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NurseDive Free Nursing Practice Question
The package insert instructs reconstituting with 3.4 mL of sterile water to yield nafcillin 250 mg/mL. How many mL should the nurse administer?
(Round the answer to the nearest whole number. Use a leading zero if it applies. Do not use a trailing zero.)
This question is an excerpt from Nurse Dive's nursing test bank - ATI RN Dosage Calculation Proctored Exam. Take the full exam now
Full Explanation
Step 1 is to determine the amount of medication in 1 mL after reconstitution. This is calculated by dividing the total available medication (1000 mg) by the total volume after reconstitution (3.4 mL):
1000 mg ÷ 3.4 mL = 294.12 mg/mL
Step 2 is to determine how many mL are needed to obtain 500 mg. This is done by dividing the required dose (500 mg) by the concentration (294.12 mg/mL):
500 mg ÷ 294.12 mg/mL = 1.7 mL
Rounding to the nearest whole number, the correct amount to administer is 2 mL.
Similar Questions
A nurse is preparing to administer cefazolin 250 mg via intermittent IV bolus every 8 hr. Available is cefazolin 500 mg vial.
The package insert instructs to add 2 mL of sterile water to yield a concentration of 225 mg/mL and then add to 50 mL of 0.9% sodium chloride.
How many mL of cefazolin should the nurse add to the 50 mL of 0.9% sodium chloride? (Round the answer to the nearest tenth.
Use a leading zero if it applies.
Do not use a trailing zero.). mL. .
Full Explanation
Step 1: Calculate the volume of cefazolin needed for a 250 mg dose.
Volume of cefazolin = 250 mg ÷ 225 mg/mL = 1.11 mLStep 2: Round the answer to the nearest tenth.
1.11 mL rounded to the nearest tenth is 1.1 mL.Therefore, the nurse should add 1.1 mL of cefazolin to the 50 mL of 0.9% sodium chloride.
A nurse is preparing to administer gentamicin 5 mg/kg via intermittent IV bolus to a client who weighs 210 lb. The amount available is gentamicin 10 mg/mL. How many mL should the nurse administer?
(Round the answer to the nearest whole number. Use a leading zero if it applies. Do not use a trailing zero.)
Full Explanation
Step 1 is to convert the client’s weight from pounds to kilograms since the medication dosage is prescribed in mg/kg. Given that 1 kg is approximately 2.2 lb, the conversion is:
210 lb ÷ 2.2 = 95.45 kg (rounded to the nearest hundredth).
Step 2 is to calculate the total amount of medication needed using the formula:
Dose (mg/kg) × Weight (kg) = Total medication needed (mg)
5 mg/kg × 95.45 kg = 477.27 mg (rounded to the nearest hundredth).
Step 3 is to calculate the volume to administer using the formula:
Total medication needed (mg) ÷ Concentration (mg/mL) = Volume to administer (mL)
477.27 mg ÷ 10 mg/mL = 47.73 mL
Rounding off to the nearest whole number, the nurse should administer 48 mL of gentamicin.
A nurse is preparing to administer oxymorphone 1.5 mg IM to a client.
Available is oxymorphone 1 mg/mL. How many mL should the nurse administer?
(Round the answer to the nearest tenth. Use a leading zero if it applies. Do not use a trailing zero.)
Full Explanation
Step 1 is to calculate the volume to administer using the formula:
Dose (mg) ÷ Concentration (mg/mL)
Given that the prescribed dose is 1.5 mg and the available concentration is 1 mg/mL, we calculate:
1.5 mg ÷ 1 mg/mL = 1.5 mL
Since the result is already rounded to the nearest tenth, the nurse should administer 1.5 mL of oxymorphone.