What is the dosage in milligrams per hour for an order to infuse morphine 200 mg in 250 mL dextrose 5% in water at 16 mL/h? Record your answer as a whole number. mg/h
The correct answer and explanation is:
Correct Answer: 13 mg/h
Explanation (300 Words)
To calculate the dosage in milligrams per hour (mg/h), we need to determine how many milligrams of morphine are delivered in each milliliter of solution and then multiply that by the infusion rate.
Step 1: Find the concentration of morphine (mg/mL)
You’re given that the IV bag contains:
- 200 mg of morphine
- In 250 mL of D5W (Dextrose 5% in Water)
Concentration=200 mg250 mL=0.8 mg/mL\text{Concentration} = \frac{200 \text{ mg}}{250 \text{ mL}} = 0.8 \text{ mg/mL}
So each milliliter of the IV fluid contains 0.8 mg of morphine.
Step 2: Multiply concentration by infusion rate
The infusion rate is:
- 16 mL/hour
Now multiply the rate by the concentration: Dosage (mg/h)=0.8 mg/mL×16 mL/h=12.8 mg/h\text{Dosage (mg/h)} = 0.8 \text{ mg/mL} \times 16 \text{ mL/h} = 12.8 \text{ mg/h}
Since the question asks you to record your answer as a whole number, we round 12.8 mg/h to the nearest whole number, which is: 13 mg/h\boxed{13 \text{ mg/h}}
Summary
This type of calculation is essential in nursing, pharmacy, and medical practice to ensure patient safety and accurate drug delivery. Always:
- Determine the concentration (mg/mL),
- Use the infusion rate (mL/h),
- Multiply to get mg/h,
- Round only if instructed (as in this case).
Accurate dosage calculations help prevent underdosing (ineffective treatment) or overdosing (potential toxicity), especially for potent drugs like morphine.