Download Gastrointestinal System

Gastrointestinal System
Minasyan Zoya
RN,MSN-Edu
Location of organs of the
gastrointestinal system
Parts of the stomach
Ingestion and Propulsion of Food
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Mouth
Pharynx
Esophagus
Stomach
Small Intestine
Large intestine
Anatomic locations of the large
intestine
Structure of the liver, gallbladder,
pancreas, and duct system
Microscopic structure of liver lobule
Bilirubin metabolism and conjugation
Assessment of Gastrointestinal System
• Physical examination
• Abdomen
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Inspection
Auscultation
Percussion
Palpation
Diagnostic studies (table 39-12,page 913-916
Lewis,8th edition)
• Radiologic Studies
• Upper gastrointestinal series
• Lower gastrointestinal series
• Virtual colonoscopy
• Endoscopy
• Liver Biopsy
• Liver Function Studies (table 39-13)
A. Barium enema x-ray showing the large intestine
B. Ultrasound of gallbladder showing multiple gallstones
Ileocecal junction
A. Illustration showing the ileocecal junction and the ileocecal fold
B. Endoscopic image of the ileocecal fold
Malnutrition
• Deficit, excess, or imbalance in essential
components of balanced diet
– Undernutrition
• Poor nourishment due to inadequate diet or disease
– Overnutrition
• Ingestion of more food than required
Starvation process
– Initially, body uses carbohydrate stores from liver and
muscle to meet metabolic needs.
– Stores are minimal and may be depleted in 18hrs.
– Once stores are depleted, protein is converted to
glucose for energy.
– Gluconeogenesis occurs (formation of glucose by liver)
– Allows metabolic processes to continue
– Negative nitrogen balance
– In 5 to 9 days, fat is mobilized to supply energy.
– Prolonged starvation: 97% of calories from fat and
protein are conserved
– Fat stores used in 4 to 6 weeks, depends on amount
available
– Once fat stores are used, body proteins (from internal
organs and plasma) are no longer spared.
Starvation process
– Liver function impaired
– Protein synthesis diminished
– Plasma oncotic pressure ↓
• Shift from vascular space into interstitial
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Albumin leaks into interstitial space;edema presents.
Skin is dry and wrinkled.
Na+/K+ pump fails—deficiency in calories and proteins
Liver loses mass, becomes infiltrated with fat.
Diet of protein and other constituents must be
initiated, or death will occur.
Malnutrition
Patient with malnutrition.
Nursing Diagnoses
• Imbalanced nutrition: Less than body
requirements
• Self-care deficit (feeding)
• Constipation or diarrhea
• Deficient fluid volume
• Risk for impaired skin integrity
• Noncompliance
• Activity intolerance
Normal Nutrition
• Essential components of basic food groups
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Carbohydrates
Fats
Proteins
Vitamins
Minerals
Food Pyramid
In the My Pyramid, each food group is characterized by varying widths, representative of the proportion of
each group that should be eaten. The person climbing the stairs on the side of the pyramid indicates the
need to include daily physical activity in a healthy lifestyle.
Special Diets
• Vegetarian
– Common element is exclusion of red meat from diet.
– Well-planned diets needed to avoid deficiencies
– Various reasons for following
• Religious
• CulturalVegans
– Eat only plant foods
– Lack of cobalamin (vitamin B12) common
– Can develop megaloblastic anemia and neurologic symptoms of
deficiency
– Other possible deficiencies
– Calcium, zinc, vitamins A and D, protein, iron
• Lacto-ovo vegetarians
 Eat plant foods and sometimes dairy products and eggs
 Watch for vitamin and mineral deficiencies
• Iron deficiency
Parenteral Nutrition
– Administration of nutrients by route other than GI tract
(i.e., bloodstream)
– Used when
• GI tract cannot be used for ingestion, digestion, and
absorption of essential nutrients.
• Goal: Meet nutritional needs and allow growth of new
body tissue
• Normal adult requires minimum 1200 to 1500 calories/day.
Common Indications for PN
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Chronic or intractable diarrhea and vomiting
Complicated surgery or trauma
Gastrointestinal obstruction
Gastrointestinal tract anomalies and fistulae
Malnutrition
Parenteral Nutrition
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Methods of administration
– Central or peripheral use
– Central parenteral nutrition through catheter whose tip lies in
superior vena cava
• Subclavian or jugular vein
• Peripherally inserted central catheters (PICCs)
 Long-term parenteral support
 Peripheral parenteral nutrition
• Through peripherally inserted catheter or vascular access device
• Short-term support
• Protein and caloric requirements not high
• Risk of central catheter too great
• Supplement inadequate oral intake
Parenteral Nutrition
• Central and peripheral nutrition differ in tonicity
– Central solutions are hypertonic.
• Large central vein can handle high glucose
content ranging from 20% to 50%.
– Peripheral solutions are hypertonic.
• Peripheral vein can handle glucose up to 20%.
• PN solutions are prepared by pharmacist or trained
technician under strict aseptic techniques.
 Nothing is added to solution after it is prepared.
 Solutions are good for 24 hours
Parenteral Nutrition
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Catheter placement under sterile conditions by physician or advanced
practice nurse
– Isotonic IV solution infused until x-ray confirms correct placement
– Site covered with sterile dressing
– Date marked on dressing
Complications of PN
 Infection
• Must have filter
• With lipids: Tubing, filter change every 24 hours
• With amino acids, dextrose: Filter, tubing change every 72 hours
 Fungus, Gram +/- bacteria
 Metabolic problems
 Hyperglycemia, hypoglycemia, prerenal azotemia, fatty acid
deficiency, electrolyte disturbances, hyperlipidemia, mineral
deficiencies
 Mechanical problems
• Insertion problems
• Dislodgement, thrombosis of great vein, phlebitis
Parenteral Nutrition
Nursing Management
• Vital signs every 4 to 8 hours
• Daily weights
• Blood glucose
– Check initially every 4 to 6 hours.
• Electrolytes
• BUN
• CBC
Oral Feeding
• High-calorie supplements
• Used when nutritional intake is deficient
• Examples include
– Milkshakes
– Puddings
– Ensure, Sustacal
• Used as snacks
Enteral Nutrition
• Also known as tube feeding
• Administration of nutritionally balanced liquefied food or
formula through tube inserted into
– Stomach
– Duodenum
– Jejunum
• Provides nutrients to GI tract alone or supplemental to oral
or parenteral nutrition
• Easily administered
• Safer than parenteral
• More physiologically efficient than parenteral
• Less expensive than parenteral
Enteral Nutrition
• Indications include those with
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Anorexia
Orofacial fractures
Head/neck cancer
Burns
Nutritional deficiencies
Neurologic conditions
Psychiatric conditions
Chemotherapy
Radiation therapy
• Delivery options include
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Continuous infusion by pump
Intermittent by gravity
Intermittent bolus by syringe
Cyclic feedings by infusion pump
Common Enteral Feeding Locations
Enteral Nutrition
• Nasogastric and nasointestinal tubes
– Inserted through the nasal cavity
– Radiopaque: Allowing visualization from x-ray
– ↓ likelihood of regurgitation and aspiration when
placed in intestine
– Can be dislodged by vomiting or coughing
– Can be knotted/kinked in GI tract
Tube Feeding
• Gastrostomy and jejunostomy tubes
– May be used in those needing tube feedings for
extended period
• Patient must have intact, unobstructed
GI tract
– Can be placed surgically, radiologically, or
endoscopically
Placement of Gastrostomy Tube
Percutaneous Endoscopic Gastrostomy
A, Gastrostomy tube placement via percutaneous endoscopy. Using endoscopy, a gastrostomy tube is
inserted through the esophagus into the stomach and then pulled through a stab wound made in the
abdominal wall. B, A retention disk and bumper secure the tube.
Enteral Nutrition
• Percutaneous endoscopic gastrostomy (PEG)
placement requires esophageal lumen wide
enough for endoscope.
– Fewer risks than surgical placement, lower cost,
minimum sedation
• Gastrostomy tube placement via percutaneous
endoscopy
– Using endoscopy, a gastrostomy tube is inserted
through esophagus into stomach and then is pulled
through a stab wound made in abdominal wall.
Enteral Nutrition
• Feedings can be started when bowel sounds
are present, usually 24 hours after placement.
• Immediately after insertion, tube length from
insertion site to distal end should be
measured and recorded.
• Tube should be marked at skin insertion site.
• Insertion length should be checked regularly.
Enteral Nutrition
• Tube feeding administration
– Patient position
• Patient should be sitting or lying with HOB at 30 to 45
degrees.
• HOB remains elevated for 30 to 60 minutes for
intermittent delivery.
– Tube patency
• Irrigated with water before/after each feeding, drug
administration, residual checks
• Continuous feedings administered on feeding pump
with occlusion alarm
Enteral Nutrition
– Tube position
• Placement checked before each feeding/drug administration or
every 8 hours with continuous feeds
• Methods used to check placement
– Aspiration of stomach contents
– pH check
» pH less than 5: Indicative of stomach
– Most accurate assessment: X-ray visualization
– Formula
• Commercial formulas are preferred to blend foods.
• Room/body temperature
Check gastric residual volumes.
–↑ volume leads to aspiration
Enteral Nutrition
– Administration of feedings
• Pump
– Gradually increase rate or volume over
24 to 48 hours.
• Intermittent feedings
– Volume usually 200 to 500 mL per feeding
– Administer flush water or water boluses as tolerated.
– General nursing considerations
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Daily weights
Assess for bowel sounds before feedings.
Accurate I&O
Initial glucose checks
Label with date and time started.
Pump tubing changed q24h
– Complications
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Vomiting
Diarrhea
Constipation
Dehydration
– More calorically dense, less water formula contained
– Check for high protein content.
Enteral Nutrition
• Gastrostomy or jejunostomy feedings
• Two potential problems
• Skin irritation
– Skin assessment and care
• Pulling out of tube
– Education to patient/family regarding feeding
administration, tube care, and complications
• Gerontologic considerations
– More vulnerable to complications
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Fluid and electrolyte balances
Glucose intolerance
Decreased ability to handle large volumes
Increased risk of aspiration
Obesity and Overweight
• Imbalance between energy expenditure and
energy intake, from a long-term sedentary
lifestyle and/or excessive calorie intake.
• Obesity is an abnormal increase in the size of fat
cells.
• Weight gain in adulthood is characterized
predominantly by adipocyte
hypertrophy/hyperplasia.
– Adipocyte hypertrophy is a process by which
adipocytes can increase their volume several
thousand–fold to accommodate a large increase in
lipid storage.
Obese Women
A, This woman has excessive fat deposits in her abdominal area, upper arms, and breasts. B, This woman has
excessive fat deposits in her upper arms, buttocks, and thighs. The fat distribution in both of these women is
common in obese people.
Classification of Body Weight and
Obesity
• Primary obesity (majority of obese)
– Excess caloric intake for the body’s metabolic
demands
• Secondary obesity
– Results from various congenital anomalies,
chromosomal anomalies, metabolic problems, or
CNS lesions and disorders
Classification of Body Weight and
Obesity
• Body mass index (BMI)
– Degree to which a patient is classified as
underweight, healthy (normal) weight,
overweight, or obese
– Common clinical index of obesity or altered body
fat distribution
– Uses weight-to-height ratios
BMI Chart
Body mass index (BMI) chart.
Healthy weight: BMI 18 to 24.9 kg/m2;
overweight: BMI 25 to 29.9kg/m2;
obesity: BMI ≥30 kg/m2.
BMI = weight (kg)/height (m2).
Body Shape Classification
Two general classifications used to classify people by body fat distribution are
(A) pear shape (B) apple shape.
Genetic/Biologic Basis
• Appetite is influenced by many factors that
are integrated by the brain.
– Most important, the hypothalamus
– Input to the hypothalamus is received from the
periphery from many different hormones and
peptides.
Hormones and Peptides that Interact With Hypothalamus
Some of the common hormones and peptides that interact with the hypothalamus to control and
influence eating patterns, metabolic activities, and digestion. Obesity causes a disruption in this balance
Genetic/Biologic Basis
• Adipocytes secrete enzyme, adipokines, growth
factors, and hormones.
– Contribute to development of insulin resistance and
atherosclerosis
• Greater access to food
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Prepackaged food
Fast food
Soft drinks
Increased portion sizes
• Obese individuals tend to underestimate food
and caloric intake.
• Environmental Factors
– Lack of physical exercise
• Decreased at home and work
• Advances in technology and labor-saving devices
• Increased time watching television and playing video
games
• Psychosocial Factors
– Emotional component of overeating is powerful.
– People use food for many reasons.
– Social component of eating is developed early in
life
– Birthday parties, holidays
Health Risks Associated With Obesity
• Problems occur at higher rates for obese
patients.
• Mortality rate rises as obesity increases.
– Especially with increased visceral fat
• Obese patients have a decreased quality of
life.
• Most conditions improve with weight loss.
Health Risks of Obesity
• Cardiovascular Problems
• Respiratory Problems
– Severe obesity may be associated with
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Sleep apnea
Obesity hypoventilation syndrome
↓ chest wall compliance
↑ work of breathing
↓ total lung capacity and functional residual capacity
• Diabetes Mellitus
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Hyperinsulinemia
Insulin resistance
Type 2 diabetes
Weight loss and exercise improve glucose control.
• Musculoskeletal Problems
• Osteoarthritis
– Trauma to weight-bearing joints
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Hyperuricemia
Gout
Gastroesophageal reflux disease (GERD)
Gallstones
Nonalcoholic steatohepatitis (NASH)
– Can eventually lead to cirrhosis
– Weight loss can improve NASH.
• Obesity is one of the most important known preventable causes of
cancer.
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– Breast, endometrial, kidney, colorectal, pancreas, esophagus, and
gallbladder cancers are linked to excess body fat.
Assumption behind behavior modification
– Learned disorder
– Critical difference between an obese person and a nonobese person
involves cues that regulate eating behavior.
Nutritional Therapy
• Restricted food intake is a cornerstone.
• A good weight loss plan contains food from the basic food groups.
• Diet classifications
– 800 to 1200 calories: Low calorie
– <800 calories: Very low calorie
• Adequate quantities of
– Fruits and vegetables
– Lean meat, fish, and eggs
• Fad diets should be discouraged.
– Often body water is lost, and not fat.
• Need to consider the proportion of calories from animal sources and
calories from fruits, grains, and vegetables
– American Institute for Cancer Research
• 2/3 of the diet should be plant source
• 1/3 or less from animal protein
Table 41-4. Portion Sizes: Yesterday Versus Today.
Nutritional Therapy
• Food portion sizes
– Serving of fruit and vegetables
• Size of woman’s fist or baseball
– Serving of meat
• Human’s palm or a deck of cards
– Serving of cheese
• Size of a thumb or six dice
Exercise
• An essential part of a weight control program
• Should be done daily for 30 minutes to an
hour
• Sensible forms of exercise should be
encouraged.
– Walking, swimming, cycling
Behavior Modification
• Assumption behind behavior modification
– Learned disorder
– Critical difference between an obese person and a
nonobese person involves cues that regulate
eating behavior.
• Useful basic techniques
– Self-monitoring: Show what and when foods are
eaten
– Stimulus control: Separate events that trigger
eating from the act of eating
– Rewards: Incentives for weight loss
Drug Therapy
• Classified into two categories
– ↓ food intake by reducing appetite or increasing satiety
– ↓ nutrient absorption
– Drugs that ↑ energy expenditure are not approved by the
FDA.
• Appetite-suppressing drugs
– Decrease food intake through nonadrenergic mechanisms
in the central nervous system (CNS)
• Phentermine
• Diethylpropion
• Phendimetrazine
– Not recommended because of the potential for abuse
Drug Therapy
• Appetite-suppressing drugs (cont’d)
– Serotonergic drugs ↑ release of serotonin or ↓ its uptake, thus
↓ metabolism
• Fenfluramine (Pondimin)
• Dexfenfluramine (Redux)
• Removed from market in 1997
– Mixed nonadrenergic-serotonergic agents
• Do not stimulate release of serotonin
– Sibutramine (Meridia)
• Nutrient absorption–blocking drugs
– Work by blocking fat breakdown and absorption in intestine
– Inhibit action of intestinal lipases
– Undigested fat is excreted in feces.
• Orlistat (Xenical, Alli)
Bariatric Surgery
• Used to treat obesity
• Currently the only treatment found to have a successful and lasting
impact on sustained weight loss for severely obese individuals
• Must meet all of the following criteria to be considered an ideal
candidate
– BMI ≥40 kg/m2 with one or more
obesity-related complications
– 18 years or older
– Understands the risks and benefits
– Has been obese for >5 years
– Has tried and failed to lose weight
– Has no serious endocrine problems
– Has psychiatric and social stability
– Availability of a team of health care providers
– Surgery would ↓ or eradicate high-risk conditions
Bariatric Surgery
• Three broad categories
– Restrictive
– Malabsorptive
– Combination of restrictive and malabsorptive
Bariatric Surgical Procedures
A, Vertical banded gastroplasty involves creating a small gastric pouch. B, Adjustable gastric banding uses a
band to create a gastric pouch. C, Vertical sleeve gastrectomy involves creating a sleeve-shaped stomach by
removing about 80% of the stomach. D, Biliopancreatic diversion with duodenal switch procedure creates an
anastomosis between the stomach and intestine. E, Roux-en-Y gastric bypass procedure involves constructing
a gastric pouch whose outlet is a Y-shaped limb of small intestine.
Restrictive Surgery
• Reduces the size of a stomach to 30 mL or less
• Causes patient to feel full more quickly
• Normal stomach digestion and intestinal
absorption of food
– ↓ risk of anemia and cobalamin deficiency