Nutrition calculations

Question 1

Dietary carbohydrate and enteral nutirion carbs = x kcal

Answer 1

4 kcal/gram

Dextrose in PN has 3.4 kcal/gram
Glycerol in PN has 4.3 kcal/gram (not used often)

Question 2

Fats = x kcal/g

Answer 2

9 kcal/gram

10% fat emulsion = 1.1 kcal/mL
20 % = 2 kcal/mL
30 % = 3 kcal/mL

Question 3

Protein = x kcal/g

Answer 3

4 kcal/mL

Question 4

Indications for PN

Answer 4

bowel obstruction
ileus
severe diarrhea
malabsorption

Question 5

Equation for determining fluid needs

Answer 5

Pts > 20 kg:
1500 mL + (20 ml) (wt - 20 kg)
General guideline:
30-40 ml/kg/day

Question 6

Basal Energy Expenditure (BEE) equation estimation

Answer 6

15 - 25 kcal/kg (adults)

Question 7

Total Energy expenditiure (TEE) equation

Answer 7

BEE x activity factor x stress factor

Question 8

Calculating protein needs

Answer 8

0. 8-1 g/kg/day (ambulatory, non-hospitalized)

1. 2-2 g/kg/ day (Hospitalized, malnourished)

Question 9

Which element is release from protein catabolism?

Answer 9

Nitrogen
1 gram of Nitrogen for each 6.25 g of protein

Nitrogen intake = g of protein intake/ 6.25

Question 10

Usual proportion of non-protein calories in PN

Answer 10

70 - 85% of carbs

15 - 30 % of fats

Question 11

What size filter is used for lipid emulsions?

Answer 11

1.2 micron filters

Question 12

The major extracellular cation

Answer 12

Sodium
23.4 % sodium chloride = 4 mEq/mL
Sodium acetate is preferred in PN if pt is acidotic

Question 13

The major intracellular cation

Answer 13

potassium

Question 14

Corrected calcium

Answer 14

when albumin is less than 3.5

= serum calcium + [(4.0 - albumin) x 0.8]

Question 15

Rules for adding Ca and Phos to PN

Answer 15

Ca and Phos can bind together and form precipatates
Use calcium gluconate
add Phos first, add calcium at the end
keep mixed bag in fridge until ready for admin
do not exceed a total of 45 mEq/L

Question 16

Fat soluble vitamins in PN mixture [4]

Answer 16

Vit A, D, E K (some mixtures do not have Vit K- MVI-12)

Question 17

Water soluble vitamins in PN mixture [9]

Answer 17

thiamine (b1), riboflavin (b2), niacin (b3), pantothenic acid, pyridoxine (b6), asocrbic acid (vit C), folic acid (b9), cyancobalamin (b12), biotin

Question 18

Trace elements used in PN

Answer 18

zinc
copper
chromium
manganese
selenium

Question 19

General rule for separating drugs and enteral feedings

Answer 19

hold feeding 1 hr before and 2 hrs after the drug

some drugs might require further separation

Question 20

Specific drug-nutrient interactions with tube feedings

Answer 20

Warfarin: feedings can bind to drug and lower INR
TetracyclineL chelates with Ca, Mg, etc
Cipro: Cipro suspension cannot be used bc it adheres to the feeding tube; crush up IR tabs and mix with water
Phenytoin suspension: binds to feedings, leads to decr drug levels