# Bedside TPN: The Practicing Surgeon

B Phillips

###### Keywords

medicine, nutrition, parenteral nutrition, pharmacology, tpn

###### Citation

B Phillips. *Bedside TPN: The Practicing Surgeon*. The Internet Journal of Surgery. 2000 Volume 2 Number 1.

###### Abstract

We present an easy way to calculate the requirements and components of a total parenteral nutrition TPN.

### 1. Calculate IBW (Ideal Body Weight)

Male: 106 lbs for the first 5’ & 6 lbs per inch after

Female: 100 lbs for the first 5’ & 5 lbs per inch after

e.g. 5’10” male - 106 + 60 = 166 lbs

(now divide by 2.2 lbs/kg)

= 75.5 kgs

### 2. Calculate Protein Need

e.g. 76 kgs x 1.5 g/kg/day

114 g protein/day Needed

### 3. Calculate Non-Protein Calories

e.g. 76 kg x 25 kcal/kg/d

1900 kcal/day Needed

### 4. Determine CHO:Lipid Ratio

estimate need based on patient disease

e.g. 1900 kcal/day Needed from Non-Protein Calories

### 5. Now, Calculate Grams Needed & ml of Solution

a.

e.g. 1330 kcal/day Needed from CHO

1330 / 3.4 = 391 g CHO/day needed

e.g. 391 g Needed = 782 ml, D50 Solution

or

= 559 ml, D70 Solution

b.

e.g. 570 kcal Lipids Needed/day = 63 g Lipids Needed/day

take the # kcal needed and divide by 2, to determine the number of ml of a 20 % lipid solution

e.g. 570 kcal/day needed = 285 cc of a 20 % Lipid Soln.

(29 cc/hr x 10 hrs)

### 6. Calculate Total Fluids Needed

e.g. 76 kg Male, 30 cc/kg/day Fluid = 2280 cc/fluid/day

(this is administered separate from the TPN Soln)

e.g. 2280 cc - 285 cc = 1995 cc TPN + Fluid/day

e.g. 1995cc / 24 hrs = 83 cc TPN Soln. / hr