A nurse is preparing to administer methylprednisolone 30 mg/kg via IV bolus to a client who weighs 184 lb. Available is methylprednisolone 125 mg/mL. How many mL should the nurse administer? (Round the answer to the nearest tenth. Use a leading zero if it applies. Do not use a trailing zero.)
The Correct answer and Explanation is:
To determine the correct volume of methylprednisolone to administer, we first need to calculate the total dose in milligrams based on the client’s weight and the ordered dosage.
- Convert the client’s weight from pounds to kilograms:
[
\text{Weight in kg} = \frac{\text{Weight in lb}}{2.2} = \frac{184 \, \text{lb}}{2.2} \approx 83.6 \, \text{kg}
] - Calculate the required dose in milligrams:
The order is for 30 mg/kg. Therefore:
[
\text{Total dose (mg)} = 30 \, \text{mg/kg} \times 83.6 \, \text{kg} \approx 2508 \, \text{mg}
] - Determine the volume of methylprednisolone needed:
The available concentration of methylprednisolone is 125 mg/mL. To find out how many mL are needed to achieve the total dose, we use the formula:
[
\text{Volume (mL)} = \frac{\text{Total dose (mg)}}{\text{Concentration (mg/mL)}} = \frac{2508 \, \text{mg}}{125 \, \text{mg/mL}} \approx 20.064 \, \text{mL}
] - Round to the nearest tenth:
When rounding 20.064 mL to the nearest tenth, we get 20.1 mL.
Therefore, the nurse should administer 20.1 mL of methylprednisolone.
Explanation
In this calculation, it’s crucial to convert the weight from pounds to kilograms as medical dosages are typically calculated in metric units. The total dose is then determined by multiplying the weight in kilograms by the prescribed dosage in mg/kg. This method ensures accurate dosing, which is vital in preventing underdosing or overdosing, both of which can lead to significant health complications.
Using the concentration of the medication available (125 mg/mL), we then calculate the required volume to achieve the total dose. Finally, rounding off the volume to the appropriate decimal place is standard practice in clinical settings to maintain precision and prevent errors in administration. The calculation follows a systematic approach, ensuring that each step is clear and logical, ultimately prioritizing patient safety.