The infusion set has 20 gtt/mL. What gtt/min to deliver 60 mL/hr?

The infusion set has 20 gtt/mL. What gtt/min to deliver 60 mL/hr?

• A. 10 gtt/min
• B. 15 gtt/min
• C. 25 gtt/min
• D. 20 gtt/min

Answer: (D)

To convert mL per hour to drops per minute, use the formula gtt/min = (mL/hr) × (drip factor gtt/mL) ÷ 60. With a drip factor of 20 gtt/mL and a flow of 60 mL/hr, the calculation is (60 × 20) ÷ 60 = 20 gtt/min. So the infusion should be delivered at 20 drops per minute. For intuition: a higher drop factor means more drops per mL, so the same hourly volume results in more drops per minute. If the rate were 10 gtt/min, that would correspond to 30 mL/hr; 15 gtt/min would be 45 mL/hr; 25 gtt/min would be 75 mL/hr—unmatched to the given 60 mL/hr.

To convert mL per hour to drops per minute, use the formula gtt/min = (mL/hr) × (drip factor gtt/mL) ÷ 60. With a drip factor of 20 gtt/mL and a flow of 60 mL/hr, the calculation is (60 × 20) ÷ 60 = 20 gtt/min. So the infusion should be delivered at 20 drops per minute.

For intuition: a higher drop factor means more drops per mL, so the same hourly volume results in more drops per minute. If the rate were 10 gtt/min, that would correspond to 30 mL/hr; 15 gtt/min would be 45 mL/hr; 25 gtt/min would be 75 mL/hr—unmatched to the given 60 mL/hr.