A nurse, via an infusion pump, sets up an infusion rate ratio of 2.75 mL/min for a continuous intravenous (IV) fluid for 7 hours.
What is the total volume of IV fluid being infused, in liters?

To find the milligrams per minute, you need to calculate the following:

- The volume of Lopressor in milliliters
- The infusion rate in milliliters per minute using the formula: Infusion rate (mL/min) = Total volume (mL) / Time (min)
- The dose of Lopressor in milligrams per minute using the formula: Dose (mg/min) = Infusion rate (mL/min) x Concentration (mg/mL)

First, divide the dose of Lopressor by the concentration to get the volume in milliliters:

5 mg / 1 mg/mL = 5 mL

Next, use the formula for infusion rate to find how many milliliters per minute the IV pump should deliver:

Infusion rate (mL/min) = Total volume (mL) / Time (min)

Since the total volume is 5 mL and the time is 2 minutes, plug in these values into the formula:

Infusion rate (mL/min) = 5 mL / 2 min

Simplify and solve for the infusion rate:

Infusion rate (mL/min) = 2.5 mL/min

Then, use the formula for dose to find how many milligrams per minute the patient should receive:

Dose (mg/min) = Infusion rate (mL/min) x Concentration (mg/mL)

Since the infusion rate is 2.5 mL/min and the concentration is 1 mg/mL, plug in these values into the formula:

Dose (mg/min) = 2.5 mL/min x 1 mg/mL

Simplify and solve for the dose:

Dose (mg/min) = 2.5 mg/min

Therefore, the patient should receive **2.5 mg/min** of Lopressor.

This answer is correct because BSA is the most accurate method for calculating the child's dose from the adult dose¹². BSA takes into account the child's weight and height, and reflects the physiological function and organ growth of the child beter than weight alone¹. BSA can be calculated using a nomogram or a formula based on the child's weight and height¹. The child's dose can then be calculated by multiplying the adult dose by the ratio of the child's BSA to the average adult BSA (1.73 m2)¹. For example:

Child dose by BSA = (mg/day) = Adult Dose in mg/day x BSA in m2 / 1.73

OR

Child dose by BSA = (mg/day) = Adult Dose in mg/m2 x BSA in m2

The other options are not correct because they are not accurate methods for calculating the child's dose from the adult dose. Actual body weight and ideal body weight may not account for individual variations in pharmacokinetics, pharmacodynamics, or clinical response. Actual body height is not a reliable indicator of drug dosage, as it does not reflect the body mass or organ function of the child.