A physician orders intravenous fluids 1,000 mL of D5NS to be administered over eight hours. If the infusion is proceeding correctly, how many milliliters should be left in the bag after six hours?

• A. 150
• B. 250
• C. 200
• D. 300

Answer: (B)

This question tests how to calculate remaining IV fluid by using the infusion rate. The total volume is 1000 mL to be given over 8 hours, so the hourly rate is 1000 ÷ 8 = 125 mL per hour. In six hours, the patient would have received 125 × 6 = 750 mL. Subtracting from the starting volume gives 1000 − 750 = 250 mL left in the bag. So after six hours, 250 mL remains.