If an IV bag contains 500 mL and the infusion is set at 25 mL per hour, how long will the bag last?

If an IV bag contains 500 mL and the infusion is set at 25 mL per hour, how long will the bag last?

• A. 20 hours
• B. 10 hours
• C. 40 hours
• D. 25 hours

Answer: (A)

Infusion time is found by dividing the total volume by the infusion rate. A 500 mL bag at 25 mL per hour will run for 500 ÷ 25 = 20 hours. This checks out because delivering 25 mL every hour for 20 hours totals 500 mL. If it were to last 10 hours, the rate would need to be 50 mL/hour; for 40 hours, 12.5 mL/hour; for 25 hours, 20 mL/hour. Therefore, 20 hours is the correct duration.

Infusion time is found by dividing the total volume by the infusion rate. A 500 mL bag at 25 mL per hour will run for 500 ÷ 25 = 20 hours. This checks out because delivering 25 mL every hour for 20 hours totals 500 mL. If it were to last 10 hours, the rate would need to be 50 mL/hour; for 40 hours, 12.5 mL/hour; for 25 hours, 20 mL/hour. Therefore, 20 hours is the correct duration.