Download NUTRIENTS AND ENERGY METABOLISM

Parenteral Nutrition
Objectives
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To define Parenteral Nutrition Therapy
To explain parenteral nutrition components
To describe monitoring parameters of parenteral
nutrition
Definition
Parenteral nutrition is partial or total nutrition
administered intravenously. A peripheral or central vein
is used for access.
Indications:
Parenteral Nutrition
• Non-functional gastrointestinal tract
• Inability to use the gastrointestinal tract
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intestinal obstruction
peritonitis
intractable vomiting
severe diarrhea
high-output enterocutaneous fistula
short bowel syndrome
– severe malabsorption.
• Need for bowel rest
Palliative use in terminal patients is controversial.
ASPEN Board of Directors. JPEN 2002; 26 Suppl 1: 83SA
Contraindications:
Parenteral Nutrition
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Ability to consume and absorb adequate nutrients orally
or by enteral tube feeding
Hemodynamic instability
Formulas: Parenteral Nutrition
Central Parenteral Nutrition
Selection depends on caloric requirements, volume to be
administered and patient condition, as well as final
concentration of components:
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Amino acids > 5%
Dextrose > 20%
Lipids
Includes vitamins, minerals, and trace elements
Osmolality > 700 mOsm/kg H2O
Formulas: Parenteral Nutrition
Dextrose
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Provides 3.4 kcal/g
Can be the only source of energy
Dextrose infusion rate should not exceed 5 mg/kg/min
Closely related to solution osmolality
Hill GL, et al. Br J Surg 1984;71:1
Formulas: Parenteral Nutrition
Amino Acids
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Standard concentrations can vary between 5% and
15%
Energy value of amino acids (4 kcal/g)
Nitrogen (g) = protein (g) / 6.25
Sources of Protein:
Parenteral Nutrition
Customize this slide for your situation.
Indicate the available parenteral protein
solutions for your country; i.e., standard
and specialized solutions
Formulas: Parenteral Nutrition
Lipids
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Prevent essential fatty acid deficiency
Non-protein source of kcal. Recommended dose
1 g/kg/day
Available in 10%, 20% and 30% concentrations
Included as LCT or a mix of MCT/LCT at 10% and 20%
Added to basic parenteral nutrition solutions or
administered individually
Trimbo SL, et al. Nutr Supp Serv 1986;6:18
Formulas: Parenteral Nutrition
Lipids
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Less hyperglycemia
Lower concentrations of serum insulin
Less risk of hepatic damage
High doses can interfere with immune functions
High infusion rates can affect respiratory functions
Should be used with care in:
– Hyperlipidemia
– Symptomatic atherosclerosis
– Acute pancreatitis with hypertriglyceridemia
Formulas: Parenteral Nutrition
Electrolytes
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Calcium, magnesium, phosphorus, chloride, potassium,
sodium, and acetate
Forms and amounts are titrated based on metabolic
status and fluid/electrolyte balance
Must consider calcium-phosphate solubility
Alpers DH, et al., eds. In: Manual of Nutritional Therapeutics. Little, Brown and Company; 1995
Formulas: Parenteral Nutrition
Vitamins and Minerals
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In general, amounts below daily recommended intake
for healthy people, but nonetheless sufficient to cover
requirements, are added to oral or enteral formulas
Added daily to parenteral nutrition
Acute illness, infection, preexisting malnutrition, and
excessive fluid loss increase vitamin requirements
Formulas: Parenteral Nutrition
Trace Elements
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Include daily zinc, copper, chromium, and manganese
for patients with kidney or liver failure
Different requirements dictated by patient and pathology
Patients under extended parenteral nutrition require the
addition of iron and selenium
Peripheral Parenteral Nutrition
Selection of peripheral access depends on clinical situation,
requirements, tolerance to volume, and final formula
concentration
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Osmolality < 700 mOsm/kg
Total kcal limited by concentration and ratio to
volume being administered
Include ½ of the recommended electrolytes for PN
Torosian MH, ed. In: Nutrition for the Hospitalized Patient. Marcel Dekker Inc.; 1995
PN: Types of Infusion
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Continuous – Total volume of formula is administered
over a 24 hour period
Cyclic – Volume is administered in one period, with
infusion adjustments and a period of rest
Selection of infusion type depends on patient’s
condition
Use a parenteral infusion pump
Monitoring Patient on Parenteral
Nutrition
Metabolic
Assessment
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Glucose
Fluid and electrolyte balance
Renal and hepatic function
Triglycerides and cholesterol
Body weight
Nitrogen balance
Plasma protein
Creatinine/height
index
Campbell SM, Bowers DF. Parenteral Nutrition. In: Handbook of Clinical Dietetics.
Yale University Press, 1992
Summary
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Parenteral nutrition supplies partial or total nutrition by
venous access
Total parenteral nutrition components supply all required
nutrients
Metabolic monitoring and changes in solution
components are needed to maintain adequate
metabolic balance