CSPT Compounding Calculations 5

Question 1

A pediatric patient needs gentamicin 2.5 mg/kg IV q8h. The child weighs 22 lbs. What is the single dose in mg?

Accepted Answer

12.5 mg

Answer

22 lbs ÷ 2.2 = 10 kg; 10 kg × 2.5 mg/kg = 25 mg — answer index 1 is 25 mg.

Question 2

How many mL of sterile water for injection must be added to 50 mL of a 50% dextrose solution to produce a 25% dextrose solution?

Accepted Answer

50 mL

Answer

C1V1 = C2V2 → 50% × 50 mL = 25% × V2 → V2 = 100 mL; SWFI needed = 100 − 50 = 50 mL.

Question 3

A morphine PCA bag contains 50 mg in 50 mL NS. The PCA is programmed for 1 mg demand doses. What volume delivers each demand dose?

Accepted Answer

1 mL

Answer

Concentration = 50 mg/50 mL = 1 mg/mL; 1 mg dose ÷ 1 mg/mL = 1 mL.

Question 4

Amino acids provide 4 kcal/g. A TPN contains 85 g of amino acids. How many kcal do the amino acids contribute?

Accepted Answer

340 kcal

Answer

85 g × 4 kcal/g = 340 kcal.

Question 5

You are preparing an IV admixture and need to add calcium gluconate 1 g. The available vial is 10% (100 mg/mL). How many mL do you draw up?

Accepted Answer

10 mL

Answer

1 g = 1000 mg; 1000 mg ÷ 100 mg/mL = 10 mL.

CSPT - Compounded Sterile Preparation Technician Practice Test