Dosage Calculation RN Maternal Newborn Proctored Assessment 3.1 Questions With Complete Solutions

Dosage Calculation RN Maternal Newborn
Proctored Assessment 3.1 Questions With
Complete Solutions
Course

 Dosage Calculation RN Maternal Newborn

1. IV Infusion Rate Calculation

Question:
A nurse is preparing to administer lactated Ringer’s at 125 mL/hr to a postpartum client. The
IV tubing has a drop factor of 15 gtt/mL. Calculate the IV flow rate in gtt/min. (Round to the
nearest whole number.)

Solution:

Flow rate=(Volume per hour×Drop factor60)\text{Flow rate} = \left( \frac{\text{Volume per
hour} \times \text{Drop factor}}{60} \right)Flow rate=(60Volume per hour×Drop factor)
=(125×1560)=187560=31.25≈31 gtt/min= \left( \frac{125 \times 15}{60} \right) = \frac{1875}
{60} = 31.25 \approx 31 \, gtt/min=(60125×15)=601875=31.25≈31gtt/min

Rationale:
The IV flow rate is calculated to ensure the correct administration rate, preventing fluid overload
or underhydration.



2. Oxytocin Infusion Calculation

Question:
A nurse is preparing an oxytocin (Pitocin) IV infusion at 20 milliunits/min. The IV bag
contains 30 units in 500 mL of normal saline. Calculate the mL/hr rate. (Round to the nearest
whole number.)

Solution:
First, convert units to milliunits:

30 units=30,000 milliunits30 \text{ units} = 30,000 \text{ milliunits}30 units=30,000 milliunits

Find the concentration:

30,000 milliunits500 mL=60 milliunits/mL\frac{30,000 \text{ milliunits}}{500 \text{ mL}} =
60 \text{ milliunits/mL}500 mL30,000 milliunits=60 milliunits/mL

Now, calculate the mL/hr:

,(20 milliunits/min×6060 milliunits/mL)=120060=20 mL/hr\left( \frac{20 \text{ milliunits/min} \
times 60}{60 \text{ milliunits/mL}} \right) = \frac{1200}{60} = 20 \text{ mL/hr}
(60 milliunits/mL20 milliunits/min×60)=601200=20 mL/hr

Rationale:
Correct oxytocin dosing is crucial to prevent complications like uterine hyperstimulation or
fetal distress.



3. Magnesium Sulfate Infusion

Question:
A nurse is administering magnesium sulfate at 2 g/hr for preeclampsia. The IV bag contains 40
g in 1,000 mL of lactated Ringer’s. Calculate the mL/hr infusion rate.

Solution:
Find the concentration:

40g1000mL=0.04 g/mL\frac{40 g}{1000 mL} = 0.04 \text{ g/mL}1000mL40g=0.04 g/mL

Calculate the infusion rate:

2g/hr0.04g/mL=50 mL/hr\frac{2 g/hr}{0.04 g/mL} = 50 \text{ mL/hr}0.04g/mL2g/hr=50 mL/hr

Rationale:
Magnesium sulfate must be infused at the correct rate to prevent toxicity (respiratory
depression, loss of reflexes).



4. Heparin Infusion Calculation

Question:
A nurse is administering heparin at 18 units/kg/hr for a postpartum client. The client weighs 70
kg, and the IV bag contains 25,000 units in 500 mL. Calculate the mL/hr rate.

Solution:
Calculate total units per hour:

18×70=1260 units/hr18 \times 70 = 1260 \text{ units/hr}18×70=1260 units/hr

Find the concentration:

25,000 units500 mL=50 units/mL\frac{25,000 \text{ units}}{500 \text{ mL}} = 50 \
text{ units/mL}500 mL25,000 units=50 units/mL

,Calculate the rate:

126050=25.2≈25 mL/hr\frac{1260}{50} = 25.2 \approx 25 \text{ mL/hr}501260
=25.2≈25 mL/hr

Rationale:
Proper heparin dosing reduces the risk of clot formation while avoiding hemorrhage.



5. Acetaminophen (Tylenol) Dosage for Newborn

Question:
A neonate weighing 3.2 kg requires acetaminophen 15 mg/kg per dose. The concentration is
160 mg/5 mL. How many mL should the nurse administer per dose?

Solution:

15×3.2=48 mg15 \times 3.2 = 48 \text{ mg}15×3.2=48 mg

Calculate mL needed:

48 mg160 mg×5=1.5 mL\frac{48 \text{ mg}}{160 \text{ mg}} \times 5 = 1.5 \
text{ mL}160 mg48 mg×5=1.5 mL

Rationale:
Neonatal medication dosing is weight-based to prevent toxicity or underdosing.



6. Erythromycin Ophthalmic Ointment Dosage

Question:
The nurse is administering erythromycin 0.5% ophthalmic ointment to a newborn. The
prescribed dose is 1 cm per eye. The tube delivers 0.5 mg per cm. How many mg will the
newborn receive per dose?

Solution:

1 cm×2 eyes=2 cm1 \text{ cm} \times 2 \text{ eyes} = 2 \text{ cm}1 cm×2 eyes=2 cm
2 cm×0.5 mg/cm=1 mg2 \text{ cm} \times 0.5 \text{ mg/cm} = 1 \
text{ mg}2 cm×0.5 mg/cm=1 mg

Rationale:
Erythromycin prevents ophthalmia neonatorum (neonatal conjunctivitis).

, 7. Rho(D) Immune Globulin (RhoGAM) Dosage

Question:
A postpartum client is Rh-negative and requires RhoGAM 300 mcg IM within 72 hours of
delivery. The vial contains 300 mcg/2 mL. How many mL should the nurse administer?

Solution:

300 mcg300 mcg×2=2 mL\frac{300 \text{ mcg}}{300 \text{ mcg}} \times 2 = 2 \
text{ mL}300 mcg300 mcg×2=2 mL

Rationale:
RhoGAM prevents Rh isoimmunization, which can cause hemolytic disease in future
pregnancies.



8. Ampicillin Dosage for Neonatal Sepsis

Question:
A neonate weighing 2.5 kg requires ampicillin 50 mg/kg IV every 8 hours. The vial contains
500 mg in 10 mL. How many mL should the nurse administer per dose?

Solution:

50×2.5=125 mg50 \times 2.5 = 125 \text{ mg}50×2.5=125 mg 125500×10=2.5 mL\frac{125}
{500} \times 10 = 2.5 \text{ mL}500125×10=2.5 mL

Rationale:
Correct antibiotic dosing is critical to treat infections effectively while avoiding overdose.



9. Betamethasone IM Injection for Preterm Labor

Question:
A client in preterm labor is prescribed betamethasone 12 mg IM every 24 hours for 2 doses.
The vial contains 6 mg/mL. How many mL should the nurse administer per dose?

Solution:

126=2 mL\frac{12}{6} = 2 \text{ mL}612=2 mL