Over the next 4 hours, infuse 500 mL of 5% Dextrose in normal saline. Add 20 mEq of KCl to solution. You know that the IV tubing is calibrated to deliver 10 gtt/mL. In drops per minute, what is the rate of flow? (Answer in gtt/min rounded to the nearest whole number)

Over the next 4 hours, infuse 500 mL of 5% Dextrose in normal saline. Add 20 mEq of KCl to solution. You know that the IV tubing is calibrated to deliver 10 gtt/mL. In drops per minute, what is the rate of flow? (Answer in gtt/min rounded to the nearest whole number)

• A. 20 gtt/min
• B. 21 gtt/min
• C. 22 gtt/min
• D. 19 gtt/min

Answer: (B)

The main idea is converting a prescribed volume to a drops-per-minute rate using the tubing’s drop factor. Start by finding the infusion rate in mL per hour: 500 mL over 4 hours equals 125 mL/hour. With a drop factor of 10 gtt/mL, the rate in drops per hour is 125 mL/hour × 10 gtt/mL = 1250 gtt/hour. Convert to drops per minute by dividing by 60: 1250 / 60 ≈ 20.8 gtt/min, which rounds to 21 gtt/min. The addition of 20 mEq KCl doesn’t change the volume to be infused, so it doesn’t affect the flow rate calculation. Therefore, the rate is 21 gtt/min.

The main idea is converting a prescribed volume to a drops-per-minute rate using the tubing’s drop factor. Start by finding the infusion rate in mL per hour: 500 mL over 4 hours equals 125 mL/hour. With a drop factor of 10 gtt/mL, the rate in drops per hour is 125 mL/hour × 10 gtt/mL = 1250 gtt/hour. Convert to drops per minute by dividing by 60: 1250 / 60 ≈ 20.8 gtt/min, which rounds to 21 gtt/min. The addition of 20 mEq KCl doesn’t change the volume to be infused, so it doesn’t affect the flow rate calculation. Therefore, the rate is 21 gtt/min.