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HESI RN DOSAGE CALCULATION IV EXAM WITH
QUESTIONS AND ANSWERS 2025-26 VERSION
Question 1:
The healthcare provider prescribes cefazolin 800 mg IM every 6 hours. The available vial
is labeled, "Cefazolin 1 gram," and the instructions for reconstitution state, "For IM use,
add 2.5 mL sterile water for injection to provide a total volume of 3.0 mL." How many mL
should the nurse administer? (Enter numerical value only. If rounding is required, round
to the nearest tenth.)
Explanation
Correct Answer (mL) : 2.4
Solution
Here's how to calculate the volume (mL) of the reconstituted cefazolin solution the nurse
should administer for each dose:
1. We know the following:
Prescribed dose: 800 mg cefazolin (given)
Vial information:
Contains 1 gram cefazolin (given) = 1000 mg (since 1 gram = 1000 milligrams)
Reconstituted with 2.5 mL sterile water for injection (given)
Yields a total volume of 3.0 mL (given)
2. We need to find the concentration of cefazolin (mg/mL) in the reconstituted solution.
3. Then, we can find the volume (mL) to administer for the prescribed dose (800 mg)
considering the concentration.
Steps:
a. Calculate the concentration after reconstitution:
Total volume after reconstitution = 3.0 mL (given)
Total amount of cefazolin after reconstitution = 1 gram (from the vial) = 1000 mg
Concentration (mg/mL) = Total amount of medication (mg) / Total volume after
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reconstitution (mL)
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Concentration (mg/mL) = 1000 mg / 3.0 mL
Concentration (mg/mL) = 333.33 mg/mL (round to one decimal place)
b. Calculate the volume to administer:
Volume to administer (mL) = Dose (mg) / Concentration (mg/mL)
Volume to administer (mL) = 800 mg / 333.33 mg/mL
Volume to administer (mL) = 2.4 mL (round to nearest tenth)
Therefore, the nurse should administer approximately 2.4 mL of the reconstituted
cefazolin solution intramuscularly every 6 hours.
Question 2:
The nurse is preparing a client's dose of an IM analgesic in a single syringe. The
prescription is hydromorphone 4 mg and hydroxyzine 25 mg. The
hydromorphone is available in a 10 mg/ml, ampule, and the hydroxyzine is
available in a 50 mg/ml, vial. How many total mL should the nurse administer?
(Enter the numeric value only. If rounding is required, round to the nearest tenth.)
Explanation
Correct Answer (mL) : 0.9
Solution
Here's how to calculate the total volume (mL) the nurse should administer for the
combined medication dose
1. Calculate the volume for each medication:
Hydromorphone:
Dose: 4 mg (given)
Concentration: 10 mg/mL (given)
Volume (mL) = Dose (mg) / Concentration (mg/mL)
Volume (mL) = 4 mg / 10 mg/mL
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Volume (mL) = 0.4 mL
Hydroxyzine:
Dose: 25 mg (given)
Concentration: 50 mg/mL (given)
Volume (mL) = Dose (mg) / Concentration (mg/mL)
Volume (mL) = 25 mg / 50 mg/mL
Volume (mL) = 0.5 mL
2. Add the volumes for each medication to find the total volume:
Total volume (mL) = Volume of hydromorphone (mL) + Volume of hydroxyzine (mL)
Total volume (mL) = 0.4 mL + 0.5 mL
Total volume (mL) = 0.9 mL (round to nearest tenth)
Therefore, the nurse should administer a total of 0.9 mL.
Question 3:
A client is receiving IV dextrose 5% in water (DSW) at 125 mL/hour and a secondary
infusion of pantoprazole 40 mg IV daily. The pharmacy provides a 110 mL premixed
solution of pantoprazole to be infused over 15 minutes. The nurse should program the
secondary infusion to deliver how many mL/hour? (Enter numeric value only.)
Explanation
Correct Answer (mL/hour) : 440
Solution
While the primary infusion rate (dextrose 5% in water) and the total volume of
pantoprazole solution are provided, the pantoprazole infusion doesn't directly affect the
rate of the primary DSW infusion.
Here's the breakdown:
Primary Infusion:
Dextrose 5% in water (DSW) at 125 mL/hour (given) - This rate remains constant
throughout the secondary infusion.
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HESI RN DOSAGE CALCULATION IV EXAM WITH
QUESTIONS AND ANSWERS 2025-26 VERSION
Question 1:
The healthcare provider prescribes cefazolin 800 mg IM every 6 hours. The available vial
is labeled, "Cefazolin 1 gram," and the instructions for reconstitution state, "For IM use,
add 2.5 mL sterile water for injection to provide a total volume of 3.0 mL." How many mL
should the nurse administer? (Enter numerical value only. If rounding is required, round
to the nearest tenth.)
Explanation
Correct Answer (mL) : 2.4
Solution
Here's how to calculate the volume (mL) of the reconstituted cefazolin solution the nurse
should administer for each dose:
1. We know the following:
Prescribed dose: 800 mg cefazolin (given)
Vial information:
Contains 1 gram cefazolin (given) = 1000 mg (since 1 gram = 1000 milligrams)
Reconstituted with 2.5 mL sterile water for injection (given)
Yields a total volume of 3.0 mL (given)
2. We need to find the concentration of cefazolin (mg/mL) in the reconstituted solution.
3. Then, we can find the volume (mL) to administer for the prescribed dose (800 mg)
considering the concentration.
Steps:
a. Calculate the concentration after reconstitution:
Total volume after reconstitution = 3.0 mL (given)
Total amount of cefazolin after reconstitution = 1 gram (from the vial) = 1000 mg
Concentration (mg/mL) = Total amount of medication (mg) / Total volume after
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reconstitution (mL)
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Concentration (mg/mL) = 1000 mg / 3.0 mL
Concentration (mg/mL) = 333.33 mg/mL (round to one decimal place)
b. Calculate the volume to administer:
Volume to administer (mL) = Dose (mg) / Concentration (mg/mL)
Volume to administer (mL) = 800 mg / 333.33 mg/mL
Volume to administer (mL) = 2.4 mL (round to nearest tenth)
Therefore, the nurse should administer approximately 2.4 mL of the reconstituted
cefazolin solution intramuscularly every 6 hours.
Question 2:
The nurse is preparing a client's dose of an IM analgesic in a single syringe. The
prescription is hydromorphone 4 mg and hydroxyzine 25 mg. The
hydromorphone is available in a 10 mg/ml, ampule, and the hydroxyzine is
available in a 50 mg/ml, vial. How many total mL should the nurse administer?
(Enter the numeric value only. If rounding is required, round to the nearest tenth.)
Explanation
Correct Answer (mL) : 0.9
Solution
Here's how to calculate the total volume (mL) the nurse should administer for the
combined medication dose
1. Calculate the volume for each medication:
Hydromorphone:
Dose: 4 mg (given)
Concentration: 10 mg/mL (given)
Volume (mL) = Dose (mg) / Concentration (mg/mL)
Volume (mL) = 4 mg / 10 mg/mL
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Volume (mL) = 0.4 mL
Hydroxyzine:
Dose: 25 mg (given)
Concentration: 50 mg/mL (given)
Volume (mL) = Dose (mg) / Concentration (mg/mL)
Volume (mL) = 25 mg / 50 mg/mL
Volume (mL) = 0.5 mL
2. Add the volumes for each medication to find the total volume:
Total volume (mL) = Volume of hydromorphone (mL) + Volume of hydroxyzine (mL)
Total volume (mL) = 0.4 mL + 0.5 mL
Total volume (mL) = 0.9 mL (round to nearest tenth)
Therefore, the nurse should administer a total of 0.9 mL.
Question 3:
A client is receiving IV dextrose 5% in water (DSW) at 125 mL/hour and a secondary
infusion of pantoprazole 40 mg IV daily. The pharmacy provides a 110 mL premixed
solution of pantoprazole to be infused over 15 minutes. The nurse should program the
secondary infusion to deliver how many mL/hour? (Enter numeric value only.)
Explanation
Correct Answer (mL/hour) : 440
Solution
While the primary infusion rate (dextrose 5% in water) and the total volume of
pantoprazole solution are provided, the pantoprazole infusion doesn't directly affect the
rate of the primary DSW infusion.
Here's the breakdown:
Primary Infusion:
Dextrose 5% in water (DSW) at 125 mL/hour (given) - This rate remains constant
throughout the secondary infusion.
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