For problems involving adult patients, the answer will be rounded to the nearest tenth. Although some IV pumps do not allow calibration to the tenth or hundredth, for the purpose of this exam, IV rate calculations will be rounded to the nearest whole drop (gt/min) or to the nearest whole number IV (ml/hr). To promote safety, a zero must be placed to the left of the decimal point in answers that are less than one. No zero is allowed to the right of the decimal point in answers that are whole numbers. For example, 0.5 mg must be answered as 0.5 mg and 5.0 mg must be answered as 5 mg.
The physician orders: Magnesium 4 gms loading dose to infuse over 30 minutes at 0500. Then infuse a maintenance dose of 1 gram /hr. The pharmacy sends 80 Gms in 1000 mL of LR. What would the nurse set the pump for the loading dose at 5 Am? Be sure to enter the number AND the unit of measurement (mL). Partial credit will not be given.
The correct answer and Explanation is :
To solve the problem, we need to calculate the infusion rate for the loading dose of Magnesium. Here’s how to approach it:
Given Data:
- Loading Dose: 4 grams
- Infusion Time for Loading Dose: 30 minutes
- Total Solution Provided: 80 grams in 1000 mL of LR
- Starting Time of Infusion: 0500
Calculation:
- Determine the concentration of the solution:
The total solution contains 80 grams of Magnesium in 1000 mL. Thus, the concentration is:
[
\text{Concentration} = \frac{80 \text{ grams}}{1000 \text{ mL}} = 0.08 \text{ grams/mL}
] - Calculate the volume needed for the loading dose:
We need to infuse 4 grams of Magnesium. Using the concentration calculated:
[
\text{Volume required} = \frac{\text{Desired dose}}{\text{Concentration}} = \frac{4 \text{ grams}}{0.08 \text{ grams/mL}} = 50 \text{ mL}
] - Determine the infusion rate for the loading dose:
The loading dose needs to be infused over 30 minutes. Therefore, the infusion rate in mL/hr is:
[
\text{Infusion rate} = \frac{\text{Volume required}}{\text{Infusion time (hours)}} = \frac{50 \text{ mL}}{0.5 \text{ hours}} = 100 \text{ mL/hr}
]
Answer:
To deliver the loading dose of 4 grams over 30 minutes, the nurse should set the IV pump to 100 mL/hr.
Explanation:
Infusion calculations involve determining the amount of medication required and translating that into a practical infusion rate. In this scenario, understanding the concentration of the solution allowed for accurate calculation of the volume needed to deliver the correct dose. Once the required volume was identified, converting this into an hourly rate ensures that the medication is administered within the desired timeframe. This ensures safe and effective treatment administration, aligning with the physician’s orders for precise dosing.