An IV order for 1000 mL D5W to infuse over 16 hours with a drop factor of 20 gtt/mL. What is the flow rate in drops per minute?

An IV order for 1000 mL D5W to infuse over 16 hours with a drop factor of 20 gtt/mL. What is the flow rate in drops per minute?

• A. 10 gtt/min
• B. 21 gtt/min
• C. 25 gtt/min
• D. 40 gtt/min

Answer: (B)

Flow rate in drops per minute comes from combining the volume to be infused, the drop factor, and the total time, all in compatible units. Use the relationship: flow rate (gtt/min) = (volume in mL × drop factor) ÷ (time in minutes). Convert 16 hours to minutes: 16 × 60 = 960 minutes. Compute the total drops: 1000 mL × 20 gtt/mL = 20,000 gtt. Then 20,000 gtt ÷ 960 min ≈ 20.83 gtt/min. Rounding to the nearest whole drop gives 21 gtt/min. So the infusion rate is about 21 drops per minute. Other options don’t fit because they would require a different combination of volume, time, or drop factor.

Flow rate in drops per minute comes from combining the volume to be infused, the drop factor, and the total time, all in compatible units. Use the relationship: flow rate (gtt/min) = (volume in mL × drop factor) ÷ (time in minutes).

Convert 16 hours to minutes: 16 × 60 = 960 minutes. Compute the total drops: 1000 mL × 20 gtt/mL = 20,000 gtt. Then 20,000 gtt ÷ 960 min ≈ 20.83 gtt/min. Rounding to the nearest whole drop gives 21 gtt/min.

So the infusion rate is about 21 drops per minute. Other options don’t fit because they would require a different combination of volume, time, or drop factor.