Question

A client with neuroleptic malignant syndrome receives a prescription for dantrolene 1.5 mg/kg IV. The client weighs 198 pounds. The label on 250 mg vial reads, "Reconstitute with 5 mL sterile water for injection, USP. Reconstitution yields 50 mg/mL." How many mg should the nurse administer? (Enter numeric value only.)

Answer 1

Correct Answers:

135

Rationale :

💉The client weighs 198 lb, which converts to 90 kg (198 ÷ 2.2 = 90).

🧪The prescribed dose is 1.5 mg/kg, so 90 × 1.5 = 135 mg.

📦The concentration per mL is not needed here since only the dose in mg was requested.

📏This confirms the correct weight-based dosage calculation in milligrams.

📌Core Message

Convert weight to kg, multiply by mg/kg dose to find total medication in mg.

Answer 2

Correct Answers:

0.5

Rationale :

⚖️132 lb = 60 kg (132 ÷ 2.2 = 60).

🧮60 kg × 5 mcg = 300 mcg total dose.

💉Available: 480 mcg in 0.8 mL → 300 ÷ 480 = 0.625 × 0.8 = 0.5 mL (rounded to nearest tenth).

📏This ensures precise SUBQ volume using ratio and correct unit conversion.

📌Core Message

Calculate mcg from weight, convert using concentration, and round to find accurate mL dose.

Answer 3

Correct Answers:

3

Rationale :

💉The dose is 1,800,000 units; the syringe provides 1,200,000 units in 2 mL.

🧪Set a ratio: (1,800,000 ÷ 1,200,000) = 1.5 → 2 mL × 1.5 = 3 mL.

📦This conversion ensures the nurse administers the full prescribed dose.

📏Rounding to the nearest whole number is appropriate here.

📌Core Message

Use unit-to-volume ratio to determine mL for full ordered dose.

Answer 4

Correct Answers:

4.7

Rationale :

📏Concentration = 30 mg/mL.

💉Required: 140 mg ÷ 30 mg/mL = 4.666..., rounded to 4.7 mL.

🧪Using the exact concentration allows accurate volume calculation for pediatric dosing.

⚠️Precise dosing is essential to treat CNS infections like meningitis.

📌Core Message

Divide ordered dose by solution concentration to get exact mL for administration.

Answer 5

Correct Answers:

2.4

Rationale :

📦0.6 mg = 600 mcg.

💉Concentration: 500 mcg in 2 mL → 600 ÷ 500 = 1.2 × 2 = 2.4 mL.

🧪Unit conversions from mg to mcg are required for this type of vial concentration.

📏This ensures accuracy when administering IV cardiac medications.

📌Core Message

Convert mg to mcg, apply concentration ratio, and round to find correct volume in mL.

Answer 6

Correct Answers:

0.9

Rationale :

💉Hydromorphone: 4 mg ÷ 10 mg/mL = 0.4 mL.

🧪Hydroxyzine: 25 mg ÷ 50 mg/mL = 0.5 mL.

📦Total volume = 0.4 + 0.5 = 0.9 mL.

📏Combining two drugs in one syringe requires precise individual dose conversions.

📌Core Message

Calculate each individual dose volume, then add to find total mL to administer.

Answer 7

Correct Answers:

7.5

Rationale :

📦750 mg reconstituted in 100 mL → 750 ÷ 100 = 7.5 mg/mL.

🧪This is a straight division of total drug amount by volume.

📏Knowing the final concentration helps in verifying administration accuracy.

⚠️Always confirm with label after reconstitution to ensure correct drug delivery.

📌Core Message

Divide total drug amount by diluent volume to find mg/mL concentration.

Answer 8

Correct Answers:

6

Rationale :

💧20 units in 1000 mL = 0.02 units/mL.

🧮Desired: 2 milliunits/min = 0.002 units/min.

📏0.002 ÷ 0.02 = 0.1 mL/min × 60 = 6 mL/hr.

⚠️Precise conversion between units and mL is critical with oxytocin titration.

📌Core Message

Convert unit concentration, divide desired rate, then multiply to find mL/hr infusion rate.

Answer 9

Correct Answers:

20

Rationale :

📦50 units in 100 mL → 0.5 units/mL.

🧮10 units/hour ÷ 0.5 units/mL = 20 mL/hr.

📏Using unit-to-volume ratio ensures proper insulin infusion rate.

⚠️Precision prevents hypoglycemia or underdosing in DKA management.

📌Core Message

Use unit concentration to calculate volume/hour for infusion pump settings.

Answer 10

Correct Answers:

3

Rationale :

📦120 mg ÷ 40 mg/min = 3 minutes.

🧪Dividing total dose by rate gives safe administration time.

📏Following manufacturer’s rate prevents adverse reactions.

⚠️Too rapid administration of furosemide can cause ototoxicity.

📌Core Message

Divide total dose by rate of administration to get correct duration in minutes.

HESI RN Dosage Calculation 2025 Exam-1

No.

8 :
A client receives a prescription for oxytocin 2 milliunits/min intravenously (IV) for labor augmentation. The IV bag contains oxytocin 20 units in lactated Ringer's 1 liter. How many mL/hour should the nurse program the infusion pump to deliver? (Enter numerical value only.)

9 :
The pharmacy delivers an IV infusion of sodium chloride 100 mL with regular insulin 50 units for a client in diabetic ketoacidosis. The prescription rate is 10 units/hour. How many mL/hour should the nurse program the infusion pump? (Enter numeric value only.)

HESI RN Dosage Calculation 2025 Exam-1

No.

8 : A client receives a prescription for oxytocin 2 milliunits/min intravenously (IV) for labor augmentation. The IV bag contains oxytocin 20 units in lactated Ringer's 1 liter. How many mL/hour should the nurse program the infusion pump to deliver? (Enter numerical value only.)

9 : The pharmacy delivers an IV infusion of sodium chloride 100 mL with regular insulin 50 units for a client in diabetic ketoacidosis. The prescription rate is 10 units/hour. How many mL/hour should the nurse program the infusion pump? (Enter numeric value only.)

8 :
A client receives a prescription for oxytocin 2 milliunits/min intravenously (IV) for labor augmentation. The IV bag contains oxytocin 20 units in lactated Ringer's 1 liter. How many mL/hour should the nurse program the infusion pump to deliver? (Enter numerical value only.)

9 :
The pharmacy delivers an IV infusion of sodium chloride 100 mL with regular insulin 50 units for a client in diabetic ketoacidosis. The prescription rate is 10 units/hour. How many mL/hour should the nurse program the infusion pump? (Enter numeric value only.)