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Part II Nutrition Assessment, Consequences, and Implications BOX 18.5 Determining Parenteral Nutrition Prescription

A. Calculate energy and protein content given final concentrations and volume. Example: D25

AA4.25 L3.0 @ 2,400 mL/d

1. Calculate grams of dextrose, amino acids, and lipids using the formula: (Concentration × volume of solution in liters) × 10

Examples:

(25% dextrose × 2.4 L) × 10 = 600 g dextrose (4.25% amino acids × 2.4 L) × 10 = 102 g amino acids (3% lipids × 2.4 L) × 10 = 72 g lipids

2. Calculate energy for dextrose, amino acids, and lipids by multiplying grams by kilocalories per gram. Examples:

600 g dextrose × 3.4 kcal/g = 2,040 kcal 102 g amino acids × 4 kcal/g = 408 kcal 72 g lipid × 9 kcal/g = 648 kcal

3. Add kilocalories from dextrose, amino acids, and lipids to determine total energy. Example: 2040 + 408 + 648 = 3096 kcal

B. Calculate energy and protein content given volume of base solutions. Example: 357 mL D70

, 1,200 mL AA10 , 250 mL L20

1. Convert volume of base solutions into liters. Examples:

357 mL D70 = 0.357 L of dextrose

1,200 mL AA10 = 1.2 L of amino acids 250 mL L20 = 0.250 L of lipids

2. Multiply volume (L) by number of kilocalories per liter for base solutions. Examples:

0.357 L D70 × 2,380 kcal/L = 850 kcal 1.2 L AA10 × 400 kcal/L = 480 kcal 0.250 L L20 × 2,000 kcal/L = 500 kcal

3. Add kilocalories from base solutions to determine total energy. Example:

850 + 480 + 500 = 1,830 kcal

4. Multiply volume of amino acid solution (L) by grams per liter to determine protein content. Example:

1.2 L AA10 × 100 g/L = 120 g amino acids