II. Defintions
-
Nutritional Support Therapy
- Formulated enteral or Parenteral nutrients given to Restore nutritional status
- Enteral Nutrition
- Gastrointestinal Tract delivery of Nutritional Support
-
Parenteral Nutrition
- Intravenous delivery of Nutritional Support
III. Indications
IV. Contraindications
- Severe gastrointestinal dysfunction (refractory Vomiting, ileus or Bowel Obstruction)
- Hemodynamic instability
- Multisystem organ failure
V. Evaluation
VI. Technique: Enteral Nutrition devices
-
Nasogastric Tube
- Indicated in short-term enteral support (e.g. hospitalized patients)
-
Enterostomy Tube
- Indicated in long-term enteral support
-
Gastrostomy Tube
- Gastric feeding is typically preferred for more physiologic intake and larger volumes
-
Jejunostomy Tube (Post-pyloric feeding) Indications
- Aspiration risk
- Severe Esophagitis
- Gastric dysmotility or gastric obstruction
- Recurrent Emesis
- Pancreatitis
VII. Technique: Feeding Protocols
- Bolus Feedings
- Most closely resembles physiologic intake
- Indicated in non-critically ill patients with intact Gag Reflex and normal gastrointestinal function
- Intermittent Feedings
- Delivered over 20-30 minutes in non-critically ill patients unable to tolerate bolus feedings
- Cyclic Feedings
- Delivered over 8 to 16 hours via feeding pump
- Continuous Feedings
- Delivered over 12-24 hours via feeding pump
VIII. Preparations: Polymeric Formulations (Intact or whole macronutrient formulas)
- Polymeric - Standard
- Isotonic, lactose-free, nutritionally complete formulas
- Indicated for normal Gastrointestinal Tract
- Adult: 1-1.2 kcal/ml
- Boost, Ensure, Isocal, Jevity 1.2, Nutren 1.0, Osmolite
- Child: 1 kcal/ml or 30 kcal/oz
- Boost kid essentials, Pediasure, Nutren Junior
- Polymeric - High Calorie
- Concentrated formulas with significantly higher calories per ml (typically by increasing fat concentration)
- Indicated for fluid restriction (CHF, SIADH) or high calorie requirement (e.g. Trauma)
- Adult: 2 kcal/ml
- Deliver 2.0, Novasource 2.0, Nutren 2.0, Twocal HN
- Child: 1.5 kcal/ml or 45 kcal/oz
- Boost kid essentials 1.5, Resource Just for Kids 1.5
- Polymeric - High Protein
- Indicated for hypercatabolic state or high Protein requirement (e.g. Wound Healing)
- Adult: 1-1.5 kcal/ml with Protein comprising 18-25% of total calories
- Boost high Protein, Ensure plus HN, Isocal HN, Isosource HN, Osolite 1.2 CAL, Replete, Sustacal HC
- Polymeric - With fiber
- Isotonic, typically soy-based fiber of both soluble and insoluble types with 4-22 grams fiber per Liter
- Indicated for prevention of Diarrhea in the short-term, and Constipation in the long-term
- Adult: Ensure with fiber, Fibersource HN, Jevity, Ultracal
- Child: Nutren Junior with fiber, Pediasure with fiber
- Blenderized
- Pureed natural foods
- Indicated for longterm enteral support and intact gastrointestinal function
IX. Preparations: Elemental Formulations
- Oligomeric
- Elemental formula, Proteins with short peptides and free Amino Acids, higher osmolarity and lactose-free
- Provide 1-1.5 kcals/ml
- Indicated for malabsorption syndromes and pancreatic insufficiency
- Disadvantages: Expensive, may worsen Diarrhea
- Adults: Criticare HN, Peptamen, Perative, Subdue, Tolarex, Vital HN, Vivonex TEN, Vivonex Plus
- Child: Peptamen Junior, Vivonex Pediatric
- Modular Formulation
- Indicated for a specific nutrient deficiency or as a component in a multi-formulation plan
- Protein formulations: Beneprotein instant Protein powder, Promod
- Carbohydrate formulations: Moducal, Polycose
- Fat formulations: MCT Oil, Microlipid
- Fiber formulations: Benefiber
X. Preparations: Disease Specific Formulations
- Diabetic Formulation
- Lower Carbohydrate, higher monounsaturated fat, and higher fiber; 1 kcal/ml
- Preparations: Choice DM, Diabetisource, Glucerna, Glytrol
- Immunomodulating Formulation
- Higher Protein, with increased Arginine, Glutamine, Omega-3 Fatty Acids and other components
- Provides components thought to improve immune response
- Indicated in ICU patients with major Trauma, burns, or the critically ill on Mechanical Ventilation
- Deliver 1-1.5 kcal/ml
- Preparations: Alitraq, Crucial, Impact
- Pulmonary Formulation
- Low Carbohydrate, high fat, no fiber formulations with 1.5 kcal/ml
- Some contain Omega-3 Fatty Acids and antioxidants which may be considered in Acute Lung Injury or ARDS
- Indicated for COPD, Mechanical Ventilation weaning (formulated to reduce carbon dioxide production)
- Preparations: Nutren, Nutrivent, Oxepa, Pulmocare
- Low Carbohydrate, high fat, no fiber formulations with 1.5 kcal/ml
- Renal Formulation
XI. Labs
- Baseline
- Complete Blood Count
- Glucose
- Electrolytes including Magnesium, phosphate, Calcium
- Renal Function tests
- Liver Function Tests including albumin
- Serum Iron
- Vitamin B12
- Vitamin D
- Zinc
- Copper
- Serum Folate
- INR
- Monitoring: Frequency based on clinical status
- Complete Blood Count
- Glucose (several times daily)
- Electrolytes including Magnesium, phosphate, Calcium
- Renal Function tests
- Liver Function Tests including albumin
- Expect 2-3 fold over baseline with 10-14 days TPN
- Monitoring: periodic recheck when on longterm Enteral Nutrition
- Vitamin B12
- Vitamin D
- Zinc
- Copper
- Serum Folate
- Other monitoring
- Gastric residuals every 4 to 6 hours when gastric feeding
- Monitor intake and output
XII. Complications
- See Refeeding Syndrome
-
Aspiration Pneumonia (up to 44% of cases)
- Elevate head of bed to 30 degrees
- Measure gastric residuals periodically and adjust instillation volumes as needed
- Inflate endotracheal cuff if intubated
- Consider postpyloric feeding (Nasoduodenal tube or Jejunostomy)
-
Diarrhea (up to 65% of cases)
- Management
- Evaluate for and treat underlying cause first
- Reduce rate and titrate more slowly
- Add fiber to formulation
- Consider antidiarrheal medication
- Causes
- Sorbitol containing elixirs
- Antibiotics with secondary Clostridium difficile
- Low fiber content
- High fat content
- Bacterial contamination of delivery device
- Hyperosmolar formulation
- Delivery rate too high
- Management
-
Feeding Tube related complications
- See Feeding Tube
- Fluid, Electrolyte, and metabolic abnormalities
- Hyperglycemia
- Vitamin K Deficiency
- Trace element deficiency (zinc, copper)
- Vitamin B12 Deficiency
- Iron Deficiency
- Hypertonic Dehydration (calorie dense formulations with inadequate fluid intake)
XIII. References
- Bankhead (2009) JPEN J Parenter Enteral Nutr 33(2): 122-67 [PubMed]
- Bristrian (2006) Crit Care Med 34(5): 1525-31 [PubMed]
- Chen (2009) Nutr Clin Pract 24(3): 344-55 [PubMed]
- Koretz (2009) Nutr Clin Pract 24(3): 316-324 [PubMed]
- Kulick (2011) Am Fam Physician 83(2): 173-83 [PubMed]
- Lesser (2021) Am Fam Physician 104(6): 580-8 [PubMed]