A nurse is preparing to administer enoxaparin 1 mg/kg subcutaneous to a client who weighs 165 lb. Available is enoxaparin 30 mg/0.3 mL. How many ml should the nurse administer per dose? (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 dosage of enoxaparin to administer, follow these steps:
- Convert the client’s weight from pounds to kilograms.
- The weight in pounds (lb) is 165 lb.
- Conversion factor: 1 lb = 0.453592 kg.
- Weight in kg = 165 lb × 0.453592 kg/lb = 74.84 kg (rounded to two decimal places).
- Calculate the total dose of enoxaparin needed.
- The prescribed dose is 1 mg/kg.
- Dose (mg) = Weight (kg) × Dose (mg/kg) = 74.84 kg × 1 mg/kg = 74.84 mg.
- Determine the volume of enoxaparin solution required.
- Available concentration: 30 mg per 0.3 mL.
- This means 1 mL of the solution contains 30 mg of enoxaparin.
- To find the volume needed for 74.84 mg, use the formula: Volume (mL)=Desired Dose (mg)Concentration (mg/mL)\text{Volume (mL)} = \frac{\text{Desired Dose (mg)}}{\text{Concentration (mg/mL)}}Volume (mL)=Concentration (mg/mL)Desired Dose (mg) Volume (mL)=74.84 mg30 mg0.3 mL=74.84 mg100 mg/mL=0.7484 mL\text{Volume (mL)} = \frac{74.84 \text{ mg}}{\frac{30 \text{ mg}}{0.3 \text{ mL}}} = \frac{74.84 \text{ mg}}{100 \text{ mg/mL}} = 0.7484 \text{ mL}Volume (mL)=0.3 mL30 mg74.84 mg=100 mg/mL74.84 mg=0.7484 mL
- Round the final volume to the nearest tenth.
- Volume = 0.7484 mL.
- Rounded to the nearest tenth: 0.7 mL.
Answer: The nurse should administer 0.7 mL of enoxaparin per dose.
Explanation:
To ensure proper dosing, it’s crucial to convert the client’s weight to kilograms as medication dosages are often based on weight in kilograms. Next, calculate the total amount of medication required by multiplying the client’s weight by the dose per kilogram.
In this case, the weight in kilograms is used to determine that the client requires 74.84 mg of enoxaparin. Knowing the concentration of the available solution helps to calculate how much volume of the solution is needed to provide this dose.
The concentration provided (30 mg per 0.3 mL) allows you to determine that 1 mL of solution contains 100 mg of enoxaparin. Dividing the required dose by this concentration yields the volume of solution needed. After calculating and rounding to the nearest tenth, you get 0.7 mL.
This step-by-step approach ensures accurate administration of the medication, minimizing the risk of underdosing or overdosing.