Using a microdrip set delivering 60 drops/mL, what is the required drip rate, in drops per minute, to infuse 400 mL over 10 hours?

Using a microdrip set delivering 60 drops/mL, what is the required drip rate, in drops per minute, to infuse 400 mL over 10 hours?

• A. 40 gtt/min
• B. 50 gtt/min
• C. 60 gtt/min
• D. 30 gtt/min

Answer: (A)

Calculating the drip rate means turning the total volume and total time into a drops-per-minute value using the drip factor. With a microdrip of 60 drops per mL, delivering 400 mL in 10 hours first convert time to minutes: 10 hours equals 600 minutes. The volume per minute is 400 mL / 600 min = 2/3 mL per minute. Since 1 mL yields 60 drops, the rate in drops per minute is (2/3) × 60 = 40 gtt/min. Using the direct formula Drip rate = Volume × Drip factor / Time (in minutes) gives 400 × 60 / 600 = 40 gtt/min. Quick checks: at 50 gtt/min you’d infuse about 500 mL in 10 hours; at 60 gtt/min you’d reach about 600 mL; at 30 gtt/min you’d deliver about 300 mL. So the required rate is 40 drops per minute.

Calculating the drip rate means turning the total volume and total time into a drops-per-minute value using the drip factor. With a microdrip of 60 drops per mL, delivering 400 mL in 10 hours first convert time to minutes: 10 hours equals 600 minutes. The volume per minute is 400 mL / 600 min = 2/3 mL per minute. Since 1 mL yields 60 drops, the rate in drops per minute is (2/3) × 60 = 40 gtt/min. Using the direct formula Drip rate = Volume × Drip factor / Time (in minutes) gives 400 × 60 / 600 = 40 gtt/min. Quick checks: at 50 gtt/min you’d infuse about 500 mL in 10 hours; at 60 gtt/min you’d reach about 600 mL; at 30 gtt/min you’d deliver about 300 mL. So the required rate is 40 drops per minute.