How to Calculate Dopamine Infusions

Dopamine Infusion Calculations Review

Before beginning dopamine infusion calculations, let’s review a couple of numbers that we work with in the metric system. There are 1000 micrograms in 1 milligram. There are 1000 milligrams in 1 gram. Grams, milligrams, and micrograms are in multiples of a thousand. Remember those for the calculations.

Related Video – Dopamine – ACLS Drugs

Calculation

In most cases, the starting dose of dopamine is 5 mcg/kg/min.

Here is an example of a patient weighing 86 kg. Say you want to give 5 mcg/kg/min. First, divide that over the concentration. Next, multiply 5 mcg times 86 kg times 60 seconds. The 60 seconds is the per-minute part. Then, divide the numerator by the concentration, which in this case is 1600 mcg/mL. The answer is 16.125 mL/hour on the IV pump, which incidentally is exactly the same as drops per minute of 60-drop tubing.

Example dopamine calculation for a patient weighing 86 kg.

Let’s examine the details of the calculation. First, calculate the concentration. When examining the package of dopamine, it says there is 400 mg of dopamine in 250 mL. To get the concentration, take 400 divided by 250. That is going to give a concentration of 1.6 milligrams per mL.

However, we are not dosing in mg. We’re dosing in mcg. How many mcgs in a mg? There are 1000 mcg in 1 mg. Therefore, multiply that number by 1000. After multiplying 1.6 by 1000, the answer is 1600 mcg/mL.

This dopamine is packaged as 400 mg in 250 mL.

In the formula, the dosing unit is in micrograms. Therefore, the concentration used in the formula must also be the same (micrograms). For calculations, remember that the units for the top number have to match the units in the bottom number.

Let’s review the example again. Essentially, it is just multiplying the top numbers. For example, if you want to give 5 mcg multiplied by kg, which is 86, multiplied by 60 seconds, then divide by the concentration. The units for the concentration must match the drug units in the numerator. That formula calculates the dopamine infusion in mL per hour, which equals the drops per minute of 60-drop tubing. You must use 60-drop tubing. You cannot use 10 drop tubing or 59 drop tubing.

Read: ACLS Drugs – Dopamine

Verifying Accuracy of the Calculation

Now that you have performed the calculation, you want to verify the accuracy of the dopamine drip. Say you’re at the bedside with your patient. Get your calculator in your hand. The first thing you need to figure out is what is the concentration of dopamine in micrograms. The concentration is 1600 mcg/mL.

Next, all you have to do is fill in the blanks. What’s the starting dose? 5 mcg. Multiply 5 by how much the patient weighs in kg. In this case, the patient weighs 86 kg. Then, by 60 seconds. Next, divide that by the concentration, which is 1600. The pump should read 16.125 mL per hour. Is that correct?. Now, everything is verified. Remember that mL per hour on a pump is the same as drops per minute of 60 drop tubing.

Summary

This article explains how to calculate dopamine infusions. Follow the steps provided in the text and always remember to double check your calculations.