An infusion of 100 mL of D51/2NS with 40 mEq of potassium chloride is to be given over 60 minutes. The set calibration is 15 gtt/mL. What is the correct rate in drops per minute (nearest whole number)?

An infusion of 100 mL of D51/2NS with 40 mEq of potassium chloride is to be given over 60 minutes. The set calibration is 15 gtt/mL. What is the correct rate in drops per minute (nearest whole number)?

• A. 15 gtt/min
• B. 20 gtt/min
• C. 25 gtt/min
• D. 30 gtt/min

Answer: (C)

Infusion rate in drops per minute is calculated from the volume to be infused, the time over which it should run, and the tubing’s drop factor. Multiply the volume (in mL) by the drop factor (drops per mL) and divide by the time (minutes). Here, 100 mL over 60 minutes with a 15 gtt/mL set gives: 100 × 15 = 1500 drops over 60 minutes, and 1500 ÷ 60 = 25 drops per minute. So the correct rate is 25 gtt/min. The drug content doesn’t affect the calculation; only volume, time, and tubing drop factor determine the rate.

Infusion rate in drops per minute is calculated from the volume to be infused, the time over which it should run, and the tubing’s drop factor. Multiply the volume (in mL) by the drop factor (drops per mL) and divide by the time (minutes). Here, 100 mL over 60 minutes with a 15 gtt/mL set gives: 100 × 15 = 1500 drops over 60 minutes, and 1500 ÷ 60 = 25 drops per minute. So the correct rate is 25 gtt/min. The drug content doesn’t affect the calculation; only volume, time, and tubing drop factor determine the rate.