500 mL of normal saline with 2 g potassium chloride is to be given IV. How long will this take if the infusion pump is set at 75 mL/h?

500 mL of normal saline with 2 g potassium chloride is to be given IV. How long will this take if the infusion pump is set at 75 mL/h?

• A. 6 hours 20 minutes
• B. 7 hours
• C. 6 hours 40 minutes
• D. 6 hours 0 minutes

Answer: (C)

The main idea is to find how long it takes to deliver a set volume at a given flow rate. Time equals volume divided by the infusion rate. Compute: 500 mL ÷ 75 mL/hour = 6.666… hours. The fractional part 0.666… hours converts to minutes: 0.666… × 60 = 40 minutes. So the infusion takes 6 hours and 40 minutes. Note: The amount of potassium chloride doesn’t change the time; it’s the volume to be infused and the pump rate that determine duration.

The main idea is to find how long it takes to deliver a set volume at a given flow rate. Time equals volume divided by the infusion rate.

Compute: 500 mL ÷ 75 mL/hour = 6.666… hours. The fractional part 0.666… hours converts to minutes: 0.666… × 60 = 40 minutes. So the infusion takes 6 hours and 40 minutes.

Note: The amount of potassium chloride doesn’t change the time; it’s the volume to be infused and the pump rate that determine duration.