NCLEX-PN® ExaminationPharmacological TherapiesHard
A client is prescribed intravenous dopamine at 5 mcg/kg/min. The client weighs 150 lbs. The pharmacy supplies dopamine at a concentration of 400 mg in 250 mL D5W. The LPN should set the infusion pump to deliver how many mL/hr? (Round to the nearest whole number. Do not use trailing zeros.)
- A16 mL/hr
- B28 mL/hr
- C8 mL/hr
- D13 mL/hr
Show answer & explanationAnswer & explanation
Correct answer: D. 13 mL/hr
First, convert pounds to kilograms: 150 lbs / 2.2 lbs/kg = 68.18 kg. Next, calculate the total mcg/min needed: 5 mcg/kg/min * 68.18 kg = 340.9 mcg/min. Convert mg to mcg: 400 mg = 400,000 mcg. Calculate the concentration: 400,000 mcg / 250 mL = 1600 mcg/mL. Finally, calculate mL/hr: (340.9 mcg/min / 1600 mcg/mL) * 60 min/hr = 12.78 mL/hr. Rounded to the nearest whole number, this is 13 mL/hr.
Why the other options are wrong
- A. Incorrect calculation, likely a misstep in dose or concentration conversion.
- B. Incorrect calculation, likely a significant error in one of the conversion or calculation steps.
- C. Incorrect calculation, possibly due to error in conversion or setup.
Dopamine Infusion Calculation
Calculation of intravenous dopamine infusion rate (mL/hr) based on client weight, ordered dose (mcg/kg/min), and available drug concentration.
- Convert lbs to kg.
- Convert mg to mcg.
- Use dimensional analysis for accuracy.
Memory trick: Weight, Dose, Concentration, Time: The Rhythm for IV Calc Rhyme!