INTESTINAL OBSTRUCTION
Fadi J. Zaben RN MSN
Overview:
The small intestine and colon are components of digestive tract, which
processes the foods what we eat.
The small intestine and colon extract nutrients from the foods. What isn't
absorbed by the small intestine and colon continues along the digestive
tract and is expelled as stool during a bowel movement.
Definition:
Intestinal obstruction occurs when the passage of
intestinal contents through the lumen is impaired.
Intestinal obstruction is an interruption in the
normal flow of intestinal contents along the
intestinal tract.
The block may occur in the small or large intestine,
may be complete or incomplete, may be mechanical
or paralytic, and may or may not compromise the
vascular supply.
Obstruction most frequently occurs in the young
and the old.
Bowel obstruction can occur in both the small and
large bowel.
The small bowel is most commonly affected, with
the ileum as the most common site of obstruction.
Large bowel obstruction accounts for only 15% of
cases of bowel obstruction and the sigmoid colon
is the most common site of obstruction.
The location of the obstruction, the degree of
obstruction, and the presence of ischemia are
important distinctions because treatment varies.
Types of Intestinal Obstruction:
1. Mechanical obstruction.
2. Paralytic (adynamic, neurogenic) ileus.
3. Strangulation obstruction.
Mechanical obstruction:
• It is a physical block to passage of intestinal
contents without disturbing blood supply of
bowel.
• High small-bowel (jejunal) or low small-bowel
(ileal) obstruction occurs four times more
frequently than colonic.
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Caused by:
1. Extrinsic adhesions: from surgery, hernia, wound
dehiscence, masses, volvulus (twisted loop of intestine).
Up to 70% of small bowel obstructions are caused by
adhesions.
2. Intrinsic: hematoma, tumor, intussusception
(telescoping of intestinal wall into itself), stricture or
stenosis, congenital (atresia, imperforate anus), trauma,
inflammatory diseases (Crohn's, diverticulitis, ulcerative
colitis)
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3. Intraluminal: foreign body, fecal or barium
impaction, polyp, gallstones, meconium in
infants
4. In postoperative patients, approximately 90%
of mechanical obstructions are due to
adhesions. In nonsurgical patients, hernia (most
often inguinal) is the most common cause of
mechanical obstruction.
Paralytic (adynamic, neurogenic) ileus:
• Peristalsis is ineffective (diminished motor
activity perhaps because of toxic or traumatic
disturbance of the autonomic nervous system).
• There is no physical obstruction and no
interrupted blood supply.
• Disappears spontaneously after 2 to 3 days.
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• Causes include:
Spinal cord injuries; vertebral fractures.
Postoperatively after any abdominal surgery.
Peritonitis, pneumonia.
Wound dehiscence (breakdown).
GI tract surgery.
Strangulation Obstruction:
• It compromises blood supply, leading to
gangrene of the intestinal wall.
• Caused by prolonged mechanical obstruction.
Altered Physiology:
1. Increased peristalsis, distention by fluid and gas, and increased
bacterial growth proximal to obstruction. The intestine
empties distally.
2. Increased secretions into the intestine are associated with
diminution in the bowel's absorptive capacity.
3. The accumulation of gases, secretions, and oral intake above
the obstruction causes increasing intraluminal pressure.
4. Venous pressure in the affected area increases, and circulatory
stasis and edema result.
5. Bowel necrosis may occur because of anoxia and compression
of the terminal branches of the mesenteric artery.
6. Bacteria and toxins pass across the intestinal membranes into
the abdominal cavity, thereby leading to peritonitis.
7. Closed-loop obstruction is a condition in which the intestinal
segment is occluded at both ends, preventing either the
downward passage or the regurgitation of intestinal contents.
Risk Factors:
• Diseases and conditions that can increase risk of
intestinal obstruction include:
 Abdominal or pelvic surgery, which often causes
adhesions.
Crohn's disease.
 Cancer within your abdomen, especially if their a
surgery to remove an abdominal tumor or
radiation therapy.
Clinical Manifestations:
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Abdominal distention.
Abdominal fullness, gas.
Abdominal pain and cramping.
Breath odor.
Constipation.
Diarrhea.
Vomiting.
Fever, peritoneal irritation, increased WBC count,
toxicity, and shock may develop with all types of
intestinal obstruction.
Tests and Diagnosis:
• Physical exam.
• Fecal material aspiration from NG tube
• Abdominal and chest X-rays:
1. May show presence and location of small or large
intestinal distention, gas or fluid.
2. Bird beak lesion in colonic volvulus.
3. Foreign body visualization.
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• Contrast Studies:
 Barium enema may diagnose colon obstruction or
intussusception.
 Ileus may be identified by oral barium or Gastrografin.
• Laboratory Tests:
 May show decreased sodium, potassium, and chloride levels
due to vomiting.
 Elevated WBC counts due to inflammation; marked increase
with necrosis, strangulation, or peritonitis.
 Serum amylase may be elevated from irritation of the pancreas
by the bowel loop.
• Flexible sigmoidoscopy or colonoscopy may identify the
source of the obstruction such as tumor or stricture.
Treatment:
1. Nonsurgical Management.
2. Surgery.
Nonsurgical Management:
1) Correction of fluid and electrolyte imbalances with
normal saline or Ringer's solution with potassium as
required.
2) NG suction to decompress bowel.
3) TPN may be necessary to correct protein deficiency
from chronic obstruction, paralytic ileus, or infection.
4) Analgesics and sedatives, avoiding opiates due to GI
motility inhibition.
5) Antibiotics to prevent or treat infection.
6) Ambulation for patients with paralytic ileus to
encourage return of peristalsis.
Surgery:
• Consists of relieving obstruction. Options
include:
Closed bowel procedures: lysis of adhesions,
reduction of volvulus, intussusception, or
incarcerated hernia
Enterotomy for removal of foreign bodies.
Resection of bowel for obstructing lesions, or
strangulated bowel with end-to-end anastomosis
Intestinal bypass around obstruction
Temporary ostomy may be indicated.
Complications:
Dehydration due to loss of water, sodium, and
chloride.
Peritonitis.
Shock due to loss of electrolytes and dehydration.
Death due to shock.
Nursing Assessment:
1. Assess the nature and location of the
patient's pain, the presence or absence of
distention, flatus, defecation, emesis,
obstipation.
2. Listen for high-pitched bowel sounds,
peristaltic rushes, or absence of bowel
sounds.
3. Assess vital signs.
Nursing Diagnoses:
1. Acute Pain related to obstruction, distention, and
strangulation.
2. Risk for Deficient Fluid Volume related to impaired
fluid intake, vomiting, and diarrhea from intestinal
obstruction.
3. Diarrhea related to obstruction.
4. Ineffective Breathing Pattern related to abdominal
distention, interfering with normal lung expansion.
5. Risk for Injury related to complications and severity
of illness.
6. Fear related to life-threatening symptoms of
intestinal obstruction.
Nursing Interventions:
Achieving Pain Relief:
Administer prescribed analgesics.
Provide supportive care during NG intubation to
assist with discomfort.
To relieve air-fluid lock syndrome, turn the patient
from supine to prone position every 10 minutes
until enough flatus is passed to decompress the
abdomen.
A rectal tube may be indicated.
Maintaining Electrolyte and Fluid Balance:
Measure and record all intake and output.
Administer I.V. fluids and parenteral nutrition as
prescribed.
Monitor electrolytes, urinalysis, hemoglobin, and
blood cell counts, and report any abnormalities.
Monitor urine output to assess renal function and
to detect urine retention due to bladder
compressions by the distended intestine.
Monitor vital signs; a drop in BP may indicate
decreased circulatory volume due to blood loss
from strangulated hernia.
Maintaining Normal Bowel Elimination:
Collect stool samples to test for occult blood if
ordered.
Maintain adequate fluid balance.
Record amount and consistency of stools.
Maintain NG tube as prescribed to decompress
bowel.
Maintaining Proper Lung Ventilation:
• Keep the patient in Fowler's position to
promote ventilation and relieve abdominal
distention.
• Monitor ABG levels for oxygenation levels if
ordered.
Preventing Injury Due to Complications:
Prevent infarction by carefully assessing the
patient's status; pain that increases in intensity or
becomes localized or continuous may herald
strangulation.
Detect early signs of peritonitis to minimize this
complication.
Avoid enemas, which may distort an X-ray or
make a partial obstruction worse.
Observe for signs of shock.
Watch for signs of (metabolic alkalosis and
metabolic acidosis.