Specialized nutrition support

Last updated: March 9, 2023

Summarytoggle arrow icon

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.

Approachtoggle arrow icon

General principles [1][2]

  • Consult a nutritionist if available. [3]
  • Consider specialized nutrition support in:
    • Hospitalized patients who are both: [2]
    • 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!

Enteral nutritiontoggle arrow icon

Enteral feeding is 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

Percutaneous access

Percutaneous access is indicated if nutritional support is anticipated for approx. > 4 weeks and inserted surgically, fluoroscopically, or endoscopically.

  • Gastrostomy tube (G tube) [9][10]
    • Inserted into the stomach through an incision in the abdominal wall
    • Example: endoscopically inserted percutaneous endoscopic gastrostomy (PEG) tube
  • Jejunostomy tube (J tube)
  • Gastrojejunostomy tube (GJ tube)
    • Inserted into the stomach through an incision in the abdominal wall, with an additional tube threaded into the jejunum
    • Used to provide postpyloric feeding and to vent the stomach

Contraindications [7][11]

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

Aspiration prevention [3][11][12]

  • 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 [11]

  • 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][11][13]

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

Enteral nutrition-specific complications [3][7][11]

Nutrition related

Access related

Management of G tube complications [9][10]

  • All patients with complications
    • Stop tube feed.
    • Consult specialty service, e.g., surgery, interventional radiology.
  • Tube blockage [18]
    • Instill warm water with a 30–60 mL syringe and apply gentle back-and-forth pressure on the plunger. [18]
    • If unsuccessful: Instill activated pancreatic enzyme solution, clamp the G tube, and reattempt flushing after 30 minutes.
    • If the obstruction remains, consider using a declogging brush and/or tube replacement.
  • Infection: Consider antibiotics.
  • Early dislodgement (< 4 weeks after placement)
    • Endoscopic replacement is usually required.
    • Do not attempt blind reinsertion.
    • Admit for specialist consult and monitor for signs of peritonitis.
  • Late dislodgement (> 4 weeks after placement)
    • Bedside G tube replacement can be safely attempted for late dislodgement. [10]
    • Place a new G tube or, if a new G tube is not immediately available, a foley catheter. [10][19]
    • Inflate the gastrostomy tube balloon and confirm correct placement before resuming tube feed. [19]

Do not attempt to unclog a G tube with forceful irrigation or carbonated beverages, as this can worsen occlusion and/or lead to tube rupture. [19]

For tube dislodgement > 4 weeks after placement, immediately stent the tract with a new G tube or a foley catheter to prevent tract closure. [10]

Parenteral nutritiontoggle arrow icon

Definition [11]

  • 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 [20]

Composition of parenteral feeding solutions [11]

Parenteral nutrition-specific complications [11]

Metabolic complicationstoggle arrow icon

Intestinal failure-associated liver diseasetoggle arrow icon

Referencestoggle arrow icon

  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. Kohli D. Comparative outcomes of endoscopic and radiological gastrostomy tube placement: a systematic review and meta-analysis with GRADE analysis. Ann Gastroenterol. 2022.doi: 10.20524/aog.2022.0752 . | Open in Read by QxMD
  4. Abdelfattah T, Kaspar M. Gastroenterologist’s Guide to Gastrostomies. Dig Dis Sci. 2022; 67 (8): p.3488-3496.doi: 10.1007/s10620-022-07538-0 . | Open in Read by QxMD
  5. 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
  6. 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
  7. 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
  8. Kulick D, Deen D. Specialized Nutrition Support. Am Fam Physician. 2011; Volume 83 (Number 2).
  9. 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
  10. 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
  11. 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
  12. 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
  13. 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
  14. Sealock RJ, Munot K. Common Gastrostomy Feeding Tube Complications and Troubleshooting. Clin Gastroenterol Hepatol. 2018; 16 (12): p.1864-1869.doi: 10.1016/j.cgh.2018.07.037 . | Open in Read by QxMD
  15. Boullata JI, Carrera AL, Harvey L, et al. ASPEN Safe Practices for Enteral Nutrition Therapy. Journal of Parenteral and Enteral Nutrition. 2016; 41 (1): p.15-103.doi: 10.1177/0148607116673053 . | Open in Read by QxMD
  16. Roberts JR. Roberts and Hedges' Clinical Procedures in Emergency Medicine and Acute Care. Elsevier ; 2018
  17. 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
  18. Intrauterine Growth Retardation. . Accessed: April 1, 2019.
  19. 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
  20. 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
  21. 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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