An IV administration problem: 1000 mL to be infused over 8 hours with a drop factor of 20 gtt/mL. What is the flow rate in drops per minute?

An IV administration problem: 1000 mL to be infused over 8 hours with a drop factor of 20 gtt/mL. What is the flow rate in drops per minute?

• A. 21 gtt/min
• B. 42 gtt/min
• C. 60 gtt/min
• D. 80 gtt/min

Answer: (B)

Calculating IV flow rate requires converting the prescribed volume and time into a per-minute rate and then converting milliliters to drops using the drop factor. First, find the rate in mL per hour: 1000 mL divided by 8 hours equals 125 mL/hour. Then convert to mL per minute: 125 mL/hour ÷ 60 minutes/hour ≈ 2.083 mL/min. Now use the drop factor to convert to drops per minute: 2.083 mL/min × 20 drops/mL ≈ 41.66 drops/min, which rounds to 42 gtt/min. So the flow rate is about 42 drops per minute.

Calculating IV flow rate requires converting the prescribed volume and time into a per-minute rate and then converting milliliters to drops using the drop factor.

First, find the rate in mL per hour: 1000 mL divided by 8 hours equals 125 mL/hour. Then convert to mL per minute: 125 mL/hour ÷ 60 minutes/hour ≈ 2.083 mL/min. Now use the drop factor to convert to drops per minute: 2.083 mL/min × 20 drops/mL ≈ 41.66 drops/min, which rounds to 42 gtt/min.

So the flow rate is about 42 drops per minute.