Nutrition Support in the Hospital Patient

David Armstrong November 2, 2005

What is Nutritional Support

The provision of nutrients orally, enterally, or parenterally with therapeutic intent. This includes, but is not limited to, provision of total enteral or parenteral nutrition support, and provision of therapeutic nutirents to maintain and /or restore optimal nutrition status and health.
ASPEN, 2002

Who Should Get Nutritional Support?

Patients who: Cannot meet nutrient requirements Have documented inadequate oral intake Have unpredictable return of GI function Need a prolonged period of NPO/bowel rest

Indications for Supplementary Nutrition Support (SNS)

Nutrition support As primary therapy for a disease As an adjunct to primary therapy
To treat malnutrition To avoid development of malnutrition from low energy & nutrient intake or increased needs

Determining Requirements
Harris-Benedict Equation Females: 655 + (9.6 x W) + (1.8 x H) - (4.7 x A) Males: 65 + (13.7 x W) + (5 x H) - (6.8 x A) Adjust for activity, stress, illness, injury

Components of Energy Expenditure

120% 100% 80% 60% 40% 20% 0%

EEPA ~ 15-30% TEF ~ 10% REE ~ 60-75%

EEPA Energy Expenditure from Physical Activity TEF Thermogenic Effect of Feeding REE Resting Energy Expenditure

Energy Expenditure
Indirect calorimetry should be the preferred standard for measurement of oxygen consumption in severly injured patients.
Epstein et al, Critical Care Medicine 2000

Enteral Nutrition
Use of formulae as oral supplements or meal replacements when oral intake is inadequate or contraindicated Delivery of nutrients via a tube into the GI tract

Benefits of Enteral Nutrition

Kotler, D.P. Am J Physiol 238:G219-G227, 1980. Photomicrographs by Gary Levine, M.D.

Maintains gut mucosal physiology Preserves gut barrier function Promotes peristalsis May modulate immune response Inexpensive compared with Parenteral Nutrition

Fed Orally

Fed by TPN

Appropriate Candidates for Tube Feeding

Functional GI tract Oral intake is inadequate:
to restore nutritional status to maintain nutritional status

Conditions that often Require Enteral Nutrition

Impaired Nutrient Digestion Inability to Consume Adequate Oral Nutrition Impaired Digestion, Absorption, Metabolism Severe Wasting or Growth Retardation

Is EN Feasible? Guiding Principles

A clinical assessment of intestinal function is required to ensure safety EN should be prescribed only if safety and a low complication rate can be ensured A good determinant of safe tolerance of EN is a GI output of less than 600 ml/24 hr (e.g., effluent from a nasogastric tube, ostomy, fistula or rectal tube)

Enteral Access Selection

Anticipated length of therapy Degree of aspiration risk or tube displacement Presence or absence of normal digestion Planned surgical/endoscopic intervention Administration and infusion schedule Patient comfort/quality of life

Nasogastric Tube Feedings

Short term < 30 days Intact gag reflex Normal gastric function Low risk of aspiration Easy tube placement Surgery not required Easy to check gastric residuals Accomodates bolus or intermittent infusions

Nasoenteric Tube Feeding

Transpyloric Compromised placement may be gastric function difficult Early enteral feeding Frequent May decrease dislodgement aspiration risk Surgery not required Tube malposition common

Gastrostomy Tube -long term > 30 days -bolus, intermittent or continuous feedings -meal times

PEG G/J Tubes

Allows gastric decompression & simultaneous JT feeding

Enteral Formula Selection

Gastrointestinal function
digestive and absorptive capacity

Physical characteristics of the formula

osmolality lactose content fiber content caloric density metabolic needs/organ dysfunction fluid and electrolytes

Categories of Enteral Formula

Standard Hydrolyzed/Pre-Digested Elemental Disease Specific Rehydration Modular

Standard Formula
Normal or minimally impaired digestion Requires absorption Intact protein, meal replacement 1, 1.2, 1.5, 2 cal/ml May contain fiber

Hydrolyzed Formula
GI compromise Improved digestion Protein typically small peptides

Elemental Formula
Limited GI function Minimal residue Protein is free amino acids Minimal fat

Disease Specific Formula

Designed for specific organ dysfunction or metabolic abnormality May not be nutritionally complete Hepatic, Renal, Pulmonary, Diabetes, Immuno, Trauma Evaluate carefully for efficacy and benefit

Tube Feeding Administration

Bolus Gravity Pump

Infusion Schedule
Meal Time Intermittent Continuous Cyclic - Overnight
No magic to 12 hours

Complications of Enteral Nutrition

Access Problems Administration Problems Gastrointestinal Metabolic Psychologic

Parenteral Nutrition: Indications for use

GI tract is not functioning well enough to meet nutritional needs of patient so nutrients put in bloodstream intravenously examples: Small bowel resection Bowel obstruction (small or large) Large output fistula
below enteral feeding site

Parenteral Nutrition - Access Sites

Central access: surgical / radiological placement of catheter in large, high blood flow vein TPN (total parenteral solution) PICC line: catheter inserted in vein in arm; solution taken to high blood flow vein TPN Peripheral access (also, midline): catheter tip placed in vein in arm. Requires more dilute peripheral parenteral solution PPN

Solutions: CHO = Dextrose

Supplied as dextrose: 10% to 35% 10%= 100 gm/L, 25% = 250 gm/L Dextrose provides 3.4 Kcal/gm 1 liter of 10% soln = (100gm x 3.4Kcal/gm) = 340 Kcal PPN Peripheral Parenteral Nutrition is put into small (peripheral) vein so cannot use more than D10

Solutions: Protein (2.5% A/A) + D15 @ 60cc/hr

Supplied as A/A essential & nonessential: Choices:
2.5, 4.25, 5% solutions 2.5% = 25 gm/L; 4.25% soln = 42.5 gm/L

Protein provides 4 Kcal/gm

often not be included in total Kcal

60 cc x 24 = 1.44 L x 25 g/L = 36 gms in 24 hrs & 144 kcal of prot 1.44 L x 150 gm/L = 216 g dextrose x 3.4 kcal/gm = 734 kcal in 24 hrs

Parenteral Nutrition Solutions: Lipids

Supplied as aqueous suspension of soybean or safflower oil with egg yolk phospholipids as the emulsifier. Glycerol is added to suspension. 2 levels of emulsions: 10% solution: 1.1 kcal/mL 20% solution: 2.0 kcal/mL

D15 with 2.5% aa @ 60cc/hr and 10% IL at 11 cc/hr

11 cc/hr x 24 hr = 264 cc x 1.0 kcal/cc = 264 kcal/day Total kcal: 1142 Kcal from fat: 264 (23%) Kcal from CHO: 734 (64%) Kcal from prot: 144 (13%)

Parenteral Nutrition Solutions

Guidelines for amounts of each to provide: Protein: 15 - 20% of kcal Lipids: ~30% of kcal CHO: 50-65% of kcal Electrolytes, vitamins, trace elements: lower than DRI Fluid: 1.5 - 2.5 liters total

Kcal: N ration: 125 kcal:1 gm N

Parenteral Nutrition Solutions

Prepared aseptically & delivered 2 ways: 3 in 1 solution: pro,fat,CHO in one bag and 1 pump is used to infuse solution 3 in 2 solutions: 2 bag method: protein & CHO in 1 bag & lipid solution in glass bottle; each is hooked up to pump; solutions enter vein together Given continuously or cyclically (8-12 hrs/day) Insulin may be added to solution

Parenteral Nutrition Solutions: Selected Complications

Mechanical: thrombophlebitis Infection and sepsis of catheter site Gastrointestinal: villous atrophy Metabolic: hyperlipidemia, trace mineral deficiencies, electrolyte imbalance Liver disease Refeeding syndrome

Transitional Feeding
A process of moving from one type of feeding to another with multiple feeding methods used simultaneously Examples: parenteral feeding to enteral feeding parenteral feeding to oral feeding enteral feeding to oral feeding

Transitional Feeding parenteral to enteral

1. Introduce enteral feeding 30 cc/hr while giving parenteral 2. If tolerated, gradually parenteral while increasing enteral 3. Once patient can tolerate 75% of needs enterally, d/c parenteral Process is called a stepwise decrease

Transitional Feeding parenteral to oral and enteral to oral

Use step-wise decrease method; wait until patient accepting 75% oral and then decrease parenteral or enteral method But may need to: Offer oral during the day & cycle other from 6pm -6am in order to provide motivation & reestablish hunger patterns Some children & adults may continue on oral during the day and enteral at night

Nutrition Support
Most effective when provided by team: RD, RN, Pharm D in conjunction with MD Regular monitoring of electrolytes, LFTs, CBC & nutritional markers Use appropriately to maximise cost-benefit
Specialised supplements are more expensive / benefit often unproven

Know patients wishes living will or advance directive