Parenteral NutritionParenteral Nutrition

Objectives

• 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

– 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

• 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:

•Amino acids > 5%•Dextrose > 20%•Lipids•Includes vitamins, minerals, and trace elements•Osmolality > 700 mOsm/kg H2O

Formulas: Parenteral Nutrition

Dextrose

• 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

• 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

• 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

• 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

• 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

• 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

• 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

•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

• 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

• Glucose• Fluid and electrolyte balance• Renal and hepatic function• Triglycerides and cholesterol

Campbell SM, Bowers DF. Parenteral Nutrition. In: Handbook of Clinical Dietetics. Yale University Press, 1992

Assessment

• Body weight• Nitrogen balance• Plasma protein• Creatinine/height

index

Summary

• 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