CSPT Sterile Compounding Calculations 3

Question 1

A TPN order requires 500 mEq of sodium chloride. How many mL of 23.4% NaCl (4 mEq/mL) are needed?

Accepted Answer

125 mL

Answer

500 mEq ÷ 4 mEq/mL = 125 mL.

Question 2

An IV solution contains 1 g of drug in 250 mL. What is the concentration in mg/mL?

Accepted Answer

4 mg/mL

Answer

1 g = 1000 mg; 1000 mg ÷ 250 mL = 4 mg/mL.

Question 3

A pediatric patient weighs 22 lbs. A drug is dosed at 10 mg/kg/day. What is the daily dose?

Accepted Answer

100 mg

Answer

22 lbs ÷ 2.2 = 10 kg; 10 kg × 10 mg/kg = 100 mg/day.

Question 4

You need to prepare 200 mL of a 0.5% solution from a 2% stock solution. How many mL of stock do you need?

Accepted Answer

50 mL

Answer

C1V1 = C2V2 → 2% × V1 = 0.5% × 200 mL → V1 = 50 mL.

Question 5

A continuous infusion is ordered at 15 mL/hr. How many hours will a 250 mL bag last?

Accepted Answer

16.7 hours

Answer

250 mL ÷ 15 mL/hr ≈ 16.7 hours.

CSPT - Compounded Sterile Preparation Technician Practice Test