Starting a 100 mL/hr infusion of 3% hypertonic saline through tubing with a drip factor of 10 gtt/mL yields how many drops per minute?

Starting a 100 mL/hr infusion of 3% hypertonic saline through tubing with a drip factor of 10 gtt/mL yields how many drops per minute?

• A. 15 gtt/min
• B. 17 gtt/min
• C. 20 gtt/min
• D. 25 gtt/min

Answer: (B)

To find drops per minute, use the drip factor to convert the hourly milliliter rate into drops per hour, then convert to per minute. With a drip factor of 10 gtt/mL, 100 mL per hour yields 100 × 10 = 1000 drops per hour. Divide by 60 minutes per hour to get drops per minute: 1000 ÷ 60 ≈ 16.7 gtt/min. Rounding to the nearest whole drop gives 17 gtt/min. Therefore, the infusion rate is about 17 drops per minute.

To find drops per minute, use the drip factor to convert the hourly milliliter rate into drops per hour, then convert to per minute.

With a drip factor of 10 gtt/mL, 100 mL per hour yields 100 × 10 = 1000 drops per hour. Divide by 60 minutes per hour to get drops per minute: 1000 ÷ 60 ≈ 16.7 gtt/min. Rounding to the nearest whole drop gives 17 gtt/min. Therefore, the infusion rate is about 17 drops per minute.