1. Indications

a. Used to provide partial or total nutritional support in patients who cannot absorb and digest oral or enteral tube-delivered nutrients, or when central PN is not feasible

b. Used in patients who cannot be fed by the oral or enteral route, requiring nutritional support by the parenteral route for anticipated therapy of 7 to 10 days

c. Used as supplemental nutritional support to oral or enteral nutrition or as a transition to enteral nutrition

d. Used as transitional support until PN can be initiated or resumed

e. Used in patients for whom central venous access is either impossible or contraindicated

2. Specific pediatric indications

a. Indications are similar to those for adults

1) PPN is suggested for nonstressed infants for brief courses of maintenance therapy when full growth and development are not the primary goal

2) Central PN is a more logical choice for supporting normal growth and maintaining body composition

b. Generally used for nutrition support for a short time (as long as 2 weeks) because of limited access to peripheral veins: in older infants and children, nutrition repletion or aggressive nutrition support may be possible by this route, except in patients requiring fluid restriction

3. Contraindications

a. Long-term support is needed

b. Poor or inaccessible peripheral venous access

c. Severe malnourished state

d. Large volumes of fluid cannot be tolerated

e. Nutrient needs are greater than what can be safely met with PPN

f. Functional gastrointestinal tract

g. Refusal by patient or legal guardian

1. Indications

a. Necessary when parenteral feeding is indicated for longer than 2 weeks, peripheral venous access is limited, nutrient needs are large, or fluid restriction is required and the benefits of PN support outweigh the risks

b. Used for patients requiring intravenous nutrition as the primary or supportive therapy

1) PN is frequently indicated for patients with disease states that result in impaired ability to digest nutrients by the oral or enteral routes in quantities sufficient to satisfy nutritional requirements

c. Used in disease states in which the use of PN may be indicated as a primary therapy

1) Short gut syndrome

2) Enterocutaneous fistula

3) Selected cases of allogenic bone marrow transplant, acute exacerbation of Crohn’s disease, severe necrotizing pancreatitis, and intractable nausea with vomiting

4) Prolonged ileus or distal obstruction

d. There are other disease states in which PN may be indicated as supportive therapy or conditions in which the efficacy of PN has not been clearly demonstrated (e.g., inflammatory bowel disease, anorexia nervosa)

e. The use of PN for cancer support, sepsis, trauma, and general perioperative support may be appropriate in selected situations

2. Specific pediatric indications

a. Disease states that affect the pediatric populations as outlined for adult

b. Extremely premature infant

c. Disorders of the respiratory system

d. Disorders of the gastrointestinal tract

1) Congenital anomalies

2) Surgical conditions

3) Intractable diarrhea of infancy

4) Inflammatory conditions

5) Neuromuscular disorders

e. Hypercatabolic states

3. Contraindications

a. Functional gastrointestinal tract

b. Sole dependence on PN is clearly <5 days

c. Inability to obtain central venous access

d. Prognosis does not warrant aggressive nutritional support

e. Refusal by patient or legal guardian

f. Risks of PN outweigh its benefits

g. Minimal stress and trauma or the immediate postoperative or poststress periods in a well-nourished patient when it is anticipated that convalescence will be short and the gastrointestinal tract can be used within 7 to 10 days

h. Malnutrition caused by a rapidly progressive disease not amenable to curative or palliative therapy; disease is proven or suspected of being untreatable

1. Nutrients: constituents in food that supply the body with its necessary elements

a. Certain nutrients (carbohydrates, fats, proteins, and alcohol) provide energy b Other nutrients (water, electrolytes, minerals, and vitamins) are essential to the metabolic process

2. Nutritional status

a. The condition of the body resulting from the utilization of the essential nutrients available to the body

b. Nutritional status depends on the quality and quantity of nutrients consumed, the relative need for nutrients, and the ability of the body to use nutrients

3. Nutritional deficiency

a. Occurs when adequate amounts of essential nutrients required for proper functioning are not provided to the body tissues; may be primary or secondary

b. Primary deficiency occurs when the diet is deficient in a particular nutrient or nutrients

c. Secondary deficiency results from impairment in normal digestion, absorption, and use of essential nutrients, resulting in nutrient deficiency; this may occur despite adequate ingestion or metabolic stress

1. Classification

a. Patients should be considered malnourished or at risk for malnutrition if they have inadequate nutrient intake for ≥7 days or if they have weight loss ≥10% of their body weight within 6 months or >5% in 1 month

b. The most common causes of malnutrition are protein and calorie deficiencies

c. Three types of protein-calorie malnutrition have been identified: marasmus, kwashiorkor, and marasmus-kwashiorkor; it is important to determine the nature and severity of protein-calorie depletion so that appropriate nutritional support can be given

2. Marasmus—simple starvation

a. Characteristics

1) A gradual wasting of adipose and somatic muscle with preservation of visceral proteins; the patient is cachectic

2) Chronic condition in which basal metabolic rate (BMR) is reduced; fat is the major energy substrate, and visceral proteins are preserved

3) Presents with weight loss, adipose and skeletal muscle atrophy, decreased anthropometric measurements, and development of immune incompetence, which is accompanied by decreased total lymphocyte counts and skin test energy

b. Causes

1) Occurs when there is an acceptable ratio of protein-caloric intake but inadequate total dietary intake

2) Seen with prolonged starvation, anorexia, chronic illness, old age

c. Goal of therapy: to restore fat and protein stores over a prolonged period

3. Kwashiorkor—protein dysmetabolism or hypoalbuminemia

a. Characteristics

1) Presents with increase in extracellular water spaces, pitting edema, salt retention, occasionally ascites, and anasarca

2) Visceral protein stores are depleted, with depressed concentrations of serum albumin, transferrin, thyroxin-binding prealbumin, and retinol-binding protein

3) Immunocompetence is impaired, and the patient is susceptible to infection

b. Causes

1) Caloric intake is adequate or excessive, but diet consists of almost all carbohydrates with little or no protein

2) Seen during periods of decreased protein intake accompanied by increased carbohydrate intake (e.g. liquid diets, fad diets, long-term use of intravenous fluids containing dextrose)

c. Goal of therapy: to preserve the remaining protein stores

4. Marasmus-kwashiorkor

a. Characteristics

1) Presents with skeletal muscle and visceral protein wasting, depleted fat stores, immune incompetence; individuals appear cachectic, and are usually undergoing acute catabolic stress; can also present with vitamin and mineral deficiencies

2) Associated with the highest risk of morbidity and mortality

b. Causes

1) Individuals share some aspect of both marasmus and kwashiorkor

2) Two phases of abnormal dietary intake occur: initial reduced protein intake with subsequent decreased total intake or vice versa

3) May occur in hospitalized patients with pre-existing marasmus complicated by hospital-induced kwashiorkor resulting from administration of intravenous dextrose solutions or metabolic stress imposed on an individual with pre-existing malnutrition

c. Goal of therapy: restore protein and fat stores

1. The requirement for a nutrient is the minimum intake that will maintain normal function and health

2. The United States standard for determining nutrient intake and diet evaluation dates back to 1941 and the establishment of the Recommended Daily Allowance or RDA. Since 1995, a joint effort by the US and Canada has lead to a single set of references now known as the Dietary Reference Intakes or DRI. These reference intakes address the needs of healthy individuals as opposed to those with disease. DRI are divided into four categories:

a. Estimated average requirement or EAR: estimated to meet the requirements of half of healthy individuals in a particular group (gender and age)

b. RDA: recommended daily allowance that meets the needs of all individuals

c. Adequate intake or AI: average intake of a group that seems to sustain a defined nutrient state

d. Tolerable upper intake level or UL: the maximum intake that is unlikely to pose a health problem

1. Positive balance exists when food intake exceeds expenditure; excess energy is stored primarily as fat, and weight gain results

2. Negative balance exists when energy expenditure exceeds food intake; weight loss results as the body uses its own energy stores to meet the requirements

3. Equilibrium exists when energy in food equals energy expended; body weight remains constant

1. Energy requirements are dependent on a number of factors, which include the body surface area (derived from height and weight), age, and gender; they are usually estimated from tables or from simple formulas

2. Energy expenditure

a. Total daily energy (TDE) expenditure has three components:

1) Basal energy expenditure (BEE) or basal metabolic rate (BMR)

2) Energy expenditure is related to activity

3) Specific dynamic action (SDA) of food

b. Determination of energy needs can be determined from the BEE or resting metabolic expenditure (RME); BEE is the amount of energy produced per unit of time under “basal” conditions; RME is the amount of energy expended at any time other than during basal conditions but with the patient at thermal neutrality

1) The terms BEE and RME frequently are used interchangeably; however, RME is usually approximately 10% higher than BEE in healthy persons

2) BEE accounts for 65% to 75% of energy expenditure and may be measured or estimated

3) The traditional method used to estimate BEE is the Harris-Benedict equation, which takes into consideration the patient’s weight in kilograms, height in centimeters, age, and gender

4) May be modified for activity factors (AF) and injury factors (IF)

5) A simpler, widely accepted method used to estimate daily adult caloric requirements is to use 20 to 35 calories/kg/day

6) Two methods are available to measure the BMR: direct or indirect calorimetry; the term calorimetry derives from heat metabolism

c. Energy expenditure of activity: the second largest component of daily energy expenditure. Energy requirement can vary from 1.1 to 10.3 kcal/kg/hour, depending on the type of activity

d. SDA of food: the increased heat production that occurs with food ingestion or infusion of parenteral nutrients: add 10% to the sum of BMR plus energy expenditure of activity to account for SDA

1. Classifications

a. Amino acids are the basic units of protein; there are essential and nonessential amino acids

1) Essential amino acids cannot be synthesized in the body and must be received in the diet

2) Nonessential amino acids can be synthesized by the body

3) Conditionally essential amino acids are nonessential under normal circumstances but are required in the diet during certain disease states because use exceeds synthesis

b. The amino acids are also classified as aromatic amino acids (AAA) or branched-chain amino acids (BCAA)

1) BCAAs are oxidized principally by skeletal muscle

2) The rate of oxidation of BCAAs in muscle is stimulated by stress, fasting conditions associated with muscle protein wasting, and negative nitrogen balance

c. Essential amino acids: isoleucine (BCAA), leucine (BCAA), lysine (AAA), methionine (AAA), phenylalanine (AAA), threonine (AAA), tryptophan (AAA), valine (BCAA)

d. Conditionally essential amino acids: histidine, cysteine, tyrosine, arginine, glutamine

e. Nonessential amino acids: alanine, aspartic acid, asparagine, glutamic acid, glycine, proline, serine

2. Function

a. The major function of protein is contributing to tissue growth, repair, and replacement of all body cells

b. Proteins are components of the body’s defense mechanism and are found in antibodies, scar tissue, and clots; the body’s functional molecules (enzymes, hormones, and carrier substances) require protein for development

c. Although protein can contribute to energy needs (approximately 4 kcal/g), this is not its major purpose

3. Metabolism

a. Body protein is constantly being turned over by the process of synthesis and catabolism, with approximately 40% of the body’s resting energy expenditure used for these processes

1) During periods of inadequate nutrient intake, mobilization and catabolism (breakdown) of the body’s protein compartment occur to supply energy substrate as glucose

2) A positive balance of calories and nitrogen is needed to promote anabolism (build-up)

b. There is no storage form of amino acids other than the body muscle mass

c. The amino acids released as a result of skeletal muscle catabolism are the main sources of nitrogen, which is released in the urine as urea

d. Factors regulating the rate of metabolism, such as extreme environmental stress, infection, fever, trauma, and surgical procedures, can result in substantial urinary loss of nitrogen

1) In illness or trauma that has led to severe protein depletion, protein requirements for repletion of wasted tissues are increased; this is similar to the process that occurs in infants and children who are in a state of rapid growth

2) The degree of stress, possible hypercatabolic state, and special clinical conditions such as renal failure and hepatic insufficiency affects protein need and tolerance

4. Protein compartments: the body’s protein resides in two compartments

a. Somatic compartment: includes skeletal muscle, skeleton, and skin-supporting structure

b. Visceral compartment: includes solid viscera and secretory proteins

5. Requirements

a. Protein needs are determined according to the results of nitrogen balance studies

1) Predicted protein requirements are equated with the lowest quantity of protein needed to maintain health and nitrogen equilibrium

2) An important objective is to maintain a positive nitrogen balance

b. Requirement is dependent on a number of metabolic factors, such as the previous nutritional status, degree of nutritional depletion, provision of nonprotein energy, and the rate of desired repletion. Requirements increase in certain states (athletic training, growth, and pregnancy) or in catabolic states (stress and trauma)

c. Providing nonprotein calories to meet the energy needs will promote nitrogen retention

d. 1 g nitrogen is equal to 6.25 g of protein

e. Effective nitrogen supplementation during PN is based on the following requirements for the adult patient:

1) Maintenance: 0.8 to 1.0 g/kg/day

2) Catabolic patients: 1.2 to 2.0 g/kg/day

3) Chronic renal failure: 1.5 to 1.8 g/kg/day

4) Acute renal failure and catabolic state: 1.5 to 1.8 g/kg/day

5) Critically ill patients: 2.0 g/kg/day may be required

f. Pediatrics

1) Child older than 12 months: 1.0 to 1.6 g/kg/day

2) Infants: 1.6 to 2.2 g/kg/day

1. Definition: organic compounds composed of carbon, hydrogen, and oxygen

2. Serve as the major source of energy in humans

3. Types

a. Dextrose (glucose)

1) Is the primary source of carbohydrate calories in PN solutions

2) Is a physiologic substrate, easily purified for intravenous administration, inexpensive, and can be provided in high concentrations

3) 1 g dextrose provides approximately 3.4 calories

b. Fructose

1) Naturally occurring monosaccharide that offers an alternative to dextrose as a source of carbohydrate calories

2) Fructose does not require insulin for conversion to glucose; however, most adult tissues cannot use fructose directly and require its conversion to glucose in the liver

3) Hyperglycemia and glycosuria occur less frequently with fructose than with corresponding amounts of glucose

4) Rapid infusion of fructose has been associated with lactic acidosis, hypophosphatemia, elevated serum bilirubin and uric acid levels, and depletion of hepatic adenine nucleotides

c. Sorbitol and xylitol

1) Alcohol sugars that are only partially insulin independent

2) Both require conversion to glucose in the liver and are associated with numerous toxic effects, including lactic acidosis, hepatic failure, and hyperuricemia

d. Glycerol

1) Naturally occurring sugar alcohol that provides 4.3 calories/g

2) The use of glycerol as an exclusive energy source is relatively recent and requires further clinical investigation

4. Functions

a. Major function is as an energy-providing nutrient

b. Carbohydrate is protein sparing; when the body does not receive sufficient energy calories it will turn to breaking down protein and fat stores for energy

5. Metabolism

a. When glucose is supplied as a nutrient, the quantity not immediately used for energy calories is stored in the liver and muscle as glycogen

1) Glycogen is the storage form of glucose

2) When glycogen storage capacity is exhausted, excess carbohydrate is stored as fat

b. Carbohydrate metabolism, like all forms of metabolism, has a constructive phase called anabolism and a destructive phase called catabolism

1) The three major processes involved in carbohydrate catabolism are glycolysis (initial process in which sugar is broken down into simpler compounds), the Krebs cycle (completed carbohydrate catabolism), and glycogenolysis (conversion of glycogen stores into glucose)

2) The two major processes involved in carbohydrate anabolism include glycogenesis (glucose converted to glycogen) and gluconeogenesis (transformation of fats and proteins into glucose or glycogen for use by cells for fuel)

c. Rate of glucose metabolism varies between 0.4 and 1.4 g/kg/hour; maximum glucose use rate is approximately 5 mg/kg/minute. Overfeeding by supplying glucose in excess of this rate does not further accentuate nitrogen retention and produces adverse effects such as fatty liver and increased carbon dioxide production, which may aggravate pre-existing respiratory distress

6. Requirements

a. There is no specific requirement for carbohydrates

1) Individual requirements are determined by estimating or measuring energy requirements

2) It can be synthesized from amino acids and glycerol by gluconeogenesis, although it is preferable to ingest carbohydrates

b. Carbohydrates are generally used to provide at least 50% of total calories

1. Definition: biologic substance soluble in organic solvents and insoluble in water

2. Types

a. Essential fatty acids

1) Linoleic acid is the primary essential fatty acid required for growth

2) Linolenic acid may not be essential for adults, but it may be essential for proper visual and neural development and in certain disease states

b. Major lipid substances within the body include triglycerides, phospholipids, cholesterol, and fatty acids

3. Functions

a. Responsible for a wide range of metabolic and structural functions

b. Essential for structural integrity of cell membranes and is necessary for absorption of fat-soluble vitamins

c. In PN, lipids are a major source of metabolic fuel and a source of essential fatty acids

4. Metabolism

a. The most concentrated source of heat and energy, providing more than twice as many energy calories per gram (9 kcal/g) as either protein or carbohydrates; fat stores are a reserve of body energy that is mobilized when necessary

b. Lipids are isotonic and can be infused in peripheral veins

c. Allows a decrease in the concomitant intake of glucose and a reduction in the complications associated with large glucose loads in critically ill patients

d. There are lower levels of circulating insulin in lipid-containing PN preparations

5. Requirements

a. The main purpose of intravenous fat is to prevent the onset of essential fatty acid deficiency (EFAD), manifested as dermatitis, hemolytic anemia, thrombocytopenia, impaired wound healing, and hepatic dysfunction secondary to fatty metamorphosis

b. There is no recommended dietary allowance for fat as a nutrient in the diet; EFAD can occur in as little as 5 days without fat supplementation

c. The minimum human requirement needed to prevent EFAD should represent 2% to 4% of the total caloric intake

d. The optimum dose of lipid for the provision of calories is not known

1) Most patients receive 10% to 40% of the daily caloric intake, 2.5 g/kg for adults or 4 g/kg for pediatric patients

2) The standard distribution of nonprotein calories is 70% to 85% as carbohydrates and 15% to 30% as fat. There is limited clinical benefit when the fat content exceeds 30% of nonprotein calories in PN

1. Requirements

a. Maintenance: 30 to 35 mL/kg/day or 1,500 mL for the first 20 kg plus 20 mL/kg for actual weight beyond 20 kg

b. Factors increasing requirements: extraordinary exogenous losses (e.g., fistulas, diarrhea, nasogastric tube drainage)

2. Fluid changes induced by starvation

a. Extracellular fluid (ECF)

1) Most of early water loss in starvation originates from ECF

2) If fasting continues, loss of ECF is markedly reduced

3) Water and sodium are conserved, and catabolism of body cell mass results in a proportionally high extracellular water content

b. Intracellular fluid

1) Oxidation of cell substrates results in net production of free water

2) Water normally bound to macromolecules, such as glycogen and protein, is free to diffuse to the ECF

3. Fluid changes induced by acute injury

a. Acute injury is followed by characteristic fluid and electrolyte distortions that tend to maintain plasma volume and tissue perfusion

b. Sodium and water retention occurs along with the formation of third spaces in injured areas or in the gastrointestinal tract

4. Fluid changes induced by PN

a. Fluid overload can occur if PN is administered with a predetermined number of calories without regard for the volume infused

b. To prevent fluid overload, the concentration of glucose calories can be increased, or fat needs to be added as a caloric source

1. Considerations

a. The following factors should be considered when determining the electrolyte requirements for a patient receiving PN:

1) Pre-existing electrolyte deficits

2) Excessive fluid and electrolyte losses

3) Daily electrolyte needs

4) End organ function, especially renal function

b. With protein-calorie malnutrition, there is loss of the intracellular ions, potassium, magnesium, and phosphorus, together with a gain in sodium and water

c. It is necessary to give potassium, magnesium, phosphorus, and zinc to ensure optimum nitrogen retention

2. Sodium

a. Recommendations/requirements

1) Daily needs range from 100 to 150 mEq (1 to 2 mEq/kg)

2) Supplement to cover abnormal losses

b. Considerations related to PN

1) Abnormalities of sodium commonly linked to fluid administration

2) Serum sodium concentrations in the acute phase may not reflect actual body sodium, but rather hyper- or hypovolemic states

3) Less sodium may be required in patients with renal or cardiovascular disease

3. Potassium

a. Recommendations/requirements: daily needs range from 80 to 100 mEq (1 to 2 mEq/kg); an anabolic patient may require 150 to 200 mEq/day

b. Considerations related to PN

1) Glucose infusions will increase the need for potassium

2) Approximately 3 mEq are retained with each gram of nitrogen

4. Chloride

a. Recommendations/requirements: add quantity similar to total sodium content

b. Considerations related to PN

1) To prevent hyperchloremic metabolic acidosis, crystalline amino acid formulations are acetate-balanced, with acetate substituted as an anion, and chloride is maintained in a 1:1 ratio with sodium

2) Hypochloremic metabolic acidosis remains a risk in patients undergoing sustained gastric losses

5. Phosphorus

a. Recommendations/requirements

1) 20 to 40 mmol/day

2) Increases when glucose alone is given as a source of energy; this is partly because lipid emulsions have phospholipids that act as an additional source of phosphorus, and high insulin levels associated with the glucose system increase cellular uptake of phosphorus

b. Considerations related to PN

1) Hypophosphatemia is commonly found during the initial phase of nutritional support in previously debilitated, malnourished patients.

2) With refeeding, there is a redistribution of phosphate into muscle, which can induce hypophosphatemia; signs and symptoms include tremors, paresthesias, ataxia, decreased platelet and erythrocyte survival, impaired leukocyte function, and weakness. This has been termed refeeding syndrome

6. Calcium

a. Recommendations/requirements: 10 to 15 mEq/day

b. Considerations related to PN

1) Administration of large amounts of phosphate salts can contribute to a lowering of serum calcium levels

2) In contrast, administration of intravenous phosphate and acetate-balanced solutions has been shown to decrease hypercalciuria and may be beneficial in maintaining calcium stores in patients receiving long-term PN

3) In malnourished patients, serum calcium levels may be low as a result of decreased levels of albumin to which half of calcium is bound, whereas ionized calcium levels remain normal

4) Calcium (and phosphate) dosages that are added to PN may be limited due to the risk of precipitate formation

7. Magnesium

a. Recommendations/requirements

1) 8 to 20 mEq/day

2) Additional amounts may be required to cover losses from gastrointestinal secretions

b. Considerations related to PN

1) Inadequate replacement aggravated by high losses can lead to clinical syndrome of hypomagnesemia (muscle weakness, fatigue, convulsions, nystagmus [abnormal lateral eye movements])

2) Renal potassium and phosphate losses are increased by hypomagnesemia

1. Definition

a. Trace elements are found in the body in minute amounts; dosage parameters to meet basic requirements are usually very small (in milligrams)

b. Each trace element is a single chemical and has an associated deficiency state; functions of trace elements are many, and often their actions are synergistic

2. Iron

a. Uses/function

1) Predominant function is oxygen transport

2) Lowered serum iron observed in malnourished patients may be secondary to defects in iron mobilization, rather than lowered whole body stores

3) The body has a large capacity to store iron in usable nutritional reserves and has limited potential to excrete excesses

4) There are potential problems associated with compatibility, bioavailability, and administration with PN solutions

b. Signs/symptoms of deficiency

1) Pallor, fatigue, exertional dyspnea, tachycardia, headache, listlessness, paresthesias, glossitis, stomatitis, altered attention span, abnormal skin and nail formation, microcytic anemia

c. Recommendations/requirements

1) Iron dextran is not routinely added to parenteral solutions, rather if required is provided as a separate infusion

3. Iodine

a. Uses/function: thyroid hormone synthesis

b. Signs/symptoms of deficiency: goiter, hypothyroidism

c. Recommendations/requirements: 50 to 500 mcg/day intravenous

4. Zinc

a. Uses/function: most abundant of all the trace elements; an integral part of many enzymes and enzyme cofactors; is necessary for RNA, DNA, and protein synthesis

b. Signs/symptoms of deficiency: alopecia, scaling, pustular rash, periorbital and nasolabial dermatitis; diarrhea; mental depression/apathy; glucose intolerance; night blindness; impaired taste sensation, wound healing, and T-lymphocyte dysfunction

c. Recommendations/requirements: 2.5 to 4.0 mg/day intravenous; additional 2 mg for acute catabolic state, additional 12 mg/L for small bowel fluid loss, and additional 17.1 mg/kg for stool or ileostomy output

5. Copper

a. Uses/function

1) Essential with iron for normal erythropoiesis

2) Constituent of many oxidative enzymes, such as ceruloplasmin, cytochrome oxidase, monoamine oxidase, and tyrosinase

3) Ceruloplasmin aids the oxidation of ferrous iron in tissue stores to the ferric form to enable it to be transported by transferrin

4) Copper deficiency results in anemia with an iron deficiency picture

b. Signs/symptoms of deficiency: microcytic anemia, leukopenia, neutropenia, skin and hair depigmentation, skeletal demineralization, and hypothermia

c. Recommendations/requirements: 0.5 to 1.5 mg/day intravenous (withhold in jaundiced patients or in those with liver dysfunction)

6. Chromium

a. Uses/function: potentiates insulin reaction with tissue receptors; in its absence, insulin-resistant diabetes and neurologic changes have been noted during PN

b. Signs/symptoms of deficiency: insulin-resistant glucose intolerance, neurologic changes (neuropathy), elevated serum lipids

c. Recommendations/requirements

1) 10 to 15 mcg/day intravenous

2) 20 mcg/day intravenous in the presence of intestinal losses

7. Manganese

a. Uses/function

1) Antioxidant protection and energy metabolism

2) Formation of connective tissue

3) Soluble cofactor in a number of enzymatic reactions

4) Affects carbohydrate synthesis from pyruvate

b. Signs/symptoms of deficiency: extrapyramidal symptoms, bony abnormalities, central nervous system dysfunction, weight loss, transient dermatitis, occasional nausea and vomiting, changes in hair color

c. Recommendations/requirements: 0.15 to 0.80 mg/day intravenous

8. Selenium

a. Uses/function: catalyst for the enzyme glutathione peroxidase, an important antioxidant pathway

b. Signs/symptoms of deficiency: muscle dysfunction (including cardiac muscle changes), myalgias

c. Recommendations/requirements: 100 to 200 mcg/day intravenous

9. Molybdenum

a. Uses/function: cofactor for sulfite oxidase and xanthine oxidase

b. Signs/symptoms of deficiency: headache, night blindness, irritability, lethargy, coma

c. Recommendations/requirements: 150 to 500 mcg/day intravenous

1. Definition: vitamins are organic compounds necessary for normal growth and maintenance of the body but are required only in minute quantities; they cannot be synthesized by the body in sufficient amounts and thus must be provided in the diet

2. Properties/requirements

a. Act as cofactors for the operation of certain enzyme systems

b. The exact vitamin requirements for patients receiving PN are not known

c. Recommendations are typically based on estimations derived from the requirements of normal adults and adjusted for patients who have increased requirements as a result of illness, nutritional depletion, or stress

d. The composition of parenteral multivitamin preparations is based on recommendations established by the AMA Department of Food and Nutrition

3. Classifications

a. Fat soluble: vitamins A, D, E, and K

b. Water soluble: ascorbic acid (vitamin C) and the B complex vitamins: thiamine (B₁), riboflavin (B₂), niacin (B₃), pantothenic acid (B₅), pyridoxine (B₆), biotin (B₇), folic acid (B₉), and cyanocobalamin (B₁₂)

4. Factors that alter the status

a. Malnutrition, specific disease states, and drug therapy may predispose some patients to vitamin deficiencies

b. Continuous parenteral infusion of a multivitamin preparation is physiologically different from oral administration; the gut and liver play important roles in modifying and storing orally ingested vitamins

5. Vitamin A (retinols)

a. Uses/function

1) Essential for the integrity of epithelial surfaces, synthesis of retinal pigments, and protection against infection

2) Fat-soluble and stored in the liver

b. Signs/symptoms of deficiency: night blindness, xerophthalmia, mucosal keratinization

c. Recommendations/requirements: 3,300 International units (1 mg) daily intravenous

6. Vitamin D (calcitriol)

a. Uses/function

1) Promotes intestinal calcium and phosphate absorption

2) Mediates the mobilization of calcium from bone

b. Signs/symptoms of deficiency: bone pain and tenderness, proximal muscle weakness, skeletal deformity, low serum calcium and serum phosphate, elevated alkaline phosphate, tetany caused by hypocalcemia

c. Recommendations/requirements: 200 International units daily intravenous

7. Vitamin E (tocopherol)

a. Uses/function: acts as an antioxidant at the tissue level

b. Signs/symptoms of deficiency: edema, reticulocytosis, decreased erythrocyte survival time, excessive creatinuria, skeletal muscle lesions, increased platelet aggregation

c. Recommendations/requirements

1) 10 International units daily intravenous

2) A portion may come from lipid emulsions and a part from added vitamin

8. Vitamin K (phytonadione)

a. Uses/function: required for the synthesis of clotting factors II, VII, IX, and X

b. Signs/symptoms of deficiency: bleeding, prolonged prothrombin time, hematuria

c. Recommendations/requirements: 150 mcg/day intravenous (evaluate and monitor the use in the presence of anticoagulant therapy)

9. Thiamine (B1)

a. Uses/function

1) An integral part of the cocarboxylase enzyme complex, which is necessary for the metabolism of alpha-keto acids such as pyruvate

2) Cells, such as neurons, that depend exclusively on carbohydrates as an energy substrate need thiamine

b. Signs/symptoms of deficiency: beriberi, peripheral neuropathy, Wernicke’s encephalopathy, decreased or absent deep tendon reflex, muscle tenderness, muscle atrophy, fatigue, decreased attention span

c. Recommendations/requirements: 6 mg/day intravenous

10. Riboflavin (B₂)

a. Uses/function: coenzyme or active prosthetic group of flavoproteins involved with tissue oxidation and respiration

b. Signs/symptoms of deficiency: cheilosis, lip inflammation, oral fissures, seborrhea dermatitis, corneal vascularization, ocular disturbances

c. Recommendations/requirements: 3.6 mg/day intravenous

11. Niacin (B₃)

a. Uses/function: component of coenzymes nicotinamide adenosine dinucleotide (NAD) and NAD phosphate, which are essential for glycolysis, fat synthesis, and energy production

b. Signs/symptoms of deficiency: weakness, pellagra, diarrhea, tongue fissures, mental disorders, anorexia, oral inflammation, irritability

c. Recommendations/requirements: 40 mg/day intravenous

12. Pantothenic acid (B₅)

a. Uses/function: as part of coenzyme A, involved in the release of energy from carbohydrate synthesis of sterols, fatty acids, and steroid hormones

b. Signs/symptoms of deficiency: abdominal pain and cramps, headache, nausea/vomiting, lethargy

c. Recommendations/requirements: 15 mg/day intravenous

13. Pyridoxine (B₆)

a. Uses/function

1) Cofactor for many amino acid-metabolizing systems

2) Affects many neurotransmitters

3) Required for the synthesis of heme proteins

b. Signs/symptoms of deficiency: central nervous system disorders, nasolabial seborrhea, glossitis, hypochromic microcytic anemia

c. Recommendations/requirements: 6 mg/day intravenous

14. Biotin (B₇)

a. Uses/function

1) Essential cofactor for several enzymes

2) Has direct and indirect effects on fatty acid synthesis, carbohydrate metabolism, and protein and nucleic acid synthesis

b. Signs/symptoms of deficiency: skin rash, alopecia, lethargy, depression, paresthesias, anemia, anorexia, nausea, muscle pain

c. Recommendations/requirements

1) 60 mcg/day intravenous

2) 300 mcg/day intravenous for repletion

15. Folic acid (B₉)

a. Uses/function: transfer single carbon units as tetrahydrofolate

b. Signs/symptoms of deficiency: macrocytic anemia, diarrhea, stomatitis, glossitis, malabsorption

c. Recommendations/requirements: 0.4 to 1.0 mg/day intravenous

16. Cyanocobalamin (B₁₂)

a. Uses/function: affects nucleic acid formation

b. Signs/symptoms of deficiency: megaloblastic anemia, glossitis, stomatitis, constipation, neuropathy

c. Recommendations/requirements: 5 mcg/day intravenous

17. Ascorbic acid (vitamin C)

a. Uses/function

1) Affects the growth of fibroblasts, osteoblasts, and odontoblasts

2) Plays a role in hydroxylation of proline and lysine

3) Enhances absorption of iron and inhibits absorption of copper from the gastrointestinal tract

4) Aids formation of active compounds from tetrahydrofolates

b. Signs/symptoms of deficiency: delayed wound healing, scurvy, hemorrhagic petechiae, gingivitis