HESI RN
RN Hesi Med Surg Dosage Calculations Questions
Extract:
Question 1 of 5
The nurse is preparing to administer methylprednisolone 40 mg IV. The medication vial is labeled '125 mg per 2 mL.' How many mL of medication should the nurse administer? (Enter numeric value only. If rounding is required, round to the nearest hundredth.)
Correct Answer: 0.64
Rationale: Concentration: 125 mg / 2 mL = 62.5 mg/mL. Volume = 40 / 62.5 = 0.64 mL.
Question 2 of 5
An adult client receives a prescription for diphenhydramine 15 mL by mouth every 12 hours PRN for pruritus. The bottle is labeled, diphenhydramine 12.5 mg/5 mL. What is the total daily dose in mg that the client receives? (Enter numerical value only.)
Correct Answer: 75
Rationale:
To find the total daily dose, calculate the mg per dose: 12.5 mg/5 mL means 15 mL contains (12.5 × 15) / 5 = 37.5 mg. The prescription allows two doses daily (every 12 hours PRN), so 37.5 × 2 = 75 mg/day.
Question 3 of 5
Filgrastim 5 mcg/kg/day subcutaneous is prescribed for a child with cancer who weighs 88 pounds. The medication is labeled 300 mcg/mL. How many mL should the nurse administer daily to this child? (Enter the numerical value only. If rounding is required, round to the nearest tenth.)
Correct Answer: 0.7
Rationale: Weight: 88 × 0.454 = 39.952 kg. Dose: 5 mcg/kg/day × 39.952 = 199.76 mcg/day. Volume: 199.76 / 300 = 0.66587 mL, rounded to 0.7 mL.
Question 4 of 5
Penicillin G procaine 240,000 units Intramuscularly is prescribed for a 4-year-old child who has a streptococcal respiratory Infection. The medication vial is labeled 1,200,000 units/2 mL. How many ml. should the nurse administer? (Enter numeric value only. If rounding is required, round to the nearest tenth.)
Correct Answer: 0.4
Rationale: Concentration: 1,200,000 units / 2 mL = 600,000 units/mL. Volume = 240,000 / 600,000 = 0.4 mL.
Question 5 of 5
A pediatric client with cerebral palsy receives a prescription for a 75% enteral nutrition formula of 320 mL to infuse at 80 mL/hour via an enteral feeding pump. The formula is available full strength in a 240 mL can. To prepare the solution, the nurse should use how many mL of the enteral nutrition formula? (Enter numeric value only. If rounding is required, round to the nearest whole number.)
Correct Answer: 192
Rationale: For a 75% solution, let x = formula volume, y = water. x + y = 320 mL, x / 320 = 0.75. Solving, x = 0.75 × 320 = 240 mL formula, but adjusted for dilution: x = (3/2) y, x + y = 320, yields x = 192 mL formula.