Different Types of Clinical Nutrition | Clinical Nutrition LAM Initiative

Different Types of Clinical Nutrition

An Introduction to Enteral and Parenteral Nutrition

When addressing disease-related malnutrition, the choice of nutrition support depends on the patient’s clinical state. The rule of thumb is: “if the gut works, use it.” The majority of patients with, or at risk of malnutrition may be managed using simple tools to increase nutritional intake, including dietary counselling or food fortification. Additional strategies include the use of oral nutritional supplements (ONS). When oral support is not sufficient, tube feeding/enteral or parenteral nutrition may be required alone or in combination. A formal nutrition assessment can determine the correct support therapy based on the patient’s disease-related malnutrition status.1,2,3,4,5,6

The following are the major types of clinical nutrition support:

Enteral Nutrition (EN)

According to the European Society for Clinical Nutrition and Metabolism (ESPEN) Enteral Feeding Guidelines, the term “enteral nutrition” is used to describe all forms of nutritional support that involve the use of ‘‘dietary foods for special medical purposes’’ independent of the route of administration. EN includes ONS and enteral tube feeding.7

Oral Nutritional Supplements (ONS)

ONS is a non-invasive approach to tackle malnutrition. Used as an integral part of an overall patient management strategy, ONS is an effective solution for a wide variety of patient groups. Current evidence suggests that appropriate use of ONS results in nutritional, functional, clinical and economic benefits.8

Tube Feeding

EN tube feeding is introduced via nasogastric, nasoenteral or percutaneous tubes,7 providing nutrients and energy to the mucosal cells, increasing mucosal blood flow, stimulating epithelial cell metabolism, bile flow and pancreatic secretions as well as the release of enterotrophic gastrointestinal (GI) hormones.9

Parenteral Nutrition (PN)

PN is the intravenous infusion of nutrients directly into the systemic circulation, bypassing the gastrointestinal (GI) tract.10 Generally, PN is indicated in patients who cannot be fed adequately and/or safely via the oral/enteral route and/or have a non-functional, inaccessible or perforated gastrointestinal (GI) tract.10,11 Additionally PN can help to improve patient outcomes12,13,14,15 and is safe when indicated and used appropriately.12,15

Supplemental Parenteral Nutrition

In cases where enteral intake cannot sufficiently meet the patient’s daily minimum food and fluid requirements, supplemental PN can be administered in conjunction with EN and can help reduce the risk of EN associated diarrhea in the critical care setting.15,16

Total Parenteral Nutrition

Total PN supplies the patients with all of their daily nutritional requirements in cases where EN is not feasible. Total PN delivers all the nutritional needs of the body intravenously, bypassing the digestive system.

A combination of the mentioned nutritional strategies may be used to manage disease-related malnutrition in an optimal way following a formal nutrition assessment.

  • 1. Heyland DK. Parenteral nutrition in the critically-ill patient: more harm than good? Proc Nutr Soc 2000;59:457-466.
  • 2. Heyland DK, Dhaliwal R, Drover JW et al. Canadian clinical practice guidelines for nutrition support in mechanically ventilated, critically ill adult patients. JPEN 2003;27:355-373.
  • 3. Gramlich L, Kichian K, Pinilla J et al. Does enteral nutrition compared to parenteral nutrition result in better outcomes in critically ill adult patients? A systematic review of the literature. Nutrition 2004;20:843-848.
  • 4. Rubinsky MD, Clark AP. Early enteral nutrition in critically ill patients. Dimens Crit Care Nurs 2012;31:267-274.
  • 5. McClave SA, Martindale RG, Vanek VW et al. Guidelines for the Provision and Assessment of Nutrition Support Therapy in the Adult Critically Ill Patient: Society of Critical Care Medicine (SCCM) and American Society for Parenteral and Enteral Nutrition (A.S.P.E.N.). JPEN 2009;33:277-316.
  • 6. Singer P, Berger MM, Van den Berghe G et al. ESPEN Guidelines on Parenteral Nutrition: intensive care. Clin Nutr 2009;28(4):387-400.
  • 7. a. b. Lochs H, Allison SP, Meier R et al. Introductory to the ESPEN Guidelines on Enteral Nutrition: Terminology, definitions and general topics. Clin Nutr 2006;25(2):180-186.
  • 8. Hubbard GP, Elia M, Holdoway A et al. A systematic review of compliance to oral nutritional supplements. Clin Nutr. 2012;31(3):293-312.
  • 9. Druml W. Clinical strategies for prevention of bacterial translocation. In: Herbert MK, editor. Problems of the gastrointestinal tract in anesthesia. Springer Verlag 1999:118-126.
  • 10. a. b. National Collaborating Centre for Acute Care (UK). Nutrition Support for Adults Oral Nutrition Support, Enteral Tube Feeding and Parenteral Nutrition. NICE Clinical Guidelines, No. 32 London 2006.
  • 11. Rothaermel S, Bischoff SC, Bockenheimer-Lucius G et al. Ethical and legal points of view in parenteral nutrition - guidelines on parenteral nutrition chapter 12. Ger Med Sci 2009;7:Doc16.
  • 12. a. b. Doig GS, Simpson F, Sweetman EA et al. Early parenteral nutrition in critically ill patients with short-term relative contraindications to early enteral nutrition: a randomized controlled trial. JAMA 2013;309(20):2130-2138.
  • 13. Doig GS, Simpson F, Early PN Trial Investigators Group. Early parenteral nutrition in critically ill patients with short-term relative contraindications to early enteral nutrition: a full economic analysis of a multicenter randomized controlled trial based on US costs. Clinicoecon Outcomes Res 2013;5:369-379.
  • 14. Heidegger CP, Berger MM, Graf S et al. Optimisation of energy provision with supplemental parenteral nutrition in critically ill patients: a randomised controlled clinical trial. Lancet 2013;381(9864):385-393.
  • 15. a. b. c. Thibault R, Heidegger CP, Berger MM et al. Parenteral nutrition in the intensive care unit: cautious use improves outcome. Swiss Med Wkly 2014;144:w13997.
  • 16. Thibault R, Graf S, Clerc A et al. Diarrhoea in the ICU: respective contribution of feeding and antibiotics. Crit Care 2013;17(4):R153.

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