus) |
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Abdominal
distension. |
Bowel obstruction is a clinical diagnosis but it is greatly
aided by plain erect and supine abdominal X-rays. The normal
small bowel does not contain air and is therefore not visualized
on X-ray. Distended loops of small bowel with air fluid levels
are diagnostic of obstruction. Valvule coniventes cross the
entire small bowel lumen and, when seen on X-ray, also indicate
that the obstruction is intestinal.
Non-operative management of Intestinal
Obstruction
The treatment of simple mechanical small bowel obstruction
is initially non-operative. Failure of non-operative management
at 48 hours is an indication for laparotomy. Non-mechanical
obstruction should be treated non-operatively. However, an
obstruction caused by an underlying problem like abdominal
abscess or generalized peritonitis will require surgery. The
resuscitation procedure in non-operative management prepares
the patient for surgery if it becomes necessary.
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Administer
intravenous fluids, starting with normal saline or Ringer’s
lactate and changing on the basis of serum electrolyte
results. |
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Insert
a nasogastric tube and commence aspirations. |
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Relieve
pain with narcotic analgesics. |
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Monitor
the response to fluids with vital signs and urinary output.
Remember that intestinal obstruction causes dehydration
so relatively large volumes of fluid are required to
assure adequate urine output. |
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Ascertain
from the history, physical examination and plain X-rays
the cause of the obstruction. |
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Observe
the patient’s condition with serial physical examination
to determine whether the obstruction is getting better
or worse. Do this at least two times per day. |
Evidence of improvement includes:
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Reduction
in abdominal distension |
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Reduction
in peristaltic waves (which become less visible) |
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Progressive
reduction in nasogastric aspirates. |
Evidence of deterioration includes:
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Colicky
pain that becomes persistent |
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Rigid,
tender and silent abdomen |
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Increasing
abdominal distension |
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Visible
peristaltic waves. |
Operative Management of Small
Intestinal Obstruction
The operative management of intestinal obstruction is laparotomy,
with specific surgical intervention depending on the findings.
Laparotomy should be performed using a midline incision (see
pages 6–1 to 6–3).
Division of adhesions to release the obstruction is often
the treatment in mechanical small bowel obstruction when
non-operative management has failed. If the small intestine
is not viable (gangrenous) it should be resected and an anastomosis
performed (see pages 6–12 to 6–13).
If the small bowel obstruction is due to inguinal hernia, the
hernia should be repaired (see Unit 8: Abdominal Wall Hernia).
If the small bowel is not viable, it must be resected. If this
cannot easily be done through the groin incision, make a lower
midline incision and perform the resection through the abdominal
approach.
Intestinal gangrene is:
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An
indication for laparotomy and intestinal resection |
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Suspected
when there is continuous abdominal pain |
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Associated
with tachycardia and fever |
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Often
associated with reduced blood pressure (shock is a late
sign) |
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Associated
with abdominal tenderness, guarding and absent bowel
sounds. |
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In small bowel obstruction, pain
is mid-abdominal while in large bowel obstruction the
pain is below the umbilicus
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The more proximal the bowel obstruction, the more frequent
the vomiting
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The more distal the bowel obstruction, the more distended
the abdomen
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For paralytic ileus (non-mechanical obstruction):
– Provide nasogastric suction and intravenous fluids
until gut function returns
– Maintain fluid and electrolyte balance
– Treat the underlying cause.
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In ileus (non-mechanical obstruction):
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Treat the underlying medical cause
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Treat the underlying surgical cause with operation, as
indicated.
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Gangrene is an indication for small bowel resection
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Strangulated hernia and small bowel obstructions from
adhesions can lead to gangrene
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The technique for anastomosis of the small bowel is the
same for all indications.
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