If the IV rate is 500 mL/hour and urine output exceeds 50 mL/hour, what is the new rate after applying the guideline?

• A. 375 mL/hour
• B. 450 mL/hour
• C. 500 mL/hour
• D. 425 mL/hour

Answer: (A)

Maintaining fluid balance uses urine output to guide IV maintenance. When urine production is adequate and exceeds a threshold (50 mL/hour in this guideline), the recommendation is to lower the IV maintenance rate by 25%. Starting at 500 mL/hour, a 25% reduction is 125 mL/hour, leaving 375 mL/hour. So the new rate is 375 mL/hour. This adjustment helps balance intake with output and avoid fluid overload.