Question

Order: 5 mcg/kg/min for a pt that weighs 194 lbs. You have 400 mg in a 250 mL of NS What is the flow rate? What is the drop rate if the tubing is rated at 60 gtt/ml?

Answer 1

Solution:

Ordered dose = 5mcg/kg/min.

Pt weighs = 194lbs

Convert pt weight from kg into the pound.

1kg = 2.2 lbs

194 lbs = 194/2.2

= 88.1 kg.

Calculate pt dosage

Dose = 5mcg/kg

= 88 x 5

Dose = 440 mcg/min.

For an hour, the dose = 440 X 60 = 26400 mcg/hr

Convert the dosage mcg into mg

1mg = 1000mcg

= 26400 / 1000

= 26.4mg/hr.

Calculate the flow rate

Flow rate (mL/hr) = Ordered dose per hour / Dose on hand X volume

= 26.4 / 400 x 25

Flow rate = 16.4mL/hr

Calculate drop rate:

Total infusion time = Total volume / flow rate

= 400 / 16.4 = 24.3

Total infusion time = 24 (rounded off).

Drop rate = Total volume of infusion x drop factor / Total time of infusion in min

Total volume of infusion = 400

Drop factor = 60gtt/min

Total time of infsion = 24 x 60 (to convert into min)

Drop factor = 400 x 60 / 24 x 60

Drop factor = 16.6 drops /min