dosage and calculation

Question

A continuous infusion of regular insulin at 7 units/hour has been ordered for a patient with type 1 diabetes mellitus. The pharmacy dispensed a standard insulin infusion containing 100 units of regular U-100 insulin in 100 mL normal saline. At what rate in mL/hr should the infusion pump be set?

Answer 1

Stock = 100 U / 100 ml

Needed: 7 U / hr infusion

? how many ml/hr is the rate to be set

7 U / hr x 100 ml / 100 U = 7 ml / hr = infusion rate

Or, converting the stock to U / ml, we have 100 U / 100 ml = 1 U/ml

7 U / hr x 1 ml /1 U = 7 ml/hr = infusion rate