A patient needs 55 mL of fluid per hour. The infusion set has 10 gtt/mL. What is the drip rate in gtt/min?

A patient needs 55 mL of fluid per hour. The infusion set has 10 gtt/mL. What is the drip rate in gtt/min?

• A. 18.3 gtt/min
• B. 55.0 gtt/min
• C. 9.17 gtt/min
• D. 28.0 gtt/min

Answer: (C)

This question tests converting an hourly infusion rate to a drip rate in drops per minute using the drip factor. The formula is drip rate (gtt/min) = (volume per hour in mL) × (drip factor in gtt/mL) ÷ 60. Compute: 55 mL/hr × 10 gtt/mL = 550 gtt/hr. Then convert to per minute: 550 gtt/hr ÷ 60 min/hr ≈ 9.1667 gtt/min, which rounds to 9.17 gtt/min. So the correct drip rate is 9.17 gtt/min. A common mistake is dividing by 30 instead of 60, which would give about 18.3 gtt/min, or forgetting to apply the drip factor, which could lead to other incorrect values like 55.0 gtt/min.

This question tests converting an hourly infusion rate to a drip rate in drops per minute using the drip factor. The formula is drip rate (gtt/min) = (volume per hour in mL) × (drip factor in gtt/mL) ÷ 60.

Compute: 55 mL/hr × 10 gtt/mL = 550 gtt/hr. Then convert to per minute: 550 gtt/hr ÷ 60 min/hr ≈ 9.1667 gtt/min, which rounds to 9.17 gtt/min.

So the correct drip rate is 9.17 gtt/min. A common mistake is dividing by 30 instead of 60, which would give about 18.3 gtt/min, or forgetting to apply the drip factor, which could lead to other incorrect values like 55.0 gtt/min.