Administering Parenteral Nutrition
Considerations for Methods of Parenteral Nutrition Delivery
When parenteral nutrition (PN) is indicated, solutions are administered either via a central venous catheter or peripheral venous cannulas.1
The delivery of PN may be classified according to different aspects, such as insertion site, insertion method or duration of treatment.2
- Condition of the patient (type of illness, current state of health, etc.)
- Accessibility of the venous system
- Composition of the infused solution and amount of energy to be administered
- Osmolarity of PN products
- Planned duration of PN (short-term or long-term)
Central Venous PN Administration
According to the recommendations of the European Society for Clinical Nutrition and Metabolism (ESPEN), central venous access is called for in the majority of patients with the following conditions:4
- Need for long-term nutritional support of greater than one month
- Poor peripheral veins
- Need for hyperosmolar solutions (osmolarity greater than 850 mosmol/l)
- Glucose concentration greater than 12.5 percent2
- High nutrient requirements
- Severe fluid restriction
- Administration of solution with pH lower than five or greater than nine
- Need for multiple lumen intravenous treatment
Central catheters are usually inserted into a central vein, with the catheter tip being located in the lower third of the superior vena cava or in the upper right atrium.4
Peripheral Venous PN Administration
The osmolarity of the parenteral solution, which refers to the number of osmotically active particles in one liter of solution, is a crucial factor in determining the feasibility of peripheral PN (PPN). When a PN solution with a high osmolarity is introduced into a small vein with a low blood flow, the mixture becomes hypertonic and fluid from the surrounding tissue moves into the vein due to osmosis. Local inflammation can induce thrombosis.
Lipid emulsions are isotonic with blood and exert a soothing effect on the veins. For this reason, PN admixtures containing lipid emulsions are less hypertonic than emulsions based solely on glucose as an energy source, and, consequently, more suitable for PPN.3
Prevention of peripheral vein thrombophlebitis according to ESPEN:4
- Aseptic techniques during catheter placement and care
- Choice of the smallest gauge possible
- Use of polyurethane and silicone catheters
- Use of lipid based solutions
- Appropriate osmolarity of the solution
- Administration of solutions with pH between five and nine
- Adequate fixation (transparent adhesive membranes or sutureless fixation devices)
Contraindications for Nutrition Support
Contraindications for nutrition support via enteral and parenteral routes include:5
- Acute phase (“ebb-phase”) during the first hours after trauma, surgery, or the onset of severe infection
- Serum lactate >3 mmol/l
- Hypoxia (paO2 <50 mm Hg)
- Severe acidosis (pH <7.2)
- 1. a. b. Jauch KW, Schregel W, Stanga Z et al. Access technique and its problems in parenteral nutrition. Guidelines on Parenteral Nutrition, Chapter 9. Ger Med Sci 2009;7(19):1-18.
- 2. a. b. c. Pertkiewicz M, Dudrick SJ et al. Parenteral nutrition. In: Sobotka L, editor. Basics in Clinical Nutrition. Prague: Galen, 2011:348-417.
- 3. a. b. c. 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.
- 4. a. b. c. d. e. Pittiruti M, Hamilton H, Biffi R et al. ESPEN Guidelines on Parenteral Nutrition: Central Venous Catheters (access, care, diagnosis and therapy of complications). Clin Nutr 2009;28(4):365-377.
- 5. Austrian Society of Clinical Nutrition (AKE). Recommendations for enteral and parenteral nutrition in adults. Vienna 2008.