- Medical–Surgical Nursing: Gastrointestinal System
- FURTHER READING/STUDY:
- NCLEX-RN: Test-Taking Strategies
- NCLEX: End-of-life care
- NCLEX: MUSCULOSKELETAL DISORDERS
- NCLEX: Gerontologic care
- NCLEX: Obesity
- NCLEX: Cancer care
Medical–Surgical Nursing: Gastrointestinal System
Focus topic: Medical–Surgical Nursing
The alimentary tract’s primary function is to provide the body with a continual supply of nutrients, fluids, and electrolytes for tissue nourishment. This system has three components: a tract for ingestion and movement of food and fluids; secretion of digestive juices for breaking down the nutrients; and absorption mechanisms for the utilization of foods, water, and electrolytes for continued growth and repair of body tissues.
Medical–Surgical Nursing: Anatomy and Physiology
Focus topic: Medical–Surgical Nursing
Medical–Surgical Nursing: Main Organs
Focus topic: Medical–Surgical Nursing
Description: The main organs of the gastrointestinal (GI) system include the mouth, pharynx, esophagus, stomach, small intestine, and large intestine.
A. Normally, the GI system is the only source of intake for the body.
B. Provides the body with fluids, nutrients, and electrolytes.
C. Provides means of disposal for waste residues.
A. Secretion of enzymes and electrolytes are used to break down the raw materials ingested.
B. Movement of ingested products through the system.
C. Complete digestion of ingested nutrients.
D. Absorption of the end products of digestion into the blood.
Coats of Tissue Walls
A. Mucous lining.
- Rugae and microscopic gastric and hydrochloric acid glands in the stomach.
- Villi, intestinal gland Peyer’s patches, and lymph nodes.
- Intestinal glands.
B. Submucous coat of connective tissue, in which the main blood vessels are located.
C. Muscular coat.
- Digestive organs have circular and longitudinal muscle fibers.
- The stomach has oblique fibers in addition to circular and longitudinal fibers.
D. Fibroserous coat, the outer coat.
- In the stomach, the omentum hangs from the lower edge of the stomach, over the intestines.
- In the intestines, it forms the visceral peritoneum.
The Mouth, Pharynx, and Esophagus
A. The buccal cavity.
- Hard and soft palates.
- Maxillary bones.
B. The pharynx.
- ubelike structure that extends from the base of the skull to the esophagus.
- Compound of muscle lined with mucous membrane, composed of the nasopharynx, the oropharynx, and the laryngopharynx.
- Functions include serving as a pathway for the respiratory and digestive tracts, and playing an important role in phonation.
C. The esophagus begins at the lower end of the pharynx and is a collapsible muscular tube about 10 inches (25 cm) long.
- It leads to the abdominal portion of the digestive tract.
- The main portion is lined with many simple mucous glands; complex mucous glands are located at the esophagogastric juncture.
A. Elongated pouch lying in the epigastric and left hypochondriac portions of the abdominal cavity (approximately 10 inches [25 cm]).
B. Divisions are the fundus, the body, and the pylorus (the constricted lower portion).
C. Curvatures are the lesser curvature and the greater curvature.
D . Sphincters.
- Cardiac sphincter—at the opening of the esophagus into the stomach.
- Pyloric sphincter—guards the opening of the pylorus into the duodenum.
- The mucous coat allows for distention and contains microscopic glands: gastric, hydrochloric acid, and mucous.
- The muscle coat contains three layers.
a. Circular—forms the two sphincters.
- The fibroserous coat forms the visceral peritoneum; the omentum hangs in a double fold over the intestines.
- Mucous glands—secrete mucus to provide protection from gastric juice.
- Goblet cells—secrete viscid mucus.
- Gastric glands.
a. Parietal—secrete hydrochloric acid and intrinsic factor.
b. Chief cells—secrete pepsin, lipase, amylase, and renin.
H. Function: mechanical and chemical digestion.
a. A storage reservoir for food.
b. Churning provides for forward and backward movement.
c. Peristalsis moves material through the stomach and, at intervals with relaxation of the pyloric sphincter, squirts chyme into the duodenum.
a. Hydrochloric acid provides the proper medium for action of pepsin and aids in the coagulation of milk in adults.
b. Pepsin splits protein into proteoses and peptones.
c. Lipase is a fat-splitting enzyme with limited action.
d. Renin coagulates or curdles the protein of milk.
e. Intrinsic factor acts on certain components of food to form the antianemic factor.
f. Mixes food with gastric juices into a thick fluid called chyme.
The Small Intestine
A. Approximately 21 feet (6 m).
- The duodenum (about 10 inches [25 cm]) includes the Brunner’s glands (the duodenal mucous digestive glands) and the openings for the bile and pancreatic ducts.
- The jejunum is approximately 8 feet (2.4 m) long; the ileum is approximately 12 feet (3.6 m) long. Both have deep circular folds that increase their absorptive surfaces.
a. The mucous lining has numerous villi, each of which has an arteriole, venule and lymph vessel that serve as structures for the absorption of digested food.
b. The small intestine terminates by opening into the cecum (the opening is guarded by the ileocecal valve).
C. Intestinal digestion.
- Intestinal juice has an alkaline reaction and contains a large number of enzymes.
The Large Intestine (Colon)
A. Approximately 5 feet (1.5 m) long, with a relatively smooth mucous membrane surface. The only secretion is mucus.
B. Muscle coats pucker the wall of the colon into a series of pouches (haustra) and contain the internal and the external anal sphincters.
- The cecum (the first part of the large intestine) is guarded by the ileocecal valve.
a. Prevents regurgitation of the cecal contents into the ileum.
b. 3 L of fluid passes through the small bowel but only 500 mL passes through the ileocecal valve.
- The appendix is attached to its surface as an extension. The appendix is a twisted structure that may accumulate bacteria and become inflamed.
f. Anus—a hairless, darker-skinned area at the end of the digestive tract. It has an internal involuntary sphincter and an external voluntary sphincter.
- Absorption and elimination of wastes.
- Formation of vitamins: K, B12, riboflavin, and thiamine.
- Mechanical digestion: churning, peristalsis, and defecation.
- Absorption of water from fecal mass.
Medical–Surgical Nursing: Accessory Organs
Focus topic: Medical–Surgical Nursing
Description: The accessory organs of the gastrointestinal system include the teeth, tongue, salivary glands, pancreas, liver, gallbladder, and appendix.
A. A skeletal muscle covered with a mucous membrane that aids in chewing, swallowing, and speaking.
B. Papillae on the surface of the tongue contain taste buds.
C. The frenulum is a fold of mucous membrane that helps to anchor the tongue to the floor of the mouth.
D. The tongue mixes food with saliva to form a mass called a bolus.
A. Three pairs—the submaxillary, the sublingual, and
the parotid glands.
1. Saliva is secreted by the glands when sensory
nerve endings are stimulated mechanically,
thermally, or chemically.
2. pH ranges: 6.0–7.9.
3. Contains amylase, an enzyme that hydrolyzes
A. Deciduous teeth (20 in the set) and permanent
teeth (32 in the set).
B. The functions are mastication and mixing saliva
A. Location and size.
- Located in the right hypochondrium and part of the epigastrium.
- It is the largest gland in the body, weighing about 3 pounds (1.3 kg).
- It is protected by the lower ribs and is in contact with the undersurface of the dome of the diaphragm.
B. Lobes—right lobes (include the right lobe proper, the caudate, and the quadrate) and left lobe.
- Lobes are divided into lobules by blood vessels and fibrous partitions.
- The lobule is the basic structure of the liver and contains hepatic cells and capillaries.
C. Ducts include the hepatic duct from the liver, the cystic duct from the gallbladder, and the common bile duct (the union of the hepatic and cystic ducts).
Functions of the Liver
A. Metabolism of carbohydrates.
- Converts glucose to glycogen and stores glycogen.
- Converts glycogen to glucose.
- Glycogenolysis—the supply of carbohydrates released into bloodstream.
B. Metabolism of fats.
- Oxidation of fatty acids and formation of acetoacetic acid.
- Formation of lipoproteins, cholesterol, and phospholipids.
- Conversion of carbohydrates and protein into fat.
C. Metabolism of proteins.
- Deamination of amino acids.
- Formation of urea.
- Formation of plasma proteins.
- Interconversions among amino acid and other compounds.
D. Vascular functions for storage and filtration of blood.
- Blood (200–400 mL) can be stored by the liver.
- Fat-soluble vitamins (A, D, E, and K), B12, copper, and iron are stored in the liver.
- Detoxifies harmful substances in the blood.
- Breaks down worn-out blood cells.
- Filters blood as it comes through the portal system.
- Synthesizes prothrombin, fibrinogen, and factors I, II, VII, IX, and X, which are necessary for blood clotting.
E. Secretory functions.
- Constant secretion (500–1000 mL in 24 hours) of bile, which is stored in the gallbladder.
- Bile is a yellow–brown viscous fluid, alkaline in reaction, and consists of bile salts, bile pigments, cholesterol, and inorganic salts.
- Bile emulsifies fats.
- Red blood cell destruction releases hemoglobin, which changes to bilirubin; bilirubin unites with plasma proteins and is removed by the liver and excreted in the bile.
- The bile pigment bilirubin is converted by bacterial action into urobilin and to urobilinogen (appears in urine and gives feces brown color).
F. Hepatic reticuloendothelial functions.
- Inner surface of the liver sinusoids contains Kupffer cells.
- Kupffer cells are phagocytic and are capable of removing bacteria in the portal venous blood.
G. Sex hormone and aldosterone metabolism.
A. Small sac of smooth muscle located in a depression at the edge of the visceral surface of the liver, which functions as a reservoir for bile.
- Cystic duct—the duct of the gallbladder joins the hepatic duct, which descends from the liver, to form the common bile duct.
- The common bile duct is joined by the duct of the pancreas (Wirsung’s duct) as it enters the duodenum.
- The sphincter of Oddi guards the common entrance.
B. Secretion—the presence of fatty materials in the duodenum stimulates the liberation of cholecystokinin, which causes contraction of the gallbladder and relaxation of the sphincter of Oddi.
A. A soft, pink-white organ, 15 cm long and 2.5 cm wide (5.9 in long and .98 wide), which adheres to the middle portion of the duodenum.
B. Divided into lobes and lobules.
- Exocrine portion secretes digestive enzymes, which are carried to the duodenum by Wirsung’s duct.
- Endocrine secretion is produced by the islets of Langerhans; insulin is secreted into the bloodstream and plays an important role in carbohydrate metabolism.
C. Pancreatic juices contain enzymes for digesting proteins, carbohydrates, and fats.
- Enzymes are secreted as inactive precursors, which do not become active until secreted into the intestine (otherwise they would digest the gland).
a. Converts trypsinogen to trypsin to act on proteins, producing peptones, peptides and amino acids.
b. Pancreatic amylase acts on carbohydrates, producing disaccharides.
c. Pancreatic lipase acts on fats, producing glycerol and fatty acids.
D. Two regulatory mechanisms of pancreatic secretion.
- Nervous regulation—distention of the intestine.
- Hormonal regulation.
a. Chyme in the intestinal mucosa causes the release of secretin (which stimulates the pancreas to secrete large quantities of fluid) and pancreozymin.
b. Pancreozymin passes by way of the blood to the pancreas and causes secretion of large quantities of digestive enzymes.
Medical–Surgical Nursing: System Assessment
Focus topic: Medical–Surgical Nursing
A. Evaluate client’s history regarding reported signs and symptoms.
B. Assess overall condition of client, including vital signs and level of consciousness.
C. Evaluate condition of mouth, teeth, gums, and tongue.
- Foul odor to breath may indicate diseased teeth, gums, or poor assimilation along gastrointestinal tract.
- Coated tongue may indicate chemical imbalance in system.
D. Check for presence of gag reflex.
E. Assess general contour of abdomen with client lying flat.
F. Assess for bowel sounds: hyperactive or hypoactive.
- Hypoactive bowel sounds may be due to peritonitis, paralytic ileus, or no obvious cause.
- Absent bowel sounds may be due to bowel obstruction or systemic illness.
G. Check bowel habits and/or alterations in bowel elimination.
H. Palpate abdominal muscles for tenderness or rigidity; evaluate all quadrants of abdomen.
I. Assess bowel motility.
- Hypermotility may be result of irritation of autonomic nervous system or inflammatory process.
- Hypomotility may be result of blockage, intestinal muscle weakness, or chemical agents.
J. Check for amount of flatulence client reports, which indicates malfunction of system or dietary indiscretion.
K. Assess stool specimen.
- Check for presence of blood.
- Check for presence of mucus.
- Evaluate consistency, color, and odor of stool.
L. Assess for parasites.
M. Assess fluid intake per day.
N. Evaluate dietary program (e.g., type of foods, amount).
O. Evaluate laboratory tests.
P. Note presence or absence of hemorrhoids.
Q. Assess the degree of sphincter control by the client’s reports of his or her ability to control and regulate bowel movements.
R. Assess for presence of pain along gastrointestinal tract and in accessory organs.
- Assess nonverbal signs, such as flinching, grimacing, etc.
- Evaluate onset, location, intensity, duration, and aggravating factors.
S. Palpate for rebound tenderness of spleen.
T. Check skin color for yellow tinge, pallor, or heavy flushing.
U. Assess for signs of shock following trauma to abdomen.
V. Assess client’s knowledge of diagnostic tests or surgical interventions.
W. Assess sclerae for jaundice.
Medical–Surgical Nursing: Diagnostic Procedures
Focus topic: Medical–Surgical Nursing
Roentgenography of the Gastrointestinal Tract
A. The gastrointestinal tract cannot be visualized unless a contrast medium is ingested or instilled into it.
B. Barium sulfate—a white, chalky radiopaque substance that can be flavored—is normally used as
a contrast medium.
C. For an upper GI tract study, the client ingests an aqueous suspension of barium. The progression of barium is followed by the fluoroscope.
D. Roentgenography of the upper tract reveals
- Structure and function of the esophagus.
- Size and shape of the right atrium.
- Esophageal varices.
- Thickness of gastric wall.
- Motility of the stomach.
- Ulcerations, tumor formations, and anatomic abnormalities of the stomach.
- Pyloric valve patency.
- Emptying time of the stomach.
- Structural abnormalities of the small intestine.
E. X-rays are taken for permanent records.
F. Preparation of client for an upper GI roentgenograph.
- Maintain NPO after midnight, prior to the test.
- Withhold medication.
- Explain procedure.
G. The lower GI roentgenograph involves rectal instillation of barium, which is viewed with the fluoroscope. Then, permanent x-rays are taken.
H. The lower GI roentgenograph reveals the following information:
- Abnormalities in the structure of the colon.
- Contour and motility of the cecum and appendix.
I. Preparation of client for a lower GI roentgenograph.
- Empty intestinal tract by giving an enema, laxatives, or suppositories as ordered.
- Maintain NPO after midnight, prior to the examination.
- Explain procedure to client.
- Increase fluid intake and administer laxative, if needed, following procedure.
A. Visualization of the inside of a body cavity by means of a lighted tube.
B. Flexible scopes are used for these examinations; scopes may be equipped with a camera.
- Direct visualization of mucosa to detect pathologic lesions.
- Obtaining biopsy specimens.
- Securing washings for cytologic examination.
D. Organs capable of being scoped: esophagus, stomach, duodenum, rectum, sigmoid colon, transverse colon, and right colon.
E. Nursing implementation.
- Explain procedure to client.
- Ensure that a signed consent for the procedure is present in the chart. Endoscopy is an invasive procedure and requires an informed consent.
- Have client fast prior to the examination.
- Prepare the lower bowel with laxatives, enemas, or suppositories as ordered.
- Remove dentures and check for loose teeth prior to the procedure.
- Prior to gastroscopy, conscious sedation and a local anesthetic may be used in the posterior pharynx. Withhold fluids and food after the procedure until the gag reflex has returned.
- Support client during the procedure. The muscles of the GI tract tend to go into spasm with the passage of the scope, causing pain.
- Following the endoscopy.
a. Observe for hemorrhage, swelling, or dysfunction of the involved area.
b. Monitor vital signs.
c. Evaluate client for evidence of complications (bleeding, dyspnea, fever, abdominal pain).
d. For upper GI, withhold all food and fluids until gag and swallow reflexes have returned.
e. Inform client that a sore throat, hoarseness, abdominal bloating, belching, and flatulence are common.
f. Ensure that client is not discharged alone until sedation is completely worn off.
g. Instruct client to inform physician immediately if the following occur: persistent difficulty swallowing; epigastric, substernal, or shoulder pain; vomiting blood; black, tarry stools; or fever.
Analysis of Secretions
A. Contents of the GI tract may be examined for the presence or absence of digestive juices, bacteria, parasites, and malignant cells.
B. Stomach contents may be aspirated and analyzed for volume and free and total acid.
C. Gastric analysis, performed by means of a nasogastric tube.
- Maintain NPO 6–8 hours prior to the test.
- Pass nasogastric tube, verify its presence in the stomach, tape to client’s nose.
- Collect fasting specimens.
- Administer agents, such as alcohol, caffeine, histamine (0.2 mg subcutaneous), as ordered, to stimulate the flow of gastric acid.
a. Watch for side effects of histamine, including flushing, headache, and hypotension.
b. Do not give drug to clients with a history of asthma or other allergic conditions.
- Collect specimens as ordered, usually at 10- to 20-minute intervals.
- Label specimens and send to laboratory.
- Withdraw nasogastric tube, offer oral hygiene, make client comfortable.
- Gastric acid is high in the presence of duodenal ulcers and low in pernicious anemia.
D . Gastric washings for acid-fast bacilli.
- Have client fast 6–8 hours prior to the procedure.
- Insert nasogastric tube and secure to client’s nose.
- Send specimens to the laboratory to determine the presence of acid-fast bacilli.
- Wash your hands carefully, wear gloves, and protect yourself from direct contact with specimens.
- This procedure is performed on suspected cases of active pulmonary tuberculosis when it is difficult to secure sputum for analysis and clients have swallowed sputum.
E. Analysis of stools.
- Stool specimens are examined for amount, consistency, color, shape, blood, fecal urobilinogen, fat, nitrogen, parasites, food residue, and other substances.
- Stool cultures are also done for bacteria and viruses.
- Some foods and medicines can affect stool color: spinach, green; cocoa, dark red; senna, yellow; iron, black; upper GI bleeding, tarry black; lower GI bleeding, bright red.
- Stool abnormalities.
a. Steatorrhea: bulky, greasy and foamy, foul odor.
b. Biliary obstruction: light gray or clay-colored.
c. Ulcerative colitis: loose stools, with copious amounts of mucus or pus.
d. Constipation or obstruction: small, hard masses.
- Specimen collection.
a. Specimens for detection of ova and parasites should be sent to the laboratory while the stool is still warm and fresh.
b. Examination for guaiac (occult blood) is performed on a small sample that is sent to the lab, or, a sample is placed on a commercially prepared card. A positive result indicates blood in the stool.
c. Stools for chemical analysis are usually examined for the total quantity expelled, so the complete stool is sent to the laboratory.
Biopsy and Cytology
A. Specimens for microscopic examination are secured by endoscopy examination, cell scrapings, and needle aspiration.
B. Specimens are examined, and the laboratory then determines their origin, structure, and functions, and the presence of malignant cells.
A. Radionuclides are used for diagnosis by measuring the localization of the substance, such as radioiodine in the thyroid, and the excretion of the material.
B. Various substances are studied, such as vitamin B12, iron, and fat, and major organs can be scanned.
C. Substances are tagged with radioactive isotopes to assess the degree of absorption.
A. Hematologic studies and electrolyte determinations reveal information about the general status of the client.
B. Results of these examinations in conjunction with other assessment procedures and clinical symptoms help to localize the disorder.
A. Monitor vital signs.
B. Check for signs of dehydration.
- Dry mucous membranes.
- Poor skin turgor.
- Decreased urination.
- Increased pulse.
C. Monitor fluid intake or intravenous (IV) administration if ordered.
D. Monitor dietary intake or NPO status as ordered.
E. Check and record stool pattern, consistency, color, odor, presence of blood or pus, etc.
F. Evaluate laboratory results of stool culture.
G. Observe skin tone, color, and changes.
H. Administer enema if ordered.
I. Promote bowel regulation through client teaching of dietary information.
J. Perform and teach colostomy or ileostomy care to client.
K. Place or assist physician in placing Miller–Abbott tube for relief of distention if ordered.
L. Instruct client on diagnostic tests.
M. Instruct client in preoperative and postoperative care.