Enteral Nutrition

Nutritional Support Therapy
1. Formulated enteral or Parenteral nutrients given to Restore nutritional status
Enteral Nutrition
1. Gastrointestinal Tract delivery of Nutritional Support
Parenteral Nutrition
1. Intravenous delivery of Nutritional Support

Severe gastrointestinal dysfunction (refractory Vomiting, ileus or Bowel Obstruction)
Hemodynamic instability
Multisystem organ failure

Nasogastric Tube
1. Indicated in short-term enteral support (e.g. hospitalized patients)
Enterostomy Tube
1. Indicated in long-term enteral support
2. Gastrostomy Tube
  1. Gastric feeding is typically preferred for more physiologic intake and larger volumes
3. Jejunostomy Tube (Post-pyloric feeding) Indications
  1. Aspiration risk
  2. Severe Esophagitis
  3. Gastric dysmotility or gastric obstruction
  4. Recurrent Emesis
  5. Pancreatitis

Bolus Feedings
1. Most closely resembles physiologic intake
2. Indicated in non-critically ill patients with intact Gag Reflex and normal gastrointestinal function
Intermittent Feedings
1. Delivered over 20-30 minutes in non-critically ill patients unable to tolerate bolus feedings
Cyclic Feedings
1. Delivered over 8 to 16 hours via feeding pump
Continuous Feedings
1. Delivered over 12-24 hours via feeding pump

Polymeric - Standard
1. Isotonic, lactose-free, nutritionally complete formulas
2. Indicated for normal Gastrointestinal Tract
3. Adult: 1-1.2 kcal/ml
  1. Boost, Ensure, Isocal, Jevity 1.2, Nutren 1.0, Osmolite
4. Child: 1 kcal/ml or 30 kcal/oz
  1. Boost kid essentials, Pediasure, Nutren Junior
Polymeric - High Calorie
1. Concentrated formulas with significantly higher calories per ml (typically by increasing fat concentration)
2. Indicated for fluid restriction (CHF, SIADH) or high calorie requirement (e.g. Trauma)
3. Adult: 2 kcal/ml
  1. Deliver 2.0, Novasource 2.0, Nutren 2.0, Twocal HN
4. Child: 1.5 kcal/ml or 45 kcal/oz
  1. Boost kid essentials 1.5, Resource Just for Kids 1.5
Polymeric - High Protein
1. Indicated for hypercatabolic state or high Protein requirement (e.g. Wound Healing)
2. Adult: 1-1.5 kcal/ml with Protein comprising 18-25% of total calories
  1. Boost high Protein, Ensure plus HN, Isocal HN, Isosource HN, Osolite 1.2 CAL, Replete, Sustacal HC
Polymeric - With fiber
1. Isotonic, typically soy-based fiber of both soluble and insoluble types with 4-22 grams fiber per Liter
2. Indicated for prevention of Diarrhea in the short-term, and Constipation in the long-term
3. Adult: Ensure with fiber, Fibersource HN, Jevity, Ultracal
4. Child: Nutren Junior with fiber, Pediasure with fiber
Blenderized
1. Pureed natural foods
2. Indicated for longterm enteral support and intact gastrointestinal function

Diabetic Formulation
1. Lower Carbohydrate, higher monounsaturated fat, and higher fiber; 1 kcal/ml
2. Preparations: Choice DM, Diabetisource, Glucerna, Glytrol
Immunomodulating Formulation
1. Higher Protein, with increased Arginine, Glutamine, Omega-3 Fatty Acids and other components
2. Provides components thought to improve immune response
3. Indicated in ICU patients with major Trauma, burns, or the critically ill on Mechanical Ventilation
4. Deliver 1-1.5 kcal/ml
5. Preparations: Alitraq, Crucial, Impact
Pulmonary Formulation
1. Low Carbohydrate, high fat, no fiber formulations with 1.5 kcal/ml
  1. Some contain Omega-3 Fatty Acids and antioxidants which may be considered in Acute Lung Injury or ARDS
2. Indicated for COPD, Mechanical Ventilation weaning (formulated to reduce carbon dioxide production)
3. Preparations: Nutren, Nutrivent, Oxepa, Pulmocare
Renal Formulation
1. Formulations with reduced Potassium, Phosphorus and Magnesium; available in low and high Protein formulations
2. High Protein formulation (for renal replacement therapy): Magnacal Renal, Nepro
3. Low Protein formulation (if not ion Dialysis): Novasource Renal, Renalcal, Suplena

Baseline
1. Complete Blood Count
2. Glucose
3. Electrolytes including Magnesium, phosphate, Calcium
4. Renal Function tests
5. Liver Function Tests including albumin
6. Serum Iron
7. Vitamin B12
8. Vitamin D
9. Zinc
10. Copper
11. Serum Folate
12. INR
Monitoring: Frequency based on clinical status
1. Complete Blood Count
2. Glucose (several times daily)
3. Electrolytes including Magnesium, phosphate, Calcium
4. Renal Function tests
5. Liver Function Tests including albumin
  1. Expect 2-3 fold over baseline with 10-14 days TPN
Monitoring: periodic recheck when on longterm Enteral Nutrition
1. Vitamin B12
2. Vitamin D
3. Zinc
4. Copper
5. Serum Folate
Other monitoring
1. Gastric residuals every 4 to 6 hours when gastric feeding
2. Monitor intake and output

See Refeeding Syndrome
Aspiration Pneumonia (up to 44% of cases)
1. Elevate head of bed to 30 degrees
2. Measure gastric residuals periodically and adjust instillation volumes as needed
3. Inflate endotracheal cuff if intubated
4. Consider postpyloric feeding (Nasoduodenal tube or Jejunostomy)
Diarrhea (up to 65% of cases)
1. Management
  1. Evaluate for and treat underlying cause first
  2. Reduce rate and titrate more slowly
  3. Add fiber to formulation
  4. Consider antidiarrheal medication
2. Causes
  1. Sorbitol containing elixirs
  2. Antibiotics with secondary Clostridium difficile
  3. Low fiber content
  4. High fat content
  5. Bacterial contamination of delivery device
  6. Hyperosmolar formulation
  7. Delivery rate too high
Feeding Tube related complications
1. See Feeding Tube
Fluid, Electrolyte, and metabolic abnormalities
1. Hyperglycemia
2. Vitamin K Deficiency
3. Trace element deficiency (zinc, copper)
4. Vitamin B12 Deficiency
5. Iron Deficiency
6. Hypertonic Dehydration (calorie dense formulations with inadequate fluid intake)