Implementing Enteral Implementing Enteral Nutrition: Formula Nutrition: Formula

Selection and Selection and AdministrationAdministration

Objectives

• To describe the categories of enteral formulas• To explain how to choose the appropriate category of

enteral formula for each patient’s disease state• To describe the various methods for delivering

enteral nutrition and how to choose the most appropriate formula for each situation

Enteral Formulas: Categories

• Polymeric formulas– Commercial– Blenderized

• Oligomeric formulas • Disease-specific formulas • Modular formulas (concentrated protein and

carbohydrate preparations)

Polymeric Formulas

Contain intact macronutrients and require digestion: Intact proteins Polysaccharides Disaccharides Polyunsaturated fatty acids (PUFA) Medium-chain triglycerides (MCT)

Polymeric Formulas:Benefits of Commercial Formulas Commercial Formulas Blenderized Formulas

Uniform contentsSterile

Low viscosityLactose freeDefined caloric density

Daily nutrient variabilityNon-sterile; high bacterial content and other pathogensHigh viscosityDoes not provide adequate caloric density

Gallagher-Allred. Nutrition Supp Svc 1983; Tanchoco CC, et al. Respirology 2001;6:43-50Sullivan MM, et al. J Hosp Infect 2001;49:268-273

Commercial Polymeric Formulas: Selection

Features• Protein, caloric density, and osmolality vary• With or without added fiber• Most are lactose- and gluten-free• Nutritionally complete in sufficient quantities

Patient must have:• Functional GI tract• Normal digestion• Normal absorption

Oligomeric Formula Categories

Hydrolyzed macronutrients facilitate digestion and absorption

ComponentsAmino acids

– Glutamine– Arginine

PeptidesMonosaccharides Disaccharides

Also called “elemental,” “semi-elemental,” “hydrolyzed”, or “chemically defined” formula.

In: Rombeau JL, Rolandelli RH, eds. Clinical Nutrition: Enteral and Tube Feeding. 3rd ed. WB Saunders Company; 1997

Glucose polymers

Polyunsaturated fatty acids

Medium-chain triglycerides

Vitamins and minerals

Oligomeric Formulas: Selection

Indications for Use:

• Inflammatory bowel disease• Pancreatic insufficiency• Malabsorption • Short bowel syndrome• Radiation enteritis• Early enteral feeding • Intolerance to polymeric formula

Enteral Formula Selection: Disease-Specific Formulas

• Pulmonary disease• Glucose intolerance• Cancer-induced weight loss• Hepatic insufficiency • Critical care• Renal failure• HIV+/AIDS

Cabre E, Gassull MA. Nutrition 1992;8:1-9.

Disease-Specific Formula Selection:Pulmonary Disease (Chronic)

Pulmonary disease with CO2 retention

• Decreased carbohydrate content• Increased fat content• High caloric density• Intact proteins• Fiber supplement

Brown RO et al. Clin Phar 1984;3:152-161; Askanazi J et al. Anesthesiology 1981;54:373-377Deitel M et al. J Am Coll Nut 1983;2:25-32

Disease-Specific Formula Selection:Glucose IntoleranceGlucose Intolerance• Diabetes mellitus

– Type I – Type II

• Hyperglycemia associated with: – Pancreatic disease – Drug and chemical-induced – Insulin receptor abnormalities

– Hormonal alterations– Genetic syndromes– Metabolic stress

Cabre E, Gassull MA. Nutrition 1992;8:1-9

Disease-Specific Formula Selection:Glucose Intolerance

Recommendations• Low carbohydrate content

– Monosaccharides (fructose)– Glucose polymers

• Increased monounsaturated fat (MUFA)• Added fiber

Franz MJ, et al. Diabetes Care 1994;17:490-518; J Am Diet Assoc 1994;94:504-506Diabetes Care 1997;20:514-517

Disease-Specific Formula Selection:Cancer-Induced Weight LossCancer-Induced Weight Loss• Complex metabolic syndrome - anorexia, fatigue,

early satiety• Significant weight loss & muscle wasting• Etiology is multifactorial

– Pro-inflammatory cytokines – Acute phase response– Abnormal metabolism– Proteolysis inducing factor (PIF)

• Cannot correct by additional calories alone

Negative Prognosis

&QOL

Disease-Specific Formula Selection:Cancer-Induced Weight LossRecommendations

• High protein and Zn to build muscle • Low fat to avoid early satiety• Low in sucrose for better patient acceptance• High in fermentable fibers• Eicosapentaenoic acid (EPA) • Antioxidants (vitamins A, C, E and Se)• Folate and iron for anemia

Disease-Specific Formula Selection:Hepatic Disease

Hepatic Insufficiency• Altered protein metabolism and protein loss• Altered carbohydrate metabolism

– glucose intolerance– low hepatic glycogen stores

• Malabsorption of fat and fat-soluble vitamins• Inability to elongate or desaturate essential fatty acids• Vitamin and mineral deficiencies (e.g., B-complex and Zn)• Impaired urea synthesis with hyperammonemia and hepatic

encephalopathy• Fluid and sodium retention• Reduced appetite/oral intake and taste impairment

Disease-Specific Formula Selection:Hepatic Disease

Recommendations

• High caloric density with low sodium content• Moderately high calorie:nitrogen ratio• High in branched chain AAs and low in aromatic AAs• Non-digestible soluble fiber • Long-chain fatty acids and supplemental MCT• Supplemented with fat soluble vitamins, Zn, folic acid and B

complex vitamins• Low copper, iron, manganese content

Disease-Specific Formula Selection:Critical Care

Types of Injury• Elective surgery• Minor trauma• Burn• Pressure ulcer

Patient Conditions• Sepsis• Inflammatory

Disease-Specific Formula Selection:Critical CareNutrient Choices• Hydrolyzed or intact proteins• Glutamine• Arginine• Taurine, Carnitine• Eicosapentaenoic acid (EPA), Gamma-linolenic Acid (GLA)• Antioxidants

Poullain et al. JPEN 1989;13:382-386; Lacey JM et al. Nutr Rev 1990;48:297-309 Barbul A et al. Surgery 1990;108:331-337

Disease-Specific Formula Selection:Critical Care (Mechanical Ventilation)Lung Injury / SIRS / ARDS

• Eicosapentaenoic acid (EPA) • Gamma-linolenic Acid (GLA)• Antioxidants• High caloric density• No arginine supplementation

Gadek J. Chest 1998;114:277S; Gadek J. Crit Care Med 1999;27:1409-1420; Pacht ER, et al. Crit Care Med 2003;31:491-500

Disease-Specific Formula Selection:Critical CareArginine (a double-edged sword)

• Conditionally essential nutrient that enhances wound healing

• Supports immune system and is associated with reduced infectious complications

“Giving arginine to a septic patient is like putting gasoline on an already burning fire.”

- B. Mizock, Medical Intensive Care Unit, Cook County Hospital, Chicago, IL

Disease-Specific Formula Selection:Renal Disease

Acute or Chronic Renal Disease

• Increased BUN and creatinine• Increase in serum electrolytes:

– Na – K – PO4

– Mg

Kopple JD. In: Shils ME et al eds. Modern Nutrition in Health and Disease. 8th ed. Philadelphia: Lea & Febiger; 1994:1102-1134; Blumenkranz MJ et al. Kidney Int 1982;21:849-851

Disease-Specific Formula Selection:Renal DiseaseRecommendations

• Protein content – Predialysis: 30 g/L – Dialysis: 70 g/L

• Low electrolyte content• High caloric density

Monson P, et al. J Renal Nutr 1994;4:58-77 ASPEN Board of Directors. JPEN 2002;26 Suppl 1

Disease-Specific Formula Selection:Advanced AIDS (with weight loss)Advanced AIDS

• Weight loss > 5% below normal• CD4 < 400• Serum albumin < 3.0 g/dL• Opportunistic infection• Diarrhea• Impaired immune function

Raiten DJ. Nutrition and HIV Infection. Department of Health and Human Services, Washington D.C.Grunfeld C et al. Sem Gastro Dis 1991; Kotler DP et al. Am J Clin Nutr 1985

Disease-Specific Formula Selection:Advanced AIDS (with weight loss)

Recommendations

• Increased protein• Low fat for improved tolerance• Added fiber• EPA to down regulate metabolic changes associated

with cachexia• Increased levels of antioxidants (beta-carotene, vitamin

E, C) and B vitamins (B6, B12)

Baum MK, et al. Ann N Y Acad Sci 1992;669:165-174Raiten DJ. Nutrition and HIV Infection. Dept. of Health and Human Services , Washington D.C.

Enteral Formula: Selection

• Metabolic requirements• Patient condition or status• Pre-existing conditions• GI function

Enteral Formula: Selection

• The physician should know the formula’s nutrient profile to meet specific patient needs

• Understand the clinical evidence supporting specific formula use

• Data obtained exclusively from animal models may or may not apply to the clinical setting

Enteral Formula: Oral AdministrationOral Supplementation

• Indicated especially for patients with malnutrition or at risk for weight loss

• When given between meals, does not reduce intake of other foods

• Frequently stimulates increased intake of other foods

• Thickened oral supplements are useful for patients with dysphagia

Benefits of Oral Supplements

Improvement in Oral Intake

Prop

ortio

nal I

ncre

ase

Delmi M et al. Lancet 1990;335:1013-1016

0

50

100

150

200

250

Daily Energy(kcal)

Daily Protein (g) Daily Calcium(mg)

Without Supplement

With Supplement

Enteral Formula: Tube Feeding

Type:• Intermittent • Continuous:

– 24 hours / day – During part of the day or at night

Infusion Method:• Gravity• Infusion pump

Gottschlich MN, Shronts EP, et al. Defined formula diets. In: Rombeau JL, Rolandelli, eds. Clinical Nutrition: Enteral and Tube Feeding. W B Saunders; 1997; Giocon JO et al. JPEN 1992;16:525-528

Enteral Formula: Administration

Enteral Feeding

Intermittent

• Resembles normal feeding and digestion patterns• 250-500 mL of formula• Administered over 30-60 minutes• 5-8 times daily

Enteral Formula: Administration

Continuous

Plan 1

Beginning: Day 1: 1000 mL over 24 hoursProgress: Day 2: 1500 mL over 24 hours

Day 3: final volume according to needsPlan 2

Beginning: 25 mL/h (first 12 hours)Progress: 50 mL/h for next 12 hours

rate according to needs

Enteral Formula: Administration

Infusion PumpIndications

Small intestine feeding

Fluid restrictions

Risk of aspiration

Need for precise flow rate

Nocturnal feeding

Infants and small children

Gravity InfusionIndications

Suitable for intermittent feeding

Ambulatory patients

Gastric feeding

Enteral Formula: Administration

Summary

• Intermittent feeding • Continuous feeding

ASPEN Board of Directors. JPEN 2002;26 Suppl 1: 34SA.

Summary

• Described the categories of enteral formulas • Explained how to select appropriate formulas • Described the methods of enteral nutrition

administration