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65 Cards in this Set

  • Front
  • Back
What is mechanical obstruction?
bowel is physically obstructed by disorders outside the intestine
ex: adhesions or hernias
or by blockage in the lumen of the intestine
ex: tumors, inflammation,
strictures, fecal
What is nonmechanical obstruction?
(also known as paralytic ileus or adynamic ileus because it is a result of neuromuscular disturbance)

it is decreased or absent which results in a slowing of
the movement or a backup of intestinal contents
does not involve a physical obstruction in or outside the intestine...what happens to peristalsis?
What are intestinal contents composed of?
ingested fluid and saliva

gastric, pancreatic, and biliary secretions

swallowed air
In mechanical and nonmechanical obstructions, where do the intestinal contents accumulate?
at and above the area of obstruction
How does intestinal distention result?

by increasing the effort to move the intestinal contents forward...what does increased peristalsis stimulate?

edema of the bowel with increased capillary permeability....there is plasma leaking into the peritoneal cavity and where is fluid trapped?

there is reduced circulatory blood volume and electrolyte imbalances, called HYPOVOLEMIA!
(if not dealt with, renal
insufficiency then death
can occur)
from the intestine's inability to absorb the contents and mobilize them down the intestinal does peristalsis compensate for the lag?

more secretions, which leads to additional distention...what does this create in the bowel?

in intestinal lumen which markedly decreases the absorption of fluid and electrolyte into the vascular space...then what typically occurs?
The type of f&e loss depends on what?
which part of intestine is blocked
If the obstruction occurs high in the small intestine, what happens?
there is a loss of gastric hydrochloride, which can lead to METABOLIC ALKALOSIS.
Obstruction below the duodenum but have the large bowel results in?
loss of both acids and bases, so that acid-base imbalance is usually not compromised
Obstruction at the end of the small intestine and lower intestinal tract causes?
loss of slkaline fluids, which can lead to METABOLIC ACIDOSIS
What is a closed-loop obstruction?

peritonitis...why does this occur?

because bacteria without blood supply form an endotoxin...and this endotoxin is released into the peritoneal of systemic circulation which results in septic shock

(same for strangulated obstruction)
blockage in two different areas and what is patient at great risk for?

because bacteria lie stagnant in the obstructed intestine which is not a problem until blood flow to the intestine is compromised...why does that make a difference?
What is a strangulated obstruction?

peritonitis...why does this occur?

because bacteria without blood supply form an endotoxin...and this endotoxin is released into the peritoneal of systemic circulation which results in septic shock

(same for closed-loop obstruction)
obstruction with compromised blood flow...and what is patient at great risk for?

because bacteria lie stagnant in the obstructed intestine which is not a problem until blood flow to the intestine is compromised...why does that make a difference?
What is the most common site for bowel obstruction and why?
ileum because it's the narrowest part of the small intestine
Mechanical obstruction can result from?
fecal impactions (esp elders)
strictures due to Crohn's
disease or radiation
intussusception (telescoping
of a segment of the
intestine within self
volvulus (twisting of
fibrosis due to disorders
such as endometriosis
vascular disorders
ex: emboli and arterio-
scerlotic narrowing
of mesenteric vessels
What are the most common causes of obstruction in age 65 and older?
What are the most common cause of mechanical obstruction regardless of age?
adhesions in about 45% to 60%
of cases
<What are adhesions?>
bands of granulation and scar tissue that develop as <a result of an inflammatory response, encircling the intestine and constricting its lumen>
What is paralytic or adynamic ileus?

following abdominal surgery or trauma because of handling of the intestines during abdominal surgery...intestinal function lost for a few hours to a few days
a nonmechanical obstruction caused by physiologic, neurogenic, or chemical imbalances associated with decreased peristalsis from trauma or effect of a toxin on autonomic intestinal control...can occur to some degree when and why?
What thoracic diseases can cause paralytic ileus?
rib fractures
Which "kalemia" can especially predispose patient to ileus?
Why can paralytic ileus be a consequence of peritonitis?
because leakage of colonic contents causes severe irritation and triggers inflammatory response
What is intestinal ischemia?
vascular insufficiency to the bowel which is a potential cause of adynamic ileus
How can heaert failure or severe shock affect intestines?
vascular insufficiency can occur because there is arterial and venous thrombosis or an embolus which decreases blood flow to the mesenteric blood vessels surrounding the intestines...severe insufficiency of blood supply can result in infarction of surrounding organs
What is the most common reason for surgery of the small intestine?
In adults, what percentage of all obstructions occur in the small intestine?
In adults, what percentage of all obstructions occur in the large intestine?
What type of questions should the nurse ask regarding assessment?
past or recent abdominal
radiation therapy
history of inflammatory
bowel disease

nausea or vomiting?
bowel movement time,
character, and consistency
hiccups (singultus)
family history of colorectal
cancer (CRC)?
ask about blood in the stool
or a change in bowel

temperature rarely greater
than 100F...if it's
higher, with or without
guarding and tenderness,
and there is a sustained
in pulse, it could indicate
a strangulated obstruction
or peritonitis
<What is obstipation?>
<no passage of stool
(which may accompany complete obstruction)>
What symptoms does the patient with mechanical obstruction in small intestine often have?
mid-abdominal pain or
pain can be sporadic and
then he'll be comfortable
between episodes
What kind of pain might a patient with strangulated obstruction have?
pain becomes more localized and steady
When might vomiting occur?

may contain bile and mucus or be orange-brown and foul
smelling as a result of
bacterial overgrowth with low ilial obstruction
when obstruction occurs in the proximal small intestine...and what might the vomitus look like?
How does the older client present with strangulated hernia?
may not complain of pain, but instead may only present with n&v...may require surgery
How does mechanical colonic obstruction differ from small bowel obstruction?
m.c.o. causes a milder, more intermittent colicky abdominal pain...lower abdominal distention may be present, as well as obstipation, or ribbon-like stools if obstruction is partial
<Strangulated obstructions result from?>
vascular disorder
fecal in??
<Clinical manifestations of mechanical obstruction are?>
<midabdominal pain or
alteration if bowel
pattern and stool
abdominal distention
abdominal tenderness>
<Clinical manifestations of
nonmechanical obstruction
<constant diffuse discomfort
abdominal distention
decreased to absent bowel
obstipation (severe
obstruction to the normal
flow of feces through
the bowel)>
How is the pain described in most types of nonmechanical obstruction?
How is the pain characterized if obstruction is due to vascular insufficiency or infarction?
severe and constant
On INSPECTION for nonmechanical obstruction, what might the abdomen look like?
abdominal distention
On AUSCULTATION, the abdominal bowel sounds might be?
decreased in early obstruction and absent in later stages
Explain vomiting in nonmechanical obstruction?
vomiting of gastric contents and bile is frequent, but vomitus rarely has foul odor and is rarely profuse.
true or false?
There is no definitive lab test to confirm a diagnosis of mechanical or nonmechanical obstruction?
WBC is probably normal unless
there is?
Elevataed h&h, creatinine, and BUN probably indicate?
Serum electrolytes are reduced because?
loss of fluid and electrolytes
High obstruction in small intestine is likely to show an elevated serum venous carbon dioxide concentration indicating?
metabolic acidosis
Why is a nasogastric tube usually placed in bowel obstructed patients?
provides decompression of bowel by draining fluid and air
How often should the NG tube be assessed for proper placement?
every 4 hours

(also monitor nasal skin daily)
If the NG tube is repositioned or replaced, confirmation of proper placement is obtained by?

(and then be sure to aspirate and irrigate with 30 mL of NS every 4 hours or as needed)
Because of fluid loss and electrolyte loss and NPO status, patient should have?
IV hookup
What measures of fluid status should be assessed that might indicate possible third-spacing (peritonitis for example)?
urine output
skin turgor
mucous membranes
What center in the brain is commonly stimulated in a bowel obstruction patient? ice chips are okay if doctor says patient may be having impending surgery
What might be happening if the pain associated with bowel obstruction goes from colicky, crampy pain to constant discomfort?
perforation of intestine or continually assess where pain is coming from because it can come from being thirsty, vomiting, obstruction itself, dry mucous membranes, etcet.
Opioid analgesics are not commonly given because?
they can mask perforation or peritonitis...and they can slow motility and may cause let family know
Differentiate between what is causing nausea and vomiting because?
it may be poor positioning of NG tube or it may be some type of analgesic/medication causing it
An intervention for helping increase peristalsis is to?

alleviates pressure of abdominal distention on chest; facilitates adequate thoracic excursion and normal breathing patterns
perform frequent position changes...including semi-Fowlers position...which does what?
<Drug therapy for bowel obstruction may include which type of drugs?>
<broad-spectrum IV antibiotics
and something to enhance gastric motility (Sandostatin)>
What type of surgical procedure may be performed?
exploratory laparotomy
The primary preop procedure performed prior to exploratory laparotomy is?
NG tube insertion if indicated
What does surgeon do if obstruction is caused by adhesions?
they're cut (lysed)
What does the surgeon do if obstruction caused by tumor or diverticulitis?
performs colon resection with primary anastomosis or temporary or permanent colostomy
What does surgeon do if obstruction caused by intestinal infarction?
resection of gangrenous
How long does the NG tube stay in following surgery?

peristalis must be assessed over clamp tube for a while, and assess at certain stages to make sure peristalsis is occurring without decompression
until peristalsis returns...but the NG tube removal is gradual because?
If the patient's obstruction was due to fecal impaction, before he goes home, have him demonstrate what?
ability to carry out bowel regimen independently
What health teaching might nurse help client with if he's had mechanical obstruction?
high-fiber diet
fluid intake increase
possible rx for bulk-forming
If the patient had surgery for nonmechanical obstruction, patient teaching includes?
incision care
drug therapy for incisional
discomfort (add stool
activity limitations