A client is admitted to the cardiac intensive care unit with acute decompensated heart fai… — NCLEX-RN

A client is admitted to the cardiac intensive care unit with acute decompensated heart failure and a severely elevated blood pressure. The client is receiving a continuous intravenous (IV) infusion of nitroglycerin currently running at $15\text{ mcg/min}$ . The provider's prescription states: "Titrate nitroglycerin infusion upward by $5\text{ mcg/min}$ every 5 minutes until systolic blood pressure is less than $140\text{ mm Hg}$ ." The pharmacy provides a premixed nitroglycerin solution of $50\text{ mg}$ in $250\text{ mL}$ of $5\%$ dextrose in water (D5W). The client's blood pressure remains elevated, requiring exactly two dosage titrations over the next 10 minutes. What will the nurse set the IV infusion pump rate to in $\text{mL/hr}$ following the second titration? Record your answer as a number with one decimal place.

Answer: 7.5 mL/hr

Answer

7.5

To solve this problem, multiple mathematical conversions are required to determine the final pump settings. First, determine the new dose: two titrations of

5\text{ mcg/min}

added to the baseline of

15\text{ mcg/min}

equals

25\text{ mcg/min}

. Next, convert this to an hourly rate because IV pumps run in mL/hr:

25\text{ mcg/min} \times 60\text{ min/hr} = 1,500\text{ mcg/hr}

. Then, determine the concentration of the supplied medication. Convert

50\text{ mg}

50,000\text{ mcg}

so the units match the prescription, and divide by the total bag volume of

250\text{ mL}

to find the concentration is

200\text{ mcg/mL}

. Finally, divide the required hourly dose (

1,500\text{ mcg/hr}

) by the concentration (

200\text{ mcg/mL}

) to determine the correct IV pump rate of

7.5\text{ mL/hr}

Step-by-Step Solution

Calculate the new ordered dose after the required titrations.

25\text{ mcg/min}

The rate starts at 15 mcg/min and increases by 5 mcg/min twice (total increase of 10 mcg/min).

Convert the new per-minute dosage to a per-hour dosage.

1,500\text{ mcg/hr}

IV infusion pumps are set in mL/hr, so the dose must reflect an hourly rate (

25 \times 60

Convert the medication mass in the IV bag from milligrams to micrograms.

50,000\text{ mcg}

The ordered dose is in micrograms, so the available medication must be in the same unit (

50 \times 1,000

Determine the concentration of the nitroglycerin solution in mcg/mL.

200\text{ mcg/mL}

Dividing the total micrograms (

50,000

) by the total volume (

250\text{ mL}

) gives the concentration.

Calculate the final IV pump rate in mL/hr.

7.5\text{ mL/hr}

Dividing the required hourly dose (

1,500\text{ mcg/hr}

) by the concentration (

200\text{ mcg/mL}

) yields the volume needed per hour.

Key Concept

Continuous IV Infusion Titration and Weight-Independent Dose Calculations

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