A 500 cc solution of D5NS with 20,000 units of Heparin is infusing at 20 mL per hour. The IV set delivers 60 gtt per cc. How many units of Heparin is the patient receiving each hour?

A 500 cc solution of D5NS with 20,000 units of Heparin is infusing at 20 mL per hour. The IV set delivers 60 gtt per cc. How many units of Heparin is the patient receiving each hour?

• A. 400 units/h
• B. 600 units/h
• C. 1200 units/h
• D. 800 units/h

Answer: (D)

Understanding how many units per hour come from a given concentration and infusion rate is key. First find the concentration of heparin in the solution: 20,000 units in 500 mL means 20,000 / 500 = 40 units per mL. The infusion is running at 20 mL per hour, so the patient receives 40 units/mL × 20 mL/hour = 800 units per hour. The drip factor (60 drops per mL) isn’t needed for this calculation since the question asks for units per hour, not drops per minute; that factor would be used only if you needed the flow in drops per minute.

Understanding how many units per hour come from a given concentration and infusion rate is key. First find the concentration of heparin in the solution: 20,000 units in 500 mL means 20,000 / 500 = 40 units per mL. The infusion is running at 20 mL per hour, so the patient receives 40 units/mL × 20 mL/hour = 800 units per hour. The drip factor (60 drops per mL) isn’t needed for this calculation since the question asks for units per hour, not drops per minute; that factor would be used only if you needed the flow in drops per minute.