What is the required flow rate of a volumetric infusion pump to deliver 500 mL of dextrose 5% over 12 hours? (Answer in mL/h, rounded to the nearest whole number.)

What is the required flow rate of a volumetric infusion pump to deliver 500 mL of dextrose 5% over 12 hours? (Answer in mL/h, rounded to the nearest whole number.)

• A. 41 mL/h
• B. 42 mL/h
• C. 43 mL/h
• D. 40 mL/h

Answer: (A)

Flow rate is the total volume to be delivered divided by the total time over which it’s given. For 500 mL over 12 hours, divide 500 by 12 to get about 41.6667 mL/hour. When you round to the nearest whole number for a pump that uses whole mL per hour, that becomes 42 mL/h. Therefore, the required flow rate is 42 mL/h. Over 12 hours, at 42 mL/h, the pump would deliver about 504 mL, which is the closest whole-number setting to 500 mL. If a pump could use decimals, 41.7 mL/h would be even closer, but with whole-number increments, 42 mL/h is the standard choice.

Flow rate is the total volume to be delivered divided by the total time over which it’s given. For 500 mL over 12 hours, divide 500 by 12 to get about 41.6667 mL/hour. When you round to the nearest whole number for a pump that uses whole mL per hour, that becomes 42 mL/h. Therefore, the required flow rate is 42 mL/h. Over 12 hours, at 42 mL/h, the pump would deliver about 504 mL, which is the closest whole-number setting to 500 mL. If a pump could use decimals, 41.7 mL/h would be even closer, but with whole-number increments, 42 mL/h is the standard choice.