What are the latest guidelines for parenteral nutrition (PN) composition and administration?

Latest Guidelines for Parenteral Nutrition Composition and Administration

According to the latest ESPEN guidelines, parenteral nutrition (PN) should be administered using three-chamber bags or all-in-one admixtures that combine amino acids, glucose, and lipid emulsions in a single infusate, along with electrolytes, vitamins, and trace elements as required. 1

Composition of Parenteral Nutrition

Macronutrients

1. Carbohydrates

   • Glucose should provide 50-60% of non-protein energy requirements 1
   • Minimal amount required: approximately 2 g/kg/day 1
   • Avoid hyperglycemia (>10 mmol/L) as it contributes to increased mortality and infectious complications 1

2. Lipids

   • Should constitute an integral part of PN for energy and essential fatty acid provision 1
   • Recommended ratio: 1/3 of calories from lipids, 2/3 from glucose 1
   • Administration rate: 0.7-1.5 g/kg over 12-24 hours 1
   • Limit to no more than 1 g/kg/day of standard lipid emulsions to prevent liver complications 1
   • Prefer lipid emulsions with lower n-6 unsaturated fatty acids than traditional pure soybean oil emulsions 1
   • Mixed LCT/MCT emulsions or olive oil-based formulations are well-tolerated alternatives 1
   • Fish oil-enriched lipid emulsions containing EPA and DHA may decrease length of stay in critically ill patients 1

3. Amino Acids

   • Recommended dosage: 1.2-1.5 g/kg/day in most patients 1
   • For ICU patients, amino acid solutions should contain 0.2-0.4 g/kg/day of L-glutamine 1

Micronutrients

1. Vitamins and Trace Elements

   • All PN prescriptions should include a daily dose of multivitamins and trace elements 1
   • Water-soluble vitamins and trace elements should be given daily from the first day of PN 1
   • Administer vitamin B1 prior to starting glucose infusion in alcoholic patients to reduce the risk of Wernicke's encephalopathy 1

2. Electrolytes and Minerals

   • Individualized based on serum levels and losses
   • Special attention to sodium, potassium, and magnesium balance, especially in patients with high output stomas 1
   • Monitor phosphate, potassium, and magnesium levels when refeeding malnourished patients 1

Administration Methods

Delivery Systems

1. Three-chamber bag/All-in-one PN

   • Preferred method of administration 1
   • Contains all macronutrients and electrolytes in separate compartments
   • Substrates mixed immediately prior to administration
   • Advantages: reduced risk of infection due to closed system and reduced manipulation 1
   • Available with or without basic electrolytes; vitamins and trace elements are added prior to administration 1

2. Two-chamber bag/Two-in-one PN

   • Alternative when a formulation is pharmaceutically unstable with lipids 1
   • Contains amino acids and glucose (no lipid emulsion) in a single infusate

Access Routes

1. Central Venous Access

   • Required for high osmolarity PN mixtures designed to cover nutritional needs fully 1
   • Preferred for long-term PN administration

2. Peripheral Venous Access

   • May be considered for low osmolarity (<850 mOsmol/L) mixtures 1
   • Suitable for short-term supplemental PN to mitigate negative energy balance

Energy Requirements and Monitoring

1. Energy Provision

   • During acute illness: provide energy as close as possible to measured energy expenditure 1
   • In absence of indirect calorimetry: start with 25 kcal/kg/day, increasing to target over 2-3 days 1
   • For patients with chronic intestinal failure: total energy should comprise between 0.85-1.5 times the resting energy expenditure 1

2. Monitoring Parameters

   • Regular blood glucose monitoring to detect hypoglycemia and avoid PN-related hyperglycemia 1
   • Monitor electrolytes, especially in malnourished patients at risk of refeeding syndrome 1
   • Regular assessment of liver function, especially with long-term PN 1

Special Considerations

1. Supplementary PN with Enteral Nutrition

   • Consider supplementary PN for patients receiving less than targeted enteral feeding after 2 days 1

2. Home Parenteral Nutrition

   • Design regimens to be provided on as few nights as possible while ensuring correct fluid balance 1
   • Usually administered overnight to allow normal daytime activities 1
   • Each PN cycle should be complete, with adjustments made to the number of cycles per week 1

3. Timing of Initiation

   • Start PN immediately in moderately or severely malnourished patients who cannot be fed sufficiently orally or enterally 1
   • For patients who must abstain from food, provide IV glucose (2-3 g/kg/day) after 12 hours and consider PN if fasting exceeds 72 hours 1

By following these evidence-based guidelines for PN composition and administration, clinicians can optimize nutritional support while minimizing complications, ultimately improving patient outcomes in terms of morbidity, mortality, and quality of life.