A physician ordered magnesium sulfate 2 grams per hour for a maintenance dose. There are 40 grams of magnesium sulfate in 1 liter of lactated Ringers solution.
What is the rate per hour to administer the maintenance dose?

To set the IV pump correctly, you need to calculate the following:

• The patient's weight in kilograms
• The dose of Zofran in milligrams
• The infusion rate in milliliters per hour

First, convert the patient's weight from pounds to kilograms by dividing by 2.2:

176 lb / 2.2 = 80 kg

Next, multiply the patient's weight by the dose of Zofran per kilogram to get the total dose in milligrams:

80 kg x 0.15 mg/kg = 12 mg

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

Infusion rate (mL/h) = (Total volume (mL) x Flow factor (gt/mL)) / Time (min) x 60 min/h

Since the medication is mixed in 50 mL of normal saline and the infusion time is 15 minutes, plug in these values into the formula:

Infusion rate (mL/h) = (50 mL x 1 gt/mL) / 15 min x 60 min/h

Simplify and solve for the infusion rate:

Infusion rate (mL/h) = 200 mL/h

This numeric form is appropriate, according to the Joint Commission, because it does not use a trailing zero after a decimal point, which is a common cause of medication errors and should be avoided. A trailing zero may be misread or misinterpreted as a larger dose or omited altogether, resulting in a 10-fold overdose or underdose, respectively. For example, when prescriptions have been writen for "Coumadin 1.0 mg," patients have received 10 mg in error¹². Therefore, the Joint Commission requires that a trailing zero may be used only when required to demonstrate the level of precision of the value being reported, such as for laboratory results, imaging studies that report the size of lesions, or catheter/tube sizes. It may not be used in medication orders or other medication-related documentation.

The other options are not appropriate numeric forms because:

a) 3.0 uses a trailing zero after a decimal point, which poses a risk of confusion or error.

b) 0.30 uses a trailing zero after a decimal point, which poses a risk of confusion or error.

c) 0.03 is not equivalent to 0.3, as it is 10 times smaller.