If a 2 L IV bag is set to run at 20 drops per mL and the infusion rate is 30 drops per minute, what is the mL per hour?

If a 2 L IV bag is set to run at 20 drops per mL and the infusion rate is 30 drops per minute, what is the mL per hour?

• A. 60 mL/hour
• B. 120 mL/hour
• C. 90 mL/hour
• D. 45 mL/hour

Answer: (C)

To find the milliliters per hour, convert drops to milliliters first. With 20 drops per milliliter, a rate of 30 drops per minute equals 30 ÷ 20 = 1.5 mL per minute. Multiply by 60 minutes in an hour: 1.5 × 60 = 90 mL per hour. The 2 L bag size isn’t needed to determine the rate, but it means the bag would last about 2000 ÷ 90 ≈ 22 hours at this rate. So the mL per hour is 90.

To find the milliliters per hour, convert drops to milliliters first. With 20 drops per milliliter, a rate of 30 drops per minute equals 30 ÷ 20 = 1.5 mL per minute. Multiply by 60 minutes in an hour: 1.5 × 60 = 90 mL per hour. The 2 L bag size isn’t needed to determine the rate, but it means the bag would last about 2000 ÷ 90 ≈ 22 hours at this rate. So the mL per hour is 90.