Specialized nutrition support

Last updated: November 16, 2022

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Specialized nutrition support comprises the administration of enteral nutrition (bypassing the oropharynx) and/or parenteral nutrition (bypassing the GI tract). Specialized nutrition support is primarily indicated in patients with malnutrition and those at high nutritional risk. Enteral nutrition is preferred over parenteral nutrition unless contraindications to enteral nutrition are present (e.g., mechanical bowel obstruction). Nutrition support is associated with various complications such as injury during feeding tube placement, IV catheter-related infection, and metabolic complications. There is a higher risk of metabolic complications with parenteral nutrition than with enteral nutrition.

General principles [1][2]

  • Consult a nutritionist if available. [3]
  • Consider specialized nutrition support in:
    • Hospitalized patients who are both: [2]
      • At high nutritional risk or diagnosed with malnutrition
      • Unable to maintain nutritional status with oral intake
    • Critically ill patients unable to maintain oral intake [4]
  • Specialized nutrition support is usually not indicated in well-nourished adults who are both: [3]
    • At low nutritional risk
    • Expected to resume oral intake within 5–7 days
  • Use clinical judgment and follow local protocols.

Nutritional risk assessment [2]

Common causes of malnutrition in adults [5]

Conditions that may lead to malnutrition include:

Considerations for enteral vs. parenteral nutrition [3][7][8]

Enteral feeding has not been shown to increase survival or improve quality of life in patients with dementia. [3]

The following principle applies to most situations: oral before enteral, enteral before parenteral!

First choice for most patients with indications for specialized nutrition support


Enteral nutrition is the administration of nutrients via a feeding tube placed directly into the stomach, duodenum, or jejunum.

Routes [2]

Nasal or oral access

  • Gastric feeding: preferred initial route
  • Postpyloric feeding, e.g., nasojejunal tube, nasoduodenal tube

Percutaneous access

May be performed endoscopically, surgically, or fluoroscopically

  • Indication: nutrition support is anticipated for ∼ > 4 weeks
  • Types
    • Gastrostomy tube (e.g., inserted via percutaneous endoscopic gastrostomy): a feeding tube that is inserted into the stomach through a small incision in the abdominal wall
    • Jejunostomy tube

Contraindications [7][9]

Absolute contraindications for enteral nutrition include mechanical bowel obstruction and severe bowel ischemia. [1][2]

Aspiration prevention [3][9][10]

  • Ensure adequate tube type and placement.
  • Consider postpyloric feeding if patients experience adverse effects (e.g., recurrent emesis, gastroparesis).
  • Ensure correct patient positioning: Elevate the head of the bed to > 30°.
  • Consider prokinetic agents to promote gastric emptying.

Tube feeding regimens [9]

  • Continuous feeding
    • The typical initial infusion rate is 50 mL/hour.
    • Increase the rate of infusion by 25 mL/hour every 4–8 hours until the target rate is reached.
  • Bolus feeding (gastric feeding only)
    • 200–400 mL of formula multiple times per day
    • Hold if there is residual tube feed formula in the gastric body 4 hours after the previous bolus.

Composition of enteral feeding solutions [3][9][11]

Solution compositions vary based on individual patient needs and should be selected in consultation with a nutritionist.

Enteral nutrition-specific complications [3][7][9]

Nutrition related

Access related

Definition [9]

  • Parenteral nutrition: the intravenous delivery of nutrition, bypassing the GI tract
  • Total parenteral nutrition (TPN): the intravenous provision of all nutritional requirements
  • Supplemental parenteral nutrition: the intravenous provision of nutrients to augment oral intake and meet nutritional goals

Indications [8]

Enteral nutrition is either:

Routes [3][8]

Standard concentrations of total parenteral nutrition formulas (typically > 1800 mOsm/L) are caustic to veins and therefore better tolerated with central venous administration. [3]

Contraindications [3]

Infusion regimens [15]

Composition of parenteral feeding solutions [9]

Parenteral nutrition-specific complications [9]

Metabolic complications are more common with parenteral nutrition than with enteral nutrition!

  1. Carter B, Karpen S. Intestinal Failure-Associated Liver Disease: Management and Treatment Strategies Past, Present, and Future. Semin Liver Dis. 2007; 27 (3): p.251-258. doi: 10.1055/s-2007-985070 . | Open in Read by QxMD
  2. McClave SA, DiBaise JK, Mullin GE, Martindale RG. ACG Clinical Guideline: Nutrition Therapy in the Adult Hospitalized Patient. Am J Gastroenterol. 2016; 111 (3): p.315-334. doi: 10.1038/ajg.2016.28 . | Open in Read by QxMD
  3. Pearce CB. Enteral feeding. Nasogastric, nasojejunal, percutaneous endoscopic gastrostomy, or jejunostomy: its indications and limitations. Postgrad Med J. 2002; 78 (918): p.198-204. doi: 10.1136/pmj.78.918.198 . | Open in Read by QxMD
  4. Jameson JL, Fauci AS, Kasper DL, Hauser SL, Longo DL, Loscalzo J. Harrison's Principles of Internal Medicine, Twentieth Edition (Vol.1 & Vol.2). McGraw-Hill Education / Medical ; 2018
  5. Bechtold ML, Brown PM, Escuro A, et al. When is enteral nutrition indicated?. J Parenter Enteral Nutr. 2022 . doi: 10.1002/jpen.2364 . | Open in Read by QxMD
  6. Kulick D, Deen D. Specialized Nutrition Support. Am Fam Physician. 2011; Volume 83 (Number 2).
  7. Laroia AT, Donnelly EF, Henry TS, et al. ACR Appropriateness Criteria® Intensive Care Unit Patients. J Am Coll Radiol. 2021; 18 (5): p.S62-S72. doi: 10.1016/j.jacr.2021.01.017 . | Open in Read by QxMD
  8. Reber E, Messerli M, Stanga Z, Mühlebach S. Pharmaceutical Aspects of Artificial Nutrition. J Clin Med. 2019; 8 (11): p.2017. doi: 10.3390/jcm8112017 . | Open in Read by QxMD
  9. Pingleton SK. Enteral nutrition in patients with respiratory disease. European Respiratory Journal. 1996; 9 (2): p.364-370. doi: 10.1183/09031936.96.09020364 . | Open in Read by QxMD
  10. Kogo M, Nagata K, Morimoto T, et al. Enteral Nutrition Is a Risk Factor for Airway Complications in Subjects Undergoing Noninvasive Ventilation for Acute Respiratory Failure. Respir Care. 2016; 62 (4): p.459-467. doi: 10.4187/respcare.05003 . | Open in Read by QxMD
  11. Metheny NA, Meert KL, Clouse RE. Complications related to feeding tube placement. Curr Opin Gastroenterol. 2007; 23 (2): p.178-182. doi: 10.1097/mog.0b013e3280287a0f . | Open in Read by QxMD
  12. Stephen A. McClave, Beth E. Taylor, Robert G. Martindale, Malissa M. Warren, Debbie R. Johnson, Carol Braunschweig, Mary S. McCarthy, Evangelia Davanos, Todd W. Rice, Gail A. Cresci, Jane M. Gervasio, Gordon S. Sacks, Pamela R. Roberts, Charlene Compher. Guidelines for the Provision and Assessment of Nutrition Support Therapy in the Adult Critically Ill Patient. J Parenter Enter Nutr. 2016; 40 (2): p.159-211. doi: 10.1177/0148607115621863 . | Open in Read by QxMD
  13. Intrauterine Growth Retardation. https://www.ucsfbenioffchildrens.org/pdf/manuals/21_IUG.pdf. . Accessed: April 1, 2019.
  14. Herbert G, Perry R, Andersen HK, et al. Early enteral nutrition within 24 hours of lower gastrointestinal surgery versus later commencement for length of hospital stay and postoperative complications. Cochrane Database Syst Rev. 2018 . doi: 10.1002/14651858.cd004080.pub3 . | Open in Read by QxMD
  15. Worthington P, Balint J, Bechtold M, et al. When Is Parenteral Nutrition Appropriate?. J Parenter Enteral Nutr. 2017; 41 (3): p.324-377. doi: 10.1177/0148607117695251 . | Open in Read by QxMD
  16. Ayers P, Adams S, Boullata J, et al. A.S.P.E.N. Parenteral Nutrition Safety Consensus Recommendations. J Parenter Enteral Nutr. 2013; 38 (3): p.296-333. doi: 10.1177/0148607113511992 . | Open in Read by QxMD

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