Dopamine is prescribed at 5 mcg/kg/min. The client weighs 178 pounds. The label reads dopamine 800 mg in 500 mL of D5W. How many mL per hour should be administered? (Round to the nearest whole number)

Dopamine is prescribed at 5 mcg/kg/min. The client weighs 178 pounds. The label reads dopamine 800 mg in 500 mL of D5W. How many mL per hour should be administered? (Round to the nearest whole number)

• A. 10 mL/hr
• B. 15 mL/hr
• C. 20 mL/hr
• D. 25 mL/hr

Answer: (B)

Determining the IV infusion rate from a weight-based dose and a stock solution concentration. First convert the patient’s weight to kilograms: 178 lb ÷ 2.2046 ≈ 80.7 kg. At 5 mcg/kg/min, the dose per minute is 80.7 × 5 ≈ 403.5 mcg/min, which is 0.4035 mg/min. Over one hour, that’s 0.4035 mg/min × 60 ≈ 24.2 mg/hour. Next, use the stock concentration: 800 mg in 500 mL is 800/500 = 1.6 mg/mL. To deliver 24.2 mg/hour, the required volume per hour is 24.2 mg/hour ÷ 1.6 mg/mL ≈ 15.1 mL/hour. Rounded to the nearest whole number, the rate is 15 mL/hour.

Determining the IV infusion rate from a weight-based dose and a stock solution concentration.

First convert the patient’s weight to kilograms: 178 lb ÷ 2.2046 ≈ 80.7 kg. At 5 mcg/kg/min, the dose per minute is 80.7 × 5 ≈ 403.5 mcg/min, which is 0.4035 mg/min. Over one hour, that’s 0.4035 mg/min × 60 ≈ 24.2 mg/hour.

Next, use the stock concentration: 800 mg in 500 mL is 800/500 = 1.6 mg/mL. To deliver 24.2 mg/hour, the required volume per hour is 24.2 mg/hour ÷ 1.6 mg/mL ≈ 15.1 mL/hour. Rounded to the nearest whole number, the rate is 15 mL/hour.