Determine 24 hr volume (maintenance, > / <?)
determine final energy goal - kcal/kg
Start IV dextrose (3.4 kcal/g) at 10-12.5% (= max if peripheral);
by 2.5%/d to goal (50-60% of kcal); typical goal for CHO is 15-20% dextrose
Determine daily protein needs (g/kg), based on age, stress, etc. (goal ~ 8-10% of kcal; 4 kcal/g)
Divide g/d into volume = % amino acids
Choose Trophamine if young infant, especially for premature infants, and for patients with cholestatic liver disease
: start at 0.5-1.0 g/kg/d; divide g/d by 0.2 (
multiply by 5) to obtain volume of 20% lipid emulsion needed (in milliliters or cc). 20% lipid emulsion has 2 kcal/cc and 10 kcal/gram of lipid.
Advance to goal to provide ~30-40% of kcal from lipids, but do not exceed maximum grams/kg based on age (see guidelines under lipid section).
Electrolytes & minerals
: use standard formulation unless imbalances present;
Standard electrolytes provide
¼ NS + 25 meq K (as combination KCL & KP)
Trace minerals & Vitamins
- check off standard preparations unless specific alterations are necessary.
EXAMPLE TPN CALCULATION:
Calculate a TPN solution for a 6 mo, 5 kg infant, w/ diarrhea, feeding intolerance, & moderately underweight; TPN to provide all maintenance fluid & Nutrition Support
First determine Fluid needs.
At maintenance, this is 500 cc/24 hours
Next determine goal energy needs.
Upper end of the range for age is 90 kcal/kg. Given that this infant is underweight, there is a good chance he will need more than this to gain well. Daily monitoring will be essential to ensure that his goal TPN is meeting his nutrition goals. Initial kcal goal is 450 kcal/d.
Next determine protein needs.
Goal for this infant is 2 g/kg = 10 g; 10g/500 cc = 2 %. 10 grams x 4 kcal/g = 40 kcal.
Next determine goal lipid intake.
For our patient it is 3.0 g/kg. This is 15 grams; 15g x 10 kcal/g = 150 kcal. Goal volume of 20% lipid needed is 75 cc. Start with 1g/kg/day = 5 g/ .2 = 25 cc lipid. Advance by 1g/kg daily as tolerated to 3 g/kg/d.
Finally, determine carbohydrate intake
. This is easily done by taking goal calories, subtracting calories provided from protein and lipid, and dividing the remaining calories by 3.4 kcal/gram to get g of dextrose.
450 kcal - 40 kcal (amino acids)- 150 kcal (lipid) = 260 kcal from dextrose
260 kcal/ 3.4 kcal/gram = 76 grams dextrose.
76 g/ 500 cc TPN = 15.3 % (can round to nearest .5%, so 15.5%)
Start TPN at 10 - 12.5% and advance by 2.5% qd to goal of 15.5%
Review final solution and calculations:
Goal solution is 500 cc 15.5% dextrose, 2 % amino acids, 75 cc Lipid =
500 cc x 15.5 % = 77.5 grams x 3.4 kcal/g = 263.5 kcal
500 cc x 2% = 10 grams x 4 kcal/g = 40 kcal.
75 cc lipid x 2 kcal/cc = 150 kcal.
Total kcal = 263.5 + 40 + 150 = 453.4 or 90.7 kcal/kg.
Order electrolytes, minerals
- order standard or adjust based on initial labs.
Order vitamins and trace minerals
- start with standard unless deficiencies are known or there is evidence of increased losses or need.
- SET GOALS & DOCUMENT THEM
- MONITOR WHETHER/WHEN GOALS ARE MET OR IF NEED RE-ADJUSTMENT
- MONITOR FOR TOLERANCE/COMPLICATIONS
- USE THE GI TRACT & WEAN TPN AS ABLE!!