Question

A hypertensive patient weighs 165 lbs. The physician prescribed 3mcg/kg/minute, IV. To administer, 50 mg of Nipride has to be added to a 250mL solution of D5W. The solution would contain a concentration of Nipride, how many mcg/mL? Using an infusion pump, the nurse would set the flow rate at how many mLs/hr?

Answer 1

Answer: Concentration of Nipride is  200 mcg/mL

The nurse would set the flow rate at 67.5 mL/hr

Solution:

i. Concentration of Nipride:

By using dimensional anlaysis method: In this method, the equation is set up such that only required dimensions are obtained (i.e mcg/mL in this case) and the remaining units are cancelled off using appropriate conversion factors.

50 mg of Nipride is added to a 250mL solution of D5W (Dextrose 5% in water for injection) i.e 50 mg/250 mL

Concentration in mcg/mL=   (since 1mg=10000mcg)

= (50,000/250) mcg/mL (mg gets cancelled off, giving the required mcg/mL units)

= 200 mcg/mL

ii. Flow rate:

Body weight of the cient = 165 lbs = = 75 kgs

Prescribed dose = 3 mcg/kg/min

Using cross multiplication

1kg of body weight requires 3 mcg of drug

Let, 75 kgs of body weight requires X mcg of drug

Then, X = = 225 mcg/min

Concentration of drug available (From i above) = 200 mcg/mL

By using dimensional analysis:

Flow rate (mL/hr) =

= (13,500/ 200) mL/hr [Remaining units are cancelled off]

= 67.5 mL/hr

Hence, the nurse should set the flow rate at 67.5 mL/hr