What is the required flow rate in mL/h to deliver 1 L of normal saline over 8 hours?

What is the required flow rate in mL/h to deliver 1 L of normal saline over 8 hours?

• A. 100 mL/h
• B. 125 mL/h
• C. 150 mL/h
• D. 175 mL/h

Answer: (B)

Infusion rate is found by dividing the total volume to be given by the total time over which it should be delivered. Convert 1 liter to milliliters: 1 L = 1000 mL. If you want that 1000 mL to run over 8 hours, you divide 1000 mL by 8 h, giving 125 mL per hour. So the required flow rate is 125 mL/h. For context, at 100 mL/h the infusion would take 10 hours; at 150 mL/h it would finish in 6 hours 40 minutes; at 175 mL/h it would finish in about 5 hours 43 minutes.

Infusion rate is found by dividing the total volume to be given by the total time over which it should be delivered. Convert 1 liter to milliliters: 1 L = 1000 mL. If you want that 1000 mL to run over 8 hours, you divide 1000 mL by 8 h, giving 125 mL per hour. So the required flow rate is 125 mL/h.

For context, at 100 mL/h the infusion would take 10 hours; at 150 mL/h it would finish in 6 hours 40 minutes; at 175 mL/h it would finish in about 5 hours 43 minutes.