A physician prescribes 100 mL of 0.9% saline to infuse over 45 minutes. What is the required infusion rate in mL/hour?

A physician prescribes 100 mL of 0.9% saline to infuse over 45 minutes. What is the required infusion rate in mL/hour?

• A. 118 mL/hr
• B. 133 mL/hr
• C. 150 mL/hr
• D. 160 mL/hr

Answer: (B)

Infusion rate equals the total volume divided by the total time. The time is 45 minutes, which is 0.75 hours (45/60). Rate = 100 mL / 0.75 h = 133.33 mL/hour, so about 133 mL/hour when rounded to the nearest whole number. Another way: 100 mL in 45 minutes is 2.22 mL per minute, and multiplying by 60 minutes per hour gives 133.3 mL/hour. This is the rate to set for the infusion.

Infusion rate equals the total volume divided by the total time. The time is 45 minutes, which is 0.75 hours (45/60).

Rate = 100 mL / 0.75 h = 133.33 mL/hour, so about 133 mL/hour when rounded to the nearest whole number.

Another way: 100 mL in 45 minutes is 2.22 mL per minute, and multiplying by 60 minutes per hour gives 133.3 mL/hour. This is the rate to set for the infusion.