If an IV is to infuse 1000 mL over 8 hours and 600 mL remain at 1500 hours, what should the rate be to finish by 1900 hours?

If an IV is to infuse 1000 mL over 8 hours and 600 mL remain at 1500 hours, what should the rate be to finish by 1900 hours?

• A. 125 mL/hr
• B. 150 mL/hr
• C. 75 mL/hr
• D. 100 mL/hr

Answer: (B)

Calculate what’s left to infuse and how much time is left to the target end time. The volume remaining is 600 mL, and from 1500 to 1900 is 4 hours. Rate equals remaining volume divided by remaining time: 600 mL ÷ 4 h = 150 mL/hr. So, set the IV to run at 150 mL per hour to finish by 1900. If you used the original plan of 125 mL/hr, you wouldn’t finish on time.

Calculate what’s left to infuse and how much time is left to the target end time. The volume remaining is 600 mL, and from 1500 to 1900 is 4 hours. Rate equals remaining volume divided by remaining time: 600 mL ÷ 4 h = 150 mL/hr. So, set the IV to run at 150 mL per hour to finish by 1900. If you used the original plan of 125 mL/hr, you wouldn’t finish on time.