Med Math: Drop Factors Question #19
Dopamine is ordered at 5 mcg/kg/min. The bag is labeled: “Dopamine 400 mg/250 ml” and the Client’s weight is 63 kg. Calculate rate ml/hr.
- 24 mL/hr
- 12 mL/hr
- 33 mL/hr
- 14 mL/hr
Dopamine is ordered in a bag of 400 mg/250ml. The nurse needs to find the mcg per minute in order to solve the problem. Step 1- Do not Convert given wt. of Kg to Lbs. As the Kg matches in both the stem and scenario. The problem will now look similar to the original dosage problem such as 5 mcg/ 63kg/min. Another way to look at the problem is to think that a 63 kg client is getting 5mcg of medicine per minute.
nSTEP 2- Convert 400 mg to mcg. Move the decimal 3 places to the left. You now have 400,000 mcg of medicine. STEP 3 – Multiply appropriate wt. calculated by the dose of 5 mcg then multiple again by volume of 250 ml and times expressed in 60 mins.Then divide by the ordered dose or what you have which is 400,000 mcg.
STEP 4 – Round the answer accordingly to a whole number. There is a simple formula below for calculating the dose to be given. The final answer should have ml/hr within.
Dose ordered x weight (if weight based) x volume x time
Dose ordered x wt x vol x time / dose on hand
5mcg/kg/min x 63 kg x 250 mL x 60 min/hr / 400,000 mcg (converted 400 mg on hand to mcg) = 4,725,000/ 400,000 = 11.8 mL/hr ROUND up to 12 mL/hr
IF you use DA the equation will be longer!