How to Calculate Components in Neonatal TPN

Newborn infants are fragile creatures. At times, complications resulting from prematurity or illness may interfere with a baby's ability to feed via the gastrointestinal tract. In these cases, it may be necessary to supply nutrition intravenously, a method known as "total parenteral nutrition" or TPN. TPN for neonates contains all of the essential components required to prevent deficiency and maintain normal growth rates, including protein, carbohydrate, fat, electrolytes, vitamins and minerals. A proper balance of these nutrients will support the infant's speedy recovery.

Instructions

• 1

  Calculate the amount of protein the TPN formula should include by using 2 to 3 grams of amino acids per kilogram per day to begin with and advancing to no more than 3 grams per kilogram per day, according to UCSF Benioff Children's Hospital's 2006 Intensive Care Nursery House Staff Manual. For example, a baby that weighs 3 kg should receive a maximum of 9 g of amino acids per day.

• 2

  Calculate the amount of carbohydrate that should be included in the TPN formula by using 4 to 6 milligrams of dextrose monohydrate per kilogram per minute and gradually increasing to no more than 12 milligrams per kilogram per minute. For example, a 3 kg infant should receive a maximum of 36 mg per minute.

• 3

  Calculate the amount of fat needed in the TPN formula using the rate of 0.25 to 0.5 grams per kilogram per day to prevent a deficiency in essential fatty acids. For example, a 3 kg baby should receive at least 0.75 g of lipids per day.

• 4

  Determine if calorie needs are being met. The minimal amount needed to prevent catabolism is 40 kilocalories per kilogram per day. To sustain continued growth, a goal of 100 kilocalories per kilogram per day should be met. Use the following conversion factors to convert grams of each macronutrient to kilocalories: 1 g amino acids = 4 kcal, 1 g dextrose = 3.4 kcal and 1 g lipids = 10 kcal. (For dextrose, be careful to convert milligrams to grams and minutes to days before using the conversion factor.)

• 5

  Determine the calorie percentage of each macronutrient and make sure that lipids do not exceed 60 percent of the total caloric intake.

• 6

  Choose the appropriate dextrose/amino acids solution and lipid emulsion that meet the calculated requirements.

• 7

  Account for electrolytes, vitamins and minerals according to the suggested ranges on the TPN order form.

• 8

  Monitor laboratory values and make adjustments as needed to keep the TPN in an appropriate balance that will support the infant's growth and recovery.