Nitroglycerin 125 mg diluted in 500 mL of D5W (dextrose 5% in water) is infusing at a rate of 42 mcg/minute for a patient with chest pain.
What rate (in mL/hr) should the nurse program into the IV pump to deliver this dose? Round your answer to the nearest tenth.
A.
6.5 mL/hr
B.
9.6 mL/hr
C.
10.1 mL/hr
D.
14.8 mL/hr
The correct answer and Explanation is :
To determine the correct infusion rate in mL/hr for delivering nitroglycerin at 42 mcg/minute, follow these steps:
- Calculate the total nitroglycerin concentration in the solution:
- The solution contains 125 mg of nitroglycerin diluted in 500 mL of D5W.
- Convert mg to mcg for easier calculations:
[
125 \text{ mg} = 125 \times 1000 \text{ mcg} = 125000 \text{ mcg}
] - The concentration of nitroglycerin in the solution is:
[
\frac{125000 \text{ mcg}}{500 \text{ mL}} = 250 \text{ mcg/mL}
]
- Determine the total nitroglycerin delivered per minute:
- The infusion rate is 42 mcg/minute.
- Calculate the infusion rate in mL/minute:
- To find out how many mL/minute are needed to deliver 42 mcg/minute, use the concentration calculated:
[
\text{Infusion rate (mL/minute)} = \frac{\text{Dose rate (mcg/minute)}}{\text{Concentration (mcg/mL)}} = \frac{42 \text{ mcg/minute}}{250 \text{ mcg/mL}} = 0.168 \text{ mL/minute}
]
- Convert the infusion rate from mL/minute to mL/hour:
- There are 60 minutes in an hour, so:
[
\text{Infusion rate (mL/hour)} = 0.168 \text{ mL/minute} \times 60 \text{ minutes/hour} = 10.08 \text{ mL/hour}
] - Rounding 10.08 to the nearest tenth gives 10.1 mL/hr.
Therefore, the correct infusion rate to program into the IV pump is 10.1 mL/hr.
Explanation:
To ensure accurate medication delivery, it’s crucial to first determine the concentration of the drug in the infusion solution. Here, nitroglycerin was provided as 125 mg in 500 mL, translating to 250 mcg/mL. The dose rate (42 mcg/min) must be converted into a volume rate that matches the concentration, resulting in an infusion rate of 0.168 mL/min. By converting this rate to mL/hr, you get 10.1 mL/hr. Accurate calculations ensure the correct medication dosage and optimal patient care.