Final answer:
The nurse should set the IV pump to deliver 18 mL/hr of heparin infusion to administer the prescribed dose of 900 units/hr given the concentration of heparin available.
Step-by-step explanation:
To calculate the flow rate of heparin required, we start with the desired units per hour (900 units/hr) and use the concentration provided (25,000 units in 500 mL).
The equation is as follows:
(900 units/hr) / (25,000 units/500 mL) = (X mL/hr)
Multiplying both sides to solve for X gives us:
(900 units/hr) × (500 mL) / (25,000 units) = X mL/hr
X = 18 mL/hr
Therefore, the nurse should set the IV pump to deliver 18 mL/hr of the heparin infusion.