GI System 1 Lecture

Learning Objectives:

At the end of this lecture, you will be able to:

1. Describe the structure and function of the organs of the

gastrointestinal tract.

2. Describe the mechanical and chemical processes

involved in digesting and absorbing foods and

eliminating waste products.

JOFRED M. MARTINEZ, RN

3. Use assessment parameters appropriate for

determining the status of gastrointestinal function.

4. Describe the appropriate preparation, teaching, and

follow-up care for patients who are undergoing

diagnostic testing of the gastrointestinal tract.

Learning Objectives (Cont’d.):

Anatomy and Physiology

Anatomy & Physiology

Two groups of organs compose the digestive system:

• GASTROINTESTINAL TRACT include the mouth, most

of the pharynx, esophagus, stomach, small intestine, and

large intestine.

• ACCESSORY DIGESTIVE ORGANS include the teeth,

tongue, salivary glands, liver, gallbladder, and pancreas.








Functions of the digestive system

1. Ingestion: taking food into the mouth.

2. Secretion: release of water, acid, buffers, and enzymes into

the lumen of the GI tract.

3. Mixing and propulsion: churning and propulsion of food

through the GI tract.

4. Digestion: mechanical and chemical breakdown of food.

5. Absorption: passage of digested products from the GI tract

into the blood and lymph.

6. Defecation: the elimination of feces from the GI tract.


• The branch of dentistry that is concerned with the

prevention, diagnosis, and treatment of diseases that

affect the pulp, root, periodontal ligament, and alveolar

bone is known as Endodontics.

• Orthodontics is a branch of dentistry that is concerned

with the prevention and correction of abnormally aligned

teeth.

• Periodontics is a branch of dentistry concerned with the

treatment of abnormal conditions of the tissues

immediately surrounding the teeth, such as gingivitis.






• Mechanical digestion in the mouth results from chewing,

or mastication.

• Salivary amylase, which is secreted by the salivary

glands, initiates the breakdown of starch.

• Lingual lipase, which is secreted by lingual glands in the

tongue. It breaks down dietary triglycerides into fatty acids

and diglycerides.

Mechanical and Chemical Digestion

PHARYNX

• The pharynx, a funnel-shaped tube that extends from the

internal nares to the esophagus posteriorly and to the

larynx anteriorly.

• The pharynx is composed of skeletal muscle and lined by

mucous membrane, and is divided into three parts: the

nasopharynx, the oropharynx, and the laryngopharynx.


ESOPHAGUS

• The esophagus is a collapsible muscular tube, about 25

cm (10 in.) long, that lies posterior to the trachea. The

esophagus begins at the inferior end of the

laryngopharynx and passes through the mediastinum

anterior to the vertebral column.

• Then it pierces the diaphragm through an opening called

the esophageal hiatus, and ends in the superior portion

of the stomach.


• The mucosa of the esophagus consists of nonkeratinized

stratified squamous epithelium, lamina propria, and a

muscularis muscosae.

• At each end of the esophagus, the muscularis becomes

slightly more prominent and forms two sphincters—the

upper esophageal sphincter

• (UES), which consists of skeletal muscle, and the lower

esophageal sphincter (LES), which consists of smooth

muscle.


DEGLUTITION

Swallowing occurs in three stages:

• the voluntary stage, in which the bolus is passed into

the oropharynx

• the pharyngeal stage, the involuntary passage of the

bolus through the pharynx into the esophagus

• the esophageal stage, the involuntary passage of the

bolus through the esophagus into the stomach




Anatomy of the Stomach

Anatomy of the Stomach

FUNCTIONS OF THE STOMACH

1. Mixes saliva, food, and gastric juice to form chyme.

2. Serves as a reservoir for food before release into small

intestine.

3. Secretes gastric juice, which contains HCl, pepsin,

intrinsic factor, and gastric lipase .

4. Secretes gastrin into blood.








BLOOD SUPPLY OF THE LIVER

ROLE AND COMPOSITION OF BILE

• Each day, hepatocytes secrete 800–1000 mL (about 1 qt)

of bile, a yellow, brownish, or olive-green liquid. It has a

pH of 7.6–8.6 and consists mostly of water, bile salts,

cholesterol, a phospholipid called lecithin, bile pigments,

and several ions.

• The principal bile pigment is bilirubin. The phagocytosis

of aged red blood cells liberates iron, globin, and bilirubin.

• One of its breakdown products—stercobilin—gives feces

their normal brown color.


• Bile salts, play a role in emulsification, the breakdown of

large lipid globules into a suspension of small lipid

globules.

• Between meals, after most absorption has occurred, bile

flows into the gallbladder for storage because the

sphincter of the hepatopancreatic ampulla (sphincter

of Oddi) closes off the entrance to the duodenum.


FUNCTIONS OF THE LIVER

• Carbohydrate metabolism.

• Lipid metabolism.

• Protein metabolism.

• Processing of drugs and hormones.

• Excretion of bilirubin.

• Synthesis of bile salts.


FUNCTIONS OF THE LIVER

• Storage for certain vitamins (A, B12, D, E, and K) and

minerals (iron and copper)

• Phagocytosis.

• Activation of vitamin D.



S

Functions of the Small Intestine

1. Segmentations mix chyme with digestive juices and

bring food into contact with the mucosa for absorption;

peristalsis propels chyme through the small intestine.

2. Completes the digestion of carbohydrates, proteins, and

lipids; begins and completes the digestion of nucleic

acids.

3. Absorbs about 90% of nutrients and water that pass

through the digestive system.


S

MECHANICAL DIGESTION IN THE SMALL INTESTINE

The two types of movements of the small intestine:

Segmentations

• Segmentations mix chyme with the digestive juices and

bring the particles of food into contact with the mucosa

for absorption

Migrating motility complex (MMC)

• begins in the lower portion of the stomach and pushes

chyme forward along a short stretch of small intestine

before dying out




FUNCTIONS OF THE LARGE INTESTINE

1. Haustral churning, peristalsis, and mass peristalsis drive

the contents of the colon into the rectum.

2. Bacteria in the large intestine convert proteins to amino

acids, break down amino acids, and produce some B

vitamins and vitamin K.

3. Absorbing some water, ions, and vitamins.

4. Forming feces.

5. Defecating (emptying the rectum).


THE DEFECATION REFLEX

• Diarrhea is an increase in the frequency, volume, and

fluid content of the feces caused by increased motility of

and decreased absorption by the intestines.

• Constipation refers to infrequent or difficult defecation

caused by decreased motility of the intestines.


PHASES OF DIGESTION

• During the cephalic phase of digestion, the smell, sight,

thought, or initial taste of food activates neural centers in

the cerebral cortex, hypothalamus, and brain stem. The

brain stem then activates the facial (VII),

glossopharyngeal (IX), and vagus (X) nerves. The facial

and glossopharyngeal nerves stimulate the salivary

glands to secrete saliva, while the vagus nerves stimulate

the gastric glands to secrete gastric juice.


• The intestinal phase of digestion begins once food

enters the small intestine.

• The intestinal phase of digestion begins once food

enters the small intestine. Those occurring during the

intestinal phase have inhibitory effects that slow the exit of

chyme from the stomach.



Health History and Clinical Manifestations

SUBJECTIVE DATA

1. GENERAL DATA

a. presence of dental prosthesis, comfort of usage

b. difficulty eating or digesting food

c. nausea or vomiting

d. weight loss

e. pain



SUBJECTIVE DATA

2. SPECIFIC DATA

a. situations or events that effect symptoms

b. onset, possible cause, location, duration, character

of symptoms

c. relationship of specific foods, smoking or alcohol to

severity of symptoms

d. how the symptoms was managed before seeking

medical help


SUBJECTIVE DATA

3. NORMAL PATTERN OF BOWEL ELIMINATION

a. frequency and character of stool

b. use of laxatives, enemas

4. RECENT CHANGES IN NORMAL PATTERNS

a. changes in character of stool (constipation, diarrhea,

or alternating constipation and diarrhea)


SUBJECTIVE DATA

b. changes in color of stool

melena

hematochezia

c. drugs /medications being taken

d. measures taken to relieve symptoms


INDIGESTION

• Indigestion can result from disturbed nervous system

control of the stomach or from a disorder in the GI tract

or elsewhere in the body.

INTESTINAL GAS

• The accumulation of gas in the GI tract may result in

belching or flatulence.


NAUSEA AND VOMITING

• Vomiting is usually preceded by nausea, which can be

triggered by odors, activity, or food intake.

• When vomiting occurs soon after hemorrhage, the

emesis is bright red.

• If blood has been retained in the stomach, it takes on a

coffee-ground appearance because of the action of the

digestive enzymes.


BOWEL HABITS AND STOOL CHARACTERISTIC

• Diarrhea commonly occurs when the contents move so

rapidly through the intestine and colon that there is

inadequate time for the GI secretions to be absorbed.

• Constipation may be associated with anal discomfort

and rectal bleeding.

• Blood in the stool can present in various ways and must

be investigated.


•Blood entering the lower portion of the GI tract or passing

rapidly through it will appear bright or dark red.

• Lower rectal or anal bleeding is suspected if there is

streaking of blood on the surface of the stool.

Other common abnormalities in stool characteristics include

the following:

• Bulky, greasy, foamy stools that are foul in odor; stool color

is gray, with a silvery sheen

• Light gray or clay-colored stool, caused by the absence of

urobilin


• Stool with mucus threads or pus that may be visible on

gross inspection of the stool

• Small, dry, rock-hard masses called scybala; sometimes

streaked with blood from rectal trauma as they pass

through the rectum

• Loose, watery stool that may or may not be streaked with

blood

Physical Assessment

• The patient lies supine with knees flexed slightly for

inspection, auscultation, palpation, and percussion of

the abdomen.

• The nurse performs inspection first, noting skin changes

and scars from previous surgery. It also is important to

note the contour and symmetry of the abdomen, to

identify any localized bulging, distention, or peristaltic

waves.

Physical Assessment

Inspecting the abdomen Auscultating the abdomen

Physical Assessment

• The nurse assesses bowel sounds in all four quadrants

using the diaphragm of the stethoscope; the high-pitched

and gurgling sounds can be heard best in this manner.

• It is important to document the frequency of the sounds,

using the terms normal (sounds heard about every 5 to

20 seconds), hypoactive (one or two sounds in 2

minutes), hyperactive (5 to 6 sounds heard in less than

30 seconds), or absent (no sounds in 3 to 5 minutes).

Physical Assessment

• The nurse notes tympani or dullness during percussion.

Use of light palpation is appropriate for identifying areas

of tenderness or swelling; the nurse may use deep

palpation to identify masses in any of the four quadrants.

• The final part of the examination is inspection of the anal

and perineal area. The nurse should inspect and palpate

areas of excoriation or rash, fissures or fistula openings,

or external hemorrhoids.

Physical Assessment

Palpating the abdomen Percussing the abdomen

Diagnostic Evaluation

Common blood tests include complete blood count (CBC),

carcinoembryonic antigen (CEA), liver function tests, serum

cholesterol, and triglycerides.

General nursing interventions for the patient who is having

GI diagnostic assessment include the following:

• Providing general information about a healthy diet and

the nutritional factors that can cause GI disturbances;

after a diagnosis has been confirmed, the nurse provides

information about specific nutrients that should be

included in the diet.

Diagnostic Evaluation

• Providing needed information about the test and the

activities required of the patient

• Providing instructions about post procedure care and

activity restrictions

• Alleviating anxiety

• Helping the patient cope with discomfort

• Encouraging family members or others to offer emotional

support to the patient during the diagnostic testing

• Assessing for adequate hydration before, during, and

immediately after the procedure

Stool Test

Basic examination of the stool includes:

• inspecting the specimen for consistency and color and

testing for occult blood

• tests for fecal urobilinogen, fat, nitrogen,

• parasites, pathogens, food residues, and other

substances

Stool Test

• The most widely used occult blood test is the Hematest.

False-positive results may occur if the patient has eaten

rare meat, liver, poultry, turnips, broccoli, cauliflower,

melons, salmon, sardines, or horseradish within 7 days

before testing.

•Medications that can cause gastric irritation, such as

aspirin, ibuprofen, indomethacin, colchicine,

corticosteroids, cancer chemotherapeutic agents, and

anticoagulants, may also cause false-positive results.

Breath Test

• The hydrogen breath test was developed to evaluate

carbohydrate absorption. It also is used to aid in the

diagnosis of bacterial overgrowth in the intestine and short

bowel syndrome.

• Urea breath tests detect the presence of Helicobacter

pylori. The patient takes a capsule of carbon labeled urea

and then provides a breath sample 10 to 20 minutes later.

The patient is instructed to avoid antibiotics or loperamide

for 1 month before the test; sucralfate and omeprazole for 1

week before the test; and cimetidine, famotidine, ranitidine,

and nizatidine for 24 hours before urea breath testing.

Abdominal Ultrasonography

• During abdominal ultrasonography, an image of the

abdominal organs and structures is produced on the

oscilloscope. This procedure is generally used to indicate

the size and configuration of abdominal structures.

• Endoscopic ultrasonography (EUS) is a specialized

enteroscopic procedure that aids in the diagnosis of GI

disorders by providing direct imaging of a target area. A

small high-frequency ultrasonic transducer is mounted at

the tip of the fiberoptic scope so that a transintestinal

study can be completed.

Nursing Interventions

• The patient fasts for 8 to 12 hours before the test to

decrease the amount of gas in the bowel.

• If gallbladder studies are being performed, the patient

should eat a fat-free meal the evening before the test.

• If barium studies are to be performed, the nurse should

make sure they are scheduled after this test; otherwise,

the barium will interfere with the transmission of the sound

waves.

DNA Testing

• DNA testing allows practitioners to prevent (or minimize)

disease, by intervening before its onset, and to improve

therapy.

• Persons at risk for colon cancer often are targeted for

DNA testing because it can provide a head start on this

preventable cancer.

Imaging Studies

Imaging studies include:

• x-ray and contrast studies

• computed tomography (CT) scans

• magnetic resonance imaging (MRI)

• and scintigraphy (radionuclide imaging)

Upper GI Tract Study

• X-rays can delineate the entire GI tract after the

introduction of a contrast agent.

• Variations of the upper GI study include double-contrast

studies and enteroclysis.

• The double-contrast method of examining the upper GI

tract involves administration of a thick barium suspension

to outline the stomach and esophageal wall, after which

tablets that release carbon dioxide in the presence of

water are given.


BEFORE THE PROCEDURE:

• maintain a low-residue diet several days before the test

• receive nothing by mouth after midnight before the test

• physician may prescribe a laxative to clean out the

intestinal tract

• discourage the patient from smoking on the morning

before the examination

• withhold all medications as ordered by the physician


AFTER THE PROCEDURE:

• Follow-up care is needed after any of the upper GI

procedures to ensure that the patient has completely

eliminated the ingested barium.

• Fluids must be increased to facilitate evacuation of

stool and barium.

• The nurse monitors the patient’s stools until they return

to their normal color.

• A laxative or enema may be needed as ordered by th

physician.

Lower GI Tract Study

• When barium is instilled rectally to visualize the lower

GI tract, the procedure is called a barium enema.

• The purpose of a barium enema is to detect the

presence of polyps, tumors, and other lesions of the

large intestine and to demonstrate any abnormal

anatomy or malfunction of the bowel.

• The procedure usually takes about 15 to 30 minutes,

during which time x-ray images are taken.


BEFORE THE PROCEDURE:

• a low-residue diet 1 to 2 days before the test

• a clear liquid diet and a laxative the evening before

• nothing by mouth after midnight

• cleansing enemas until returns are clear the following

morning

The nurse should make sure that barium

enemas are scheduled before any upper

GI studies.


CONTRAINDICATIONS FOR BARIUM ENEMA

• patient has active inflammatory disease of the colon

• patients with signs of perforation or obstruction

• active GI bleeding may prohibit the use of laxatives and

enemas

In patients with perforation or obstruction;

a water-soluble contrast study may be

performed in these situations.


CONTRAINDICATIONS FOR BARIUM ENEMA

• patient has active inflammatory disease of the colon

• patients with signs of perforation or obstruction

• active GI bleeding may prohibit the use of laxatives and

enemas

In patients with perforation or obstruction;

a water-soluble contrast study may be

performed in these situations.



• The nurse administers an enema or laxative after these

tests to facilitate barium removal.

• Increasing fluid intake also will assist in eliminating the

barium.

• As with any barium study, the nurse monitors the

patient for complete elimination of the barium.

Computed Tomography

• CT provides cross-sectional images of abdominal

organs and structures.

• Multiple x-ray images are taken from many different

angles, digitized in the computer, reconstructed, and

then viewed on a computer monitor.

• Indications for abdominal CT scanning are diseases of

the liver, spleen, kidney, pancreas, and pelvic organs.

• CT is a valuable tool for detecting and localizing many

inflammatory conditions in the colon, such as

appendicitis, diverticulitis, regional enteritis, and

ulcerative colitis.


• The patient should not eat or drink for 6 to 8 hours

before the test.

• The practitioner may prescribe an intravenous or oral

contrast agent. Therefore, the nurse should question

the patient about contrast dye allergies.

• If barium studies are to be performed, it is important to

schedule them after CT scanning, so as not to interfere

with imaging.

Magnetic Resonance Imaging

• MRI is used in gastroenterology to supplement

ultrasonography and CT scanning.

• It is a noninvasive technique that uses magnetic fields

and radio waves to produce an image of the area being

studied.

• It is useful in evaluating abdominal soft tissues as well

as blood vessels, abscesses, fistulas, neoplasms, and

other sources of bleeding.

Magnetic Resonance Imaging

CONTRAINDICATION FOR MRI

• patients with permanent pacemakers, artificial heart

valves and defibrillators, implanted insulin pumps, or

implanted transcutaneous electrical nerve stimulation

devices

• patients with internal metal devices (e.g., aneurysm

clips) or intraocular metallic fragments



before the test.

• Patient must remove all jewelry and other metals.

• It is important to warn patients that the close-fitting

scanners used in many MRI facilities may induce

feelings of claustrophobia and that the machine will

make a knocking sound during the procedure.

• Open MRIs that are less close-fitting eliminate the

claustrophobia that many patients experience.

Scintigraphy

• Scintigraphy relies on the use of radioactive isotopes

(i.e., technetium, iodine, and indium) to reveal

displaced anatomic structures, changes in organ size,

and the presence of neoplasms or other focal lesions,

such as cysts or abscesses.

• Scintigraphic scanning is also used to measure the

uptake of tagged red blood cells and leukocytes.

• A sample of blood is removed, mixed with a radioactive

substance, and reinjected into the patient.

• Abnormal concentrations of blood cells are then

detected at 24- and 48-hour intervals.

Gastrointestinal Motility Studies

• Radionuclide testing also is used to assess gastric

emptying and colonic transit time.

• For gastric emptying studies, the liquid and solid

components of a meal are tagged with radionuclide

markers.

• After the patient ingests the meal, the patient is

positioned under a scintiscanner, which measures the

rate of passage of the radioactive substance out of the

stomach.

• Abdominal x-rays are taken every 24 hours until all

markers are passed. This process usually takes 4 to 5

days.

Endoscopic Procedures

Endoscopic procedures in GI tract assessment include:

• fibroscopy / esophagogastroduodenoscopy

• anoscopy

• proctoscopy

• sigmoidoscopy

• colonoscopy

• small-bowel enteroscopy

• endoscopy through ostomy


UPPER GI FIBROSCOPY/

ESOPHAGOGASTRODUODENOSCOPY

• Fibroscopy of the upper GI tract allows direct

visualization of the esophageal, gastric, and duodenal

mucosa through a lighted endoscope (gastroscope).

• Esophagogastroduodenoscopy (EGD), is valuable

when esophageal, gastric, or duodenal abnormalities or

inflammatory, neoplastic, or infectious processes are

suspected.

• This procedure also can be used to evaluate

esophageal and gastric motility and to collect

secretions and tissue specimens for further analysis.



BEFORE THE PROCEDURE


before the examination.

• Help the patient spray or gargle with a local anesthetic,

and administer midazolam (Versed) intravenously just

before the scope is introduced.

• The nurse also may administer atropine to reduce

secretions, and may give glucagon, if needed and

prescribed, to relax smooth muscle.

• The nurse positions the patient on the left side to

facilitate saliva drainage and to provide easy access for

the endoscope.


AFTER THE PROCEDURE

• After the procedure, the nurse instructs the patient not

to eat or drink until the gag reflex returns (in 1 to 2

hours), to prevent aspiration of food or fluids into the

lungs.

• The nurse places the patient in the Simms position until

he or she is awake and then places the patient in the

semi-Fowler’s position until ready for discharge.

• After gastroscopy, assessment by the nurse includes

observing for signs of perforation, such as pain,

bleeding, unusual difficulty swallowing, and an elevated

temperature.


AFTER THE PROCEDURE

• The nurse monitors the pulse and blood pressure for

changes that can occur with sedation.

• After the patient’s gag reflex has returned, the nurse

can offer lozenges, saline gargle, and oral analgesics

to relieve minor throat discomfort.

• Patients who were sedated for the procedure must stay

on bed rest until fully alert.


ANOSCOPY, PROCTOSCOPY, AND SIGMOIDOSCOPY

• The lower portion of the colon also can be viewed

directly to evaluate rectal bleeding, acute or chronic

diarrhea, or change in bowel patterns and to observe

for ulceration, fissures, abscesses, tumors, polyps, or

other pathologic processes.

• The anoscope is a rigid scope that is used to examine

the anus and lower rectum.

• Proctoscopes and sigmoidoscopes are rigid scopes

that are used to inspect the rectum and the sigmoid

colon.


• For rigid scope procedures, the patient assumes the

knee-chest position at the edge of the bed or the

examining table. With the back inclined at about a 45-

degree angle, the patient is properly positioned for the

introduction of an anoscope, proctoscope, or

sigmoidoscope.

• For flexible scope procedures, the patient assumes a

comfortable position on the left side with the right leg

bent and placed anteriorly.

• Biopsy is performed with small biting forceps

introduced through the endoscope; one or more small

pieces of tissue may be removed.


Nursing Intercentions

• These examinations require only limited bowel

preparation, including a warm tap water or Fleet’s

enema until returns are clear.

• During the procedure, the nurse monitors vital signs,

skin color and temperature, pain tolerance, and vagal

response.

• After the procedure, the nurse monitors the patient for

rectal bleeding and signs of intestinal perforation (ie,

fever, rectal drainage, abdominal distention, and pain).


FIBEROPTIC COLONOSCOPY

• Fiberoptic colonoscope are larger in diameter and

longer.

• It is most frequently used for cancer screening and for

surveillance in patients with previous colon cancer or

polyps.

• Tissue biopsies can be obtained as needed, and polyps

can be removed and evaluated.

• Therapeutically, the procedure can be used to remove

all visible polyps, areas of bleeding or stricture.


• Colonoscopy is performed while the patient is lying on

the left side with the legs drawn up toward the chest.

• The procedure usually takes about 1 hour. Discomfort

may result from instillation of air to expand the colon or

from insertion and moving of the scope.

• Potential complications of colonoscopy include cardiac

dysrhythmias and respiratory depression resulting from

the medications administered, vasovagal reactions,

and circulatory overload or hypotension resulting from

overhydration or underhydration during bowel

preparation.


• Colonoscopy is performed while the patient is lying on

the left side with the legs drawn up toward the chest.

• The procedure usually takes about 1 hour. Discomfort

may result from instillation of air to expand the colon or

from insertion and moving of the scope.

• Potential complications of colonoscopy include cardiac

dysrhythmias and respiratory depression resulting from

the medications administered, vasovagal reactions,

and circulatory overload or hypotension resulting from

overhydration or underhydration during bowel

preparation.



BEFORE THE PROCEDURE

• Patient should limit the intake of liquids for 24 to 72

hours before the examination.

• The physician may prescribe a laxative for two nights

before the examination and a Fleet’s or saline enema

until the return runs clear the morning of the test.

• Polyethylene glycol electrolyte lavage solutions

(Golytely, Colyte, NuLytely) are used as intestinal

lavages for effective cleansing of the bowel.

• The patient maintains a clear liquid diet starting at noon

the day before the procedure. Then the patient ingests

lavage solutions orally at intervals over 3 to 4 hours.


• Instructing the patient not to take routine medications

when the lavage solution is ingested; the medications

will not be digested and therefore will be ineffective

• Advising the diabetic patient to consult with his or her

physician about medication adjustment to prevent

hyperglycemia or hypoglycemia resulting from dietary

modifications required in preparation for the test

• Instructing all patients, especially the elderly, to

maintain adequate fluid, electrolyte, and caloric intake

while undergoing bowel cleansing


DURING THE PROCEDURE:

• Informed consent is obtained before the test.

• Before the examination, the nurse may administer

intravenously an opioid analgesic or a sedative (eg,

midazolam) to provide moderate sedation and relieve

anxiety during the procedure.

• Glucagon may be used, if needed, to relax the colonic

musculature and to reduce spasm during the test.

• Elderly or debilitated patients may require a reduced

dosage of these medications to decrease the risks of

oversedation and cardiopulmonary complications.


• The nurse monitors for changes in oxygen saturation,

vital signs, color and temperature of the skin, level of

consciousness, abdominal distention, vagal response,

and pain intensity.



• Patients who were sedated are maintained on bed rest

until fully alert.

• Some will have abdominal cramps caused by

increased peristalsis stimulated by the air insufflated

into the bowel during the procedure.

• The nurse observes the patient for signs and

symptoms of bowel perforation (eg, rectal bleeding,

abdominal pain or distention, fever, focal peritoneal

signs).

• If midazolam was used, the nurse explains its amnesic

effects.


• It is important to provide written instructions, because

the patient may be unable to recall verbal information.

• If the procedure is performed on an outpatient basis,

someone must accompany and transport the patient

home.

• After a therapeutic procedure, the nurse instructs the

patient to report any bleeding to the physician.


Side effects of the electrolyte solutions include:

• nausea

• bloating

• cramps or abdominal fullness

• fluid and electrolyte imbalance

• hypothermia (patients are often told to drink the

preparation as cold as possible to make it more

palatable)

Nursing Intercentions

CONTRAINDICATIONS:

• Patients with intestinal obstruction or inflammatory

bowel disease.

• Implantable defibrillators and pacemakers are at high

risk for malfunction if electrosurgical procedures (ie,

polypectomy) are performed in conjunction with

colonoscopy.

• Colonoscopy cannot be performed if there is a

suspected or documented colon perforation, acute

severe diverticulitis, or fulminant colitis.


• Therapeutic colonoscopy may be contraindicated in

patients with coagulopathies and in those receiving

anticoagulation therapy, because of the high risk for

excessive bleeding during and after the procedure.

• Nonsteroidal anti-inflammatory agents (NSAIDs),

aspirin, ticlopidine, and pentoxifylline must be

discontinued before the test and for 2 weeks after the

procedure. Patients taking coumadin or heparin must

consult the physician for specific instructions.

• Those with prosthetic heart valves or a history of

endocarditis require prophylactic antibiotics before the

procedure.


ENDOSCOPY THROUGH OSTOMY

• Endoscopy using a flexible endoscope through an

ostomy stoma is useful for visualizing a segment of the

small or large intestine.

• It may be indicated to evaluate an anastomosis, to

screen for recurrent disease, or to visualize and treat

bleeding in a segment of the bowel.

Manometry and Electrophysiologic Studies

• The manometry test measures changes in intraluminal

pressures and the coordination of muscle activity in the

GI tract. The pressures can be recorded manually, on a

physiograph, or on a computer.

• Electrogastrography, an electrophysiologic study, is

performed to assess gastric motility disturbances.

Electrodes are placed over the abdomen, and gastric

electrical activity is recorded for up to 24 hours.

Electrogastrography can be useful in detecting motor or

nerve dysfunction in the stomach.

Defecography

• Defecography measures anorectal function. Very thick

barium paste is instilled into the rectum, and then

fluoroscopy is performed to assess the function of the

rectum and anal sphincter while the patient attempts to

expel the barium.

• Electromyographic (EMG) studies can supplement

anorectal manometry to measure the integrity and

function of the anal sphincters in an effort to treat

functional bowel incontinence and constipation.

Gastric Analysis

• Analysis of the gastric juice yields information about the

secretory activity of the gastric mucosa and the

presence or degree of gastric retention in patients

thought to have pyloric or duodenal obstruction.

• Important diagnostic information to be gained from

gastric analysis includes the ability of the mucosa to

secrete HCl.


• The patient is kept NPO for 8 to 12 hours before the

procedure.

• Any medications that affect gastric secretions are

withheld for 24 to 48 hours before the test.

• Smoking is not allowed on the morning before the test,

because it increases gastric secretions.

Gastric Stimulation Test

• The gastric acid stimulation test usually is performed in

conjunction with gastric analysis.

• Histamine is administered subcutaneously to stimulate

gastric secretions. It is important to inform the patient

that this injection may produce a flushed feeling.

• Gastric specimens are collected after the injection

every 15 minutes for 1 hour and are labeled to indicate

the time of specimen collection after histamine

injection.

• The volume and pH of the specimen are measured.


• Inform the patient that this injection may produce a

flushed feeling.

• The nurse monitors blood pressure and pulse

frequently to detect hypotension.

Laparoscopy

• This procedure is performed through a small incision in

the abdominal wall. Special fiberoptic laparoscopes

allow direct visualization of the organs and structures

within the abdomen, permitting visualization and

identification of any growths, anomalies, and

inflammatory processes.

• Biopsy samples can be taken from the structures and

organs as necessary.

• This procedure can be used to evaluate peritoneal

disease, chronic abdominal pain, abdominal masses,

and gallbladder and liver disease.

Assignment!

1. As a student nurse assigned at the emergency room,

you are in charge of a 24-year-old male patient who

was admitted for acute abdominal pain. He is being

scheduled for tests this afternoon. What laboratory

tests would you expect to be ordered? What

preparation is needed for these tests? What

preprocedure education is needed?

Assignment!

2. A 58-year-old patient assigned to you this morning has

just left to go to the Endoscopy Suite, where she will

undergo a colonoscopy. You know that your patient will

receive moderate sedation during the procedure and that

she will be returned to your care once she is fully alert.

What should you anticipate in the course of recovery for

your patient after the colonoscopy? What medications

might be used for the moderate sedation, and what

effects of those medications would you expect to see

during the recovery period? Describe the potential

complications that could occur and what you will monitor.

What are the goals for care during this period?

Health & Medicine

GI System 1 Lecture