Download Specialized Nutrition Support: Enteral & Parenteral Nutrition

Specialized Nutrition
Support:
Enteral & Parenteral Nutrition
Chapter 16
Nutrition & Diet Therapy (7th Edition)
Need for Nutrition Support
• Nutrition support may be
required to meet patient’s
nutritional needs
– Patients often too ill to
obtain energy & nutrients
by consuming foods
– Or illness may interfere
with eating, digestion or
absorption
Nutrition & Diet Therapy (7th Edition)
• Nutrition support: delivery
of formulated nutrients by
feeding tube or
intravenous infusion
• Enteral nutrition:
supplying nutrients using
GI tract, including tube
feedings & oral diets
• Parenteral nutrition:
intravenous provision of
nutrients, bypassing the GI
tract
Selecting a Feeding Route
Nutrition & Diet Therapy (7th Edition)
Enteral Nutrition Support
• Wide selection of enteral formulas, designed to
meet variety of medical & nutritional needs
• May be used alone or in conjunction with other
foods
• Many formulas can provide all of nutrient
requirements if consumed in sufficient volume
• Classified according to macronutrient composition
• Preferred over intravenous feedings
Enteral nutrition
requires intact &
normal GI function
Nutrition & Diet Therapy (7th Edition)
Types of Enteral Formulas
• Standard formula: for patients who can digest &
absorb nutrients without difficulty; contains
protein & carbohydrate sources
• Hydrolyzed formulas: used for patients with
compromised digestive or absorptive functions—
macronutrients are partially or fully broken down
& require little, if any, digestion before absorption
• Disease-specific formulas: designed to meet
nutrient needs of patients with particular
disorders: liver, kidney, lung diseases, glucose
intolerance, metabolic stress
• Modular formulas: contain only one or two
macronutrients; used to enhance other formulas
Nutrition & Diet Therapy (7th Edition)
Enteral Nutrition in Medical
Care
• Oral use
– Supplement diet when
food consumption does
not meet need
– Reliable source of
nutrients & energy
– Taste important
consideration
• Tube feedings
– Used when patient
cannot consume
enough food or formula
orally
– Feeding delivered
directly to stomach or
intestine
Nutrition & Diet Therapy (7th Edition)
• Patients can drink enteral
formulas when they are
unable to consume enough
food from a conventional diet
Enteral Nutrition in Medical
Care (con’t)
• Candidates for tube feedings:
– Severe swallowing difficulties
– Little or no appetite for extended periods, especially if
malnourished
– GI obstructions, impaired motility of the upper GI tract
– After intestinal resection, beginning enteral feedings
– Mentally incapacitated due to confusion, dementia,
neurological disorders
– Individuals in coma
– Individuals with extremely high nutrient requirements
– Individuals on mechanical ventilators
Nutrition & Diet Therapy (7th Edition)
Enteral Nutrition in Medical
Care (con’t)
• Feeding routes
– Selected on basis of medical condition,
expected duration, potential complications of a
particular route
– Main routes:
• Transnasal (temporary)
– Nasogastric
– Nasoduodenal
– Nasojejunal
• Gastrostomy
• Jejunostomy
Nutrition & Diet Therapy (7th Edition)
Enteral Nutrition in Medical
Care (con’t)
• Formula selected after assessment of the
diagnosis, patient’s age, medical
problems, nutritional status, ability to
digest & absorb nutrients
• Nutrition-related factors influencing
formula selection
– Energy, protein & fluid requirements
– Need for fiber modifications
– Individual tolerances (food allergies &
sensitivities)
Nutrition & Diet Therapy (7th Edition)
Enteral Nutrition in Medical
Care (con’t)
• Administration of tube
feedings
– Safe handling
• Open feeding system
• Closed feeding system
• Safety guidelines
– Review of procedure
with patient & family
– Verification of tube
placement (Xray)
– Formula delivery
• Intermittent feedings
(bulk over 20-40 min)
• Continuous feedings
(pump)
• Bolus feeding (one or
several “shots”)
Nutrition & Diet Therapy (7th Edition)
• Open feeding system:
requires formula to be
transferred from original
packaging to feeding
container
• Closed feeding system:
formula prepackaged in
ready-to-use containers
• Intermittent feeding: delivery
of prescribed volume over 2040 minutes
• Continuous feeding: slow
delivery at constant rate over
8-24 hour period
• Bolus feeding: delivery of
prescribed volume in less
than 15 minutes
Enteral Nutrition in Medical
Care (con’t)
• Formula volume & strength
– Procedures vary by institution
– Almost all patients can receive undiluted isotonic or hypertonic
formulas
– Generally started slowly and volume gradually increased
• Rate & amount of increase depend on patient’s tolerance
• Continuous feedings may be better tolerated than
intermittent feedings
• Checking gastric residual volume
(vol. of formula in stomach after fdg.)
– Volume of formula remaining in stomach from previous feeding
– Evaluate if gastric residual >200 mL
– If tendency to retain persists, physician may consider intestinal
feedings or drug therapy to stimulate gastric emptying
Nutrition & Diet Therapy (7th Edition)
Enteral Nutrition in Medical
Care (con’t)
Meeting water needs
•
•
•
Adults require about 2000 mL of
water daily
– Fluid intake may be restricted for
patients with kidney, liver or
heart disease
– Fluid intake may be increased
with fever, high urine output,
diarrhea, excessive sweating,
severe vomiting, fistula drainage,
high-output ostomies, blood loss,
open wounds
Standard formulas contain about
85% water (about 850 mL/liter);
nutrient-dense formulas contain
about 69-72% water
Meet fluid needs with additional
water flushes
Nutrition & Diet Therapy (7th Edition)
Estimating fluid
requirements
Adults: 30-40 mL/kg;
30 mL/kg for older
adults
Children: 50-60 mL/kg
Infants: 150 mL/kg
Enteral Nutrition in Medical
Care (con’t)
• Transition to table foods
– Volume of formula is tapered off as
condition improves
– Gradual shift to oral diet
• Begin drinking same formula that is
delivered by tube
• Oral intake should supply about 2/3 of
nutrient needs before tube feedings
discontinued
Nutrition & Diet Therapy (7th Edition)
Enteral Nutrition in Medical
Care (con’t)
• Giving Medication through feeding tubes
– Potential for diet-drug interactions must be
considered before administration
– Continuous feeding halted for approximately
15 minutes before & 15 minutes following
medication delivery (longer for some
medications)
– Type of medication may make tube
administration impossible—require change to
alternate route
• Generally best to administer medications by
mouth whenever possible
Nutrition & Diet Therapy (7th Edition)
Enteral Nutrition in Medical
Care (con’t)
• Complications of tube feedings
– Gastrointestinal problems: nausea, diarrhea
– Mechanical problems related to tube feeding process
– Metabolic problems: biochemical alterations & nutrient
deficiencies
• Many complications preventable with appropriate
feeding route, formula & delivery method
• Close attention to patient’s medical condition &
medication use is important (follow up/reassessment)
– Monitor weight, hydration status
– Verify lab test results
Nutrition & Diet Therapy (7th Edition)
Parenteral Nutrition Support
• Indicated for patients
who do not have
functioning GI tract &
who are malnourished
(or likely to become so)
• Used when enteral
formulas cannot be used
or intestinal function is
inadequate
• Life-saving option for
critically-ill persons
• Two main access sites:
central or peripheral
vein
Nutrition & Diet Therapy (7th Edition)
–
–
–
–
–
–
–
–
Indications
Short-bowel syndrome
Severe pancreatitis
Malabsorption disorders
Intestinal obstruction or
fistula
Severe burns or trauma
Critical illnesses or
wasting disorders
Bone marrow transplant
Malnourished with
high risk for aspiration
Venous Access
• Peripheral parenteral nutrition (PPN)
– Can only provide limited amounts of energy &
protein
– Peripheral veins can be damaged by overly
concentrated solutions
– Limited to patients who do not have high
nutrient needs or fluid restrictions
– Used most often for short-term nutrition
support (7-10 days)
– Rotation of vein sites may be necessary
Nutrition & Diet Therapy (7th Edition)
Venous Access (con’t)
• Total parenteral nutrition (TPN)
– Can reliably meet complete nutrient
requirements
– Provides nutrient-dense solutions for
patients with high nutrient needs or fluid
restrictions
– Preferred for long-term intravenous
feedings
– Inserted directly into a large central vein
Nutrition & Diet Therapy (7th Edition)
Parenteral Solutions
• Customized formulations to meet patients’
nutrient needs
• Highly individualized; often recalculated
on daily basis until patient’s condition
stabilizes
• Contents:
–
–
–
–
–
Amino acids (both essential and non-essential for protein)
Carbohydrates (dextrose)
Lipid emulsions
Fluid & electrolytes
Vitamins & trace minerals
Nutrition & Diet Therapy (7th Edition)
Administering Parenteral
Nutrition
• Multidisciplinary nutrition support
team of health care professionals
– Physicians
– Nurses
– Dietitians
– Pharmacist
• Potential complications related to
venous line & metabolic problems
Nutrition & Diet Therapy (7th Edition)
Administering Parenteral
Nutrition (con’t)
• Administration procedures
– Insertion & care of intravenous catheters
– Administration of parenteral solutions
• Continuous administration -24 hours/day
• Cyclic administration – 10 to 16 hour periods
– Monitoring patient condition, nutritional status,
complications
– Discontinuing of feedings-when GI function
returns
Nutrition & Diet Therapy (7th Edition)
Nutrition Support at Home
• Continuation of nutritional support (tube feedings
or parenteral nutrition) after medical condition
has stabilized
• Candidates for home nutrition support
– Long-term nutrition care required for chronic conditions
– Users intellectually capable of learning procedures,
monitoring treatment & managing complications
• Planning for home nutrition
– Involvement of users in decision making to ensure longterm compliance & satisfaction
– Assessment & evaluation of type of feeding, equipment,
resources, ability to perform procedures
Nutrition & Diet Therapy (7th Edition)
Nutrition Support at Home
(con’t)
• Quality of life issues
– Lifestyle adjustments
may cause struggle for
patients & families
– Economic impact
– Time & other demands
associated with
treatment
– Physical difficulties,
including disrupted
sleep
– Social issues
– Life-sustaining therapy
associated with serious
complications
Nutrition & Diet Therapy (7th Edition)
• Portable pumps & convenient
carrying cases allow people
who require home nutrition
support to move about freely
Nutrition in Practice—Inborn
Errors of Metabolism
• Inborn error of metabolism:
inherited trait, caused by genetic
mutation
• Results in absence, deficiency or
malfunction of a protein that has a
critical metabolic role
Nutrition & Diet Therapy (7th Edition)
Nutrition in Practice—Inborn
Errors of Metabolism (con’t)
• Medical nutrition therapy is primary treatment for
many inborn errors that involve nutrient
metabolism
• Dietary intervention generally involves restriction
of substances that cannot be metabolized or
supplying substances that cannot be produced
• Dietary changes may improve outcomes
– Preventing accumulation of toxic metabolites
– Replacing deficient nutrients
– Providing a diet that supports normal growth &
development & maintains health
• Some inborn errors may require treatment other
than or in addition to dietary changes
Nutrition & Diet Therapy (7th Edition)
Nutrition in Practice—Inborn
Errors of Metabolism (con’t)
• Phenylketonuria (PKU)
– Metabolic disorder affecting amino acid metabolism
– Missing or defective protein is liver enzyme that
converts the essential amino acid phenylalanine to
tyrosine
– Phenylalanine & metabolites accumulate and damage
developing nervous system—most debilitating effect is
on brain development
– Diagnosed within first few days following birth—infants
routinely screened in all 50 states
– Treatment consists of lifelong diet restricting
phenylalanine & supplying tyrosine; allowing blood
levels of these amino acids to be maintained within safe
ranges
Nutrition & Diet Therapy (7th Edition)
Nutrition in Practice—Inborn
Errors of Metabolism (con’t)
• Managing PKU
– Central to PKU diet is enteral formula that is
phenylalanine-free & supplies energy, amino acids,
vitamins & minerals
– Formula requirements must be recalculated periodically
to accommodate growing infant’s shifting needs for
protein, phenylalanine, tyrosine & energy
• Careful monitoring of foods containing phenylalanine
• Monitoring of growth rates & nutrition status
– Parents & children may need to develop creative ways to
make diet enjoyable
Nutrition & Diet Therapy (7th Edition)
Nutrition in Practice—Inborn
Errors of Metabolism (con’t)
• Galactosemia
– Inborn error of carbohydrate metabolism
– Deficiency of enzyme needed to metabolize galactose
– Accumulation of galactose can result in damage to
multiple tissues
• Reaction with severe vomiting & jaundice within days
of initial feeding of infant
• Serious liver damage may result, progressing to
symptomatic cirrhosis
• Other complications: kidney failure, cataracts, brain
damage
– Delay in treatment can result in irreversible brain
damage
Nutrition & Diet Therapy (7th Edition)
Nutrition in Practice—Inborn
Errors of Metabolism (con’t)
• Managing galactosemia
– Main focus of diet is exclusion of milk & milk
products (elimination of galactose)
– Avoidance or restriction of other galactosecontaining foods
• Organ meats
• Some legumes, fruits & vegetables
– Food lists help patients to identify galactose
content of common foods
– Complications may develop despite compliance
with diet therapy
Nutrition & Diet Therapy (7th Edition)