Nursing Acceleration Challenge Exam (NACE) PN-RN Practice Test

If a patient is receiving 1000 mL of IV fluids over 8 hours, when should 250 mL remain in the IV bag if started at 8 a.m.?

1. 10 p.m.

2. 12 noon.

3. 2 p.m.

4. 4 p.m.

The correct answer is: 2 p.m.

To determine when 250 mL should remain in the IV bag, we first need to calculate the rate at which the IV fluids are being administered. The total volume of fluids is 1000 mL, and they are to be infused over 8 hours. By dividing the total volume by the total time, we find that the infusion rate is 125 mL per hour (1000 mL divided by 8 hours). Next, we need to find out how long it will take for 750 mL to be infused from the bag. Since only 250 mL should remain in the bag at that point, we need to infuse 750 mL first (1000 mL - 250 mL). To find the time required to infuse 750 mL, we divide that volume by the infusion rate: 750 mL ÷ 125 mL/hour = 6 hours. Adding this time (6 hours) to the start time of 8 a.m. gives us a finishing time of 2 p.m. At 2 p.m., there should be 250 mL left in the IV bag, confirming that option 2 p.m. is indeed the correct response.