A client who weighs 65 kg receives a prescription for lorazepam 44 mcg/kg intravenously to be administered 20 minutes before a scheduled procedure. The medication is available in 2 mg/mL vial. How many mL should the nurse administer? (Enter numerical value only. If rounding is required, round to the nearest tenth.)
The Correct Answer and Explanation is:
To determine how many mL of lorazepam should be administered, follow these steps:
- Calculate the total dose required: The prescription is for 44 mcg/kg, and the client weighs 65 kg. Therefore, the total dose in micrograms (mcg) is: [
\text{Total Dose (mcg)} = \text{Dose per kg} \times \text{Weight} = 44 \text{ mcg/kg} \times 65 \text{ kg}
] [
\text{Total Dose (mcg)} = 2860 \text{ mcg}
] - Convert the dose from micrograms to milligrams: There are 1000 micrograms in a milligram. Thus: [
\text{Total Dose (mg)} = \frac{2860 \text{ mcg}}{1000 \text{ mcg/mg}} = 2.86 \text{ mg}
] - Determine the volume of the medication required: The medication is available in a concentration of 2 mg/mL. To find the volume in mL, use the formula: [
\text{Volume (mL)} = \frac{\text{Total Dose (mg)}}{\text{Concentration (mg/mL)}}
] Substituting the known values: [
\text{Volume (mL)} = \frac{2.86 \text{ mg}}{2 \text{ mg/mL}} = 1.43 \text{ mL}
] Rounding to the nearest tenth: [
\text{Volume (mL)} \approx 1.4 \text{ mL}
]
Therefore, the nurse should administer 1.4 mL of lorazepam.
Explanation:
- Dose Calculation: The initial step involves determining the total dosage of lorazepam based on the client’s weight and the prescribed dosage per kilogram. This calculation helps to ensure that the amount administered is appropriate for the client’s body weight.
- Unit Conversion: Converting the dosage from micrograms to milligrams is necessary because the medication concentration is provided in milligrams per milliliter. This step simplifies the calculation of how much liquid medication is needed.
- Volume Calculation: Using the concentration of the medication, we calculate how many milliliters of the solution are required to achieve the prescribed dosage. This ensures accurate delivery of the medication.
By following these steps, we ensure that the correct dose is administered, adhering to the prescription and minimizing the risk of medication errors.