The patient is receiving nitroglycerin 55 mcg/min.

Available: Nitroglycerin in 5% Dextrose Injection 25 mg per 250 mL (100 mcg/mL)

What is the flow rate?

A) 0.2 mg
The correct way to write the dosage is 0.2 mg. In pharmacology and medication administration, it is important to follow the guidelines set by the Institute for Safe Medication Practices (ISMP) and other standard bodies, which recommend that a leading zero be used before a decimal point. This helps to prevent errors in interpreting the dosage. Writing 0.2 mg clearly indicates two-tenths of a milligram, and the leading zero makes it easier to avoid misreading the dose as a whole number (2.0 mg) or omitting the decimal point entirely.

B) .2 mg
Writing the dosage as .2 mg (without the leading zero) is considered unsafe and is a poor practice. The absence of the leading zero before the decimal point increases the likelihood that the dose may be misread. For example, someone could confuse .2 mg with 2.0 mg or misinterpret it in a hurried situation, which could lead to a tenfold dosing error

C) 2.0 mg
Writing 2.0 mg would indicate two milligrams, which is not the correct dosage for "two-tenths of a milligram." While this format does use a decimal point, it does not represent the correct dose. This error could lead to an overdose if misread as a whole number.

D) 0.20 mg
While 0.20 mg is technically correct, it is not the preferred or necessary format. The use of two decimal places is unnecessary in this case. Since the dosage is two-tenths of a milligram, 0.2 mg is simpler and clearer. Using an unnecessary trailing zero (the second "0") can cause confusion or misinterpretation, especially in critical settings where every detail counts.

1. Convert patient weight from pounds to kilograms:

Patient weight (kg) = 152 lb x 0.453592 kg/lb = 68.94 kg

2. Calculate the desired dose in mcg/min:

Desired dose (mcg/min) = 5 mcg/kg/min x 68.94 kg = 344.7 mcg/min

3. Convert mcg/min to mg/min:

Desired dose (mg/min) = 344.7 mcg/min / 1000 mcg/mg = 0.3447 mg/min

4. Calculate the concentration of dobutamine in the solution:

Concentration (mg/mL) = 500 mg / 250 mL = 2 mg/mL

5. Calculate the flow rate in mL/min:

Flow rate (mL/min) = Desired dose (mg/min) / Concentration (mg/mL)

Flow rate (mL/min) = 0.3447 mg/min / 2 mg/mL = 0.17235 mL/min

6. Calculate the flow rate in mL/hr:

Flow rate (mL/hr) = 0.17235 mL/min x 60 min/hr = 10.341 mL/hr

7. Round to the nearest tenth:

Flow rate (mL/hr) = 10.3 mL/hr

Therefore, the correct answer is 10.4 mL/hr