Adult TPN Calculations

 

> Calorie/Protein Requirements
> Calorie/Protein Yields
> Electrolyte Requirements
> Adult Fluid Requirements
> Adult Energy Requirements

 

Calorie/Protein Requirements
Condit. Calories
(kcal/
kg/d)
Protein
(gm/
kg/d)
Resting
state
20-30 0.8-1
Uncomp
postop
25-35 1-1.3
Depleted 30-40 1.3-1.7
Hyper-
metabolic
5-45 1.5-2

 

Calorie/Protein Yields
1 Gm
protein
4 kcals
1 Gm fat 9 kcals
1 Gm
dextrose
3.4 kcals
1 Gm
nitrogen
6.25gm
protein

 

Electrolyte Requirements
Salt mEq/day
Sodium 60-120
Potassium 60-120
Chloride 100-150
Magnesium 10-24
Calcium 10-20
Phosphate 20-50mM
Sulfate 10-24
Acetate 60-150
Bicarbonate incomp

 

Adult Fluid Requirements
30-35 ml/kg/day
-or-
1,500ml for first 20kg,
then 20ml/kg for weight > 20kg

 

Adult Energy Requirements
--Steps:
   1. Calculate BEE
   2. Determine activity/injury factors
   3. Calculate TDE

 

1. Basal Energy Expenditure (BEE)
Harris Benedict equation:
BEE for females =
66.67+(13.75*kg)+(58*cm)-(6.76*y)
BEE for males =
66.51+(9.56*kg)+(1.85*cm)-(4.68*y)

 

2. Activity Factors:
confined to bed 1.2
out of bed 1.3

 

2. Injury Factors
minor surgery 1-1.1
major surgery 1.1-1.2
mild infection 1-1.2
moderate
infection
1.2-1.4
severe
infection
1.4-1.8
skeletal
trauma
1.2-1.36
head injury
(on steroids)
1.6
blunt trauma 1.15-1.35
burns
<20% BSA
2
burns
20-30% BSA
2-2.2
burns
>30% BSA
2.2

 

3. Total Daily Energy Expenditure
TDE=(BEE)*[(activity factor)+(injury factor)]