A patient requires 750 mL of normal saline with drop factor 15 gtt/mL to run over 3 hours. What is the rate in gtt/min?

A patient requires 750 mL of normal saline with drop factor 15 gtt/mL to run over 3 hours. What is the rate in gtt/min?

• A. 40 gtt/min
• B. 70 gtt/min
• C. 56 gtt/min
• D. 50 gtt/min

Answer: (C)

Infusion rate in gtt/min is found by multiplying the volume to be infused (mL) by the drop factor (gtt/mL) and then dividing by the time (minutes). So, 750 mL × 15 gtt/mL gives 11,250 gtt to deliver. The time is 3 hours, which is 180 minutes. Dividing gives 11,250 ÷ 180 = 62.5 gtt/min. The exact rate is 62.5 gtt/min, which isn’t one of the listed options. The closest listed value is around 56 gtt/min, which is why that option might be selected as the best match among given choices. If rounding is used, you would report about 63 gtt/min.

Infusion rate in gtt/min is found by multiplying the volume to be infused (mL) by the drop factor (gtt/mL) and then dividing by the time (minutes). So, 750 mL × 15 gtt/mL gives 11,250 gtt to deliver. The time is 3 hours, which is 180 minutes. Dividing gives 11,250 ÷ 180 = 62.5 gtt/min. The exact rate is 62.5 gtt/min, which isn’t one of the listed options. The closest listed value is around 56 gtt/min, which is why that option might be selected as the best match among given choices. If rounding is used, you would report about 63 gtt/min.