Iowa Public Television

Challenge Question Number 1 for Director of Pharmacy #1174

Clearly describe what you expect from the students:
A patient in the critical care unit has an order to receive dopamine by continuous infusion at a rate of 8 mcg/kg/min. I need to mix a suitable solution for IV use, and calculate a drip rate in ml/hr to allow the nurses to run the medication at the proper rate.

Additional Information: Dopamine is packaged in 200 mg ampules. We normally mix 500 ml at a time. The patient weighs 180 pounds.

In order to give the teacher some guidance in evaluating the student's project(s); list some tips that may help to assess the student's work:
Tips: Convert the patient's weight to kg.
Calculate the total dopamine needs for 1 hour.
Convert that total mcg to mg.
Calculate how many ml of solution are needed to achieve that mg dose, based on how the solution was mixed. We normally use 400 mg dopamine in 500 ml IV solution.

The correct answer is 49 ml/hr when mixed 400 mg dopamine in 500 Normal Saline.

(180 lbs. / 2.2 lbs/kg = 82 kg)
(82 kg x 8 mcg/kg/min x 60 min=39,360 mcg/hr or 39.36 mg/hr)
By simple proportion, if 500 ml contains 400 mg, then how many ml contains 39.39 mg? (39.36 mg x 500 ml/400 = 49.2 ml)
Answer = 49 ml