Components of Parenteral Nutrition
The Four Critical Components of Parenteral Nutrition
In general, parenteral nutrition (PN) is typically composed of four critical components:
Fluids and Electrolytes
Water is quantitatively the most important component of the human body, making fluid replacement a key objective of PN therapy. Whole body water is divided between two compartments, the extracellular (EC) and intracellular (IC) space. These contain a number of electrolytes, e.g. sodium, potassium, magnesium, phosphate and calcium, in different concentrations.1
Macronutrients are needed for growth, metabolism, and other normal body functions. Total PN implies that all nutrients are given intravenously to the patient and no significant nutrition is obtained by other routes. The proper PN therapy consists of a precise balance of:
- Amino acids: Supply with PN by free amino acids and/or dipeptides, which are essential to maintain cellular integrity and function, acting as structural, transport and signaling molecules. Amino acids should always be co-administered with glucose to prevent wasting of amino acids for endogenous glucose production.2,3
- Lipids: Supply with PN by soybean oil, olive oil, medium-chain triglycerides (MCT), fish oil. Lipids are the primary energy substrate and the main energy store in the human body.4,5,6,7,8
- Carbohydrates: Supply with PN by glucose, which serves as the main energy source. In addition, glucose supply prevents wasting amino acids that would otherwise be used for energy production instead of carbohydrates.9,10
In clinical nutrition, micronutrients are necessary to avoid or correct deficiency states, and to help maintain normal metabolism and antioxidant statuses. In total, 13 vitamins and 9 essential trace elements should be provided with PN.11
- Vitamins should include:
- B2 (Riboflavine)
- B3 (Niacin)
- B5 (Pantothenate)
- B6 (Pyridoxin)
- B12 (Cyanocobalamin)
- B9 (Folic acid)
- C (Ascorbate)
- A (Retinol)
- D (Cholecaliciferol)
- E (Tocopherol)
- K (Phylloquinone)
- Trace elements should include:
- 1. Morlion BJ. Water, electrolytes and acid-base metabolism. In: Biesalski HK et al., editors. Nutritional Medicine. Stuttgart: Thieme 2004:159-166.
- 2. Institute of Medicine (US) Panel on Macronutrients; Institute of Medicine (US) Standing Committee on the Scientific Evaluation of Dietary Reference Intakes. Dietary reference intakes for energy, carbohydrate, fiber, fat, fatty acids, cholesterol, protein, and amino acids. Washington D.C: National Academic Press 2005. Washington, DC : National Academies Press, 2005.
- 3. Fürst P, Deutz NEP, Boirie Y et al. Proteins and amino acids. In: Sobotka L, editor. Basics in Clinical Nutrition. Prague: Galen 2011:262-268.
- 4. Koletzko B, Goulet O, Hunt J et al. 1. Guidelines on Paediatric Parenteral Nutrition of the European Society of Paediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) and the European Society for Clinical Nutrition and Metabolism (ESPEN), Supported by the European Society of Paediatric Research (ESPR). J Pediatr Gastroenterol Nutr 2005;41 Suppl 2:S1-87.
- 5. Adolph M, Heller AR, Koch T et al. Lipid emulsions - guidelines on parenteral nutrition, chapter 6. Ger Med Sci 2009;7:Doc22.
- 6. Carpentier Y, Sobotka L. Lipids. In: Sobotka L, editor. Basics in Clinical Nutrition. Prague: Galen 2011:257-262.
- 7. Grimble RF. Fatty acid profile of modern lipid emulsions: Scientific considerations for creating the ideal composition. Clinical Nutrition Supplements 2005;1:9-15.
- 8. Wanten GJ, Calder PC. Immune modulation by parenteral lipid emulsions. Am J Clin Nutr 2007;85:1171-1184.
- 9. Carpentier Y, Sobotka L, Soeters P. Carbohydrates. In: Sobotka L, editor. Basics in Clinical Nutrition. Galen 2011:252-257.
- 10. Bolder U, Ebener C, Hauner H et al. Carbohydrates - guidelines on parenteral nutrition, chapter 5. Ger Med Sci 2009;7:Doc23.
- 11. Staun M, Pironi L, Bozzetti F et al. ESPEN Guidelines on Parenteral Nutrition: home parenteral nutrition (HPN) in adult patients. Clin Nutr 2009;28:467-479.