You just divide the total dosage of the med in the bag by the total volume, to get mg /cc , then multiply times 1000 if it is to be micrograms (if mg were added to the bag), then divide it by the patient's weight (if it is to be mcg/kg), then divide it by 60 if it is to be mcg/kg/min. If it is just MCG /min just skip the dividing it by the pt's weight. really just common math. Dopamine is calculated mcg/kg/min. So if it is mixed 400mg in 250 cc's, as is standard, we divide 400/250 to equal 1.6mg per cc, but since dopamine is calculated in mcg we multiply that times 1000 to equal 1600 mcg per cc. Now we divide that times the patient's weight in kg ( as dopamine is calculated mcg/KG/min), then we divide that by 60 to figure (mcg/kg/MIN). that is your constant. and then every time you change the rate (ml/hour) you just multiply the rate times the constant to get mcg/kg/min.
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