A triage nurse in the obstetrical unit is preparing to administer a magnesium sulfate bolu… — NCLEX-RN

A triage nurse in the obstetrical unit is preparing to administer a magnesium sulfate bolus to a gravid client admitted with severe preeclampsia. The provider orders a loading dose of $4 \text{ g}$ of magnesium sulfate to be infused intravenously over $20 \text{ minutes}$ . The medication is supplied by the pharmacy as a premixed $500 \text{ mL}$ bag of 0.9% normal saline containing $20 \text{ g}$ of magnesium sulfate. What should the nurse set the intravenous infusion pump rate to in $\text{mL/hr}$ ? Record your answer as a whole number.

Answer: 300 mL/hr

Answer

300

The correct pump setting is

300 \text{ mL/hr}

. The nurse first determines that the prescribed

4 \text{ g}

dose is contained in

100 \text{ mL}

of the supplied solution. Because this

100 \text{ mL}

volume must infuse over

20 \text{ minutes}

, the nurse calculates the hourly rate by dividing the volume by the time in minutes and multiplying by 60 minutes per hour (

100 / 20 \times 60 = 300

Step-by-Step Solution

Identify the total volume and total mass of the supplied medication to find the concentration.

There are

20 \text{ g}

500 \text{ mL}

, which simplifies to

1 \text{ g}

of magnesium sulfate per

25 \text{ mL}

of fluid.

This determines how many mL of the IV fluid contain the prescribed loading dose.

Calculate the volume needed for the prescribed loading dose of

4 \text{ g}

4 \text{ g} \times 25 \text{ mL/g} = 100 \text{ mL}

This is the total volume of fluid that must be infused to deliver exactly

4 \text{ g}

of the medication to the client.

Convert the infusion time from minutes to hours to determine the IV pump setting.

The target is

100 \text{ mL}

to be infused in

20 \text{ minutes}

. To find the hourly rate:

(100 \text{ mL} / 20 \text{ minutes}) \times 60 \text{ minutes/hr} = 300 \text{ mL/hr}

Intravenous infusion pumps must be programmed in

\text{mL/hr}

Key Concept

Intravenous Medication Calculations for High-Risk Obstetrics

Estimated Time:2m 0s

Question

Answer

Step-by-Step Solution

Key Concept

Common Mistakes

Topics

More questions from this topic