In the context of fluid volume management, which of the following is used to assess fluid balance?

• A. Measure intake and output
• B. Check blood pressure only
• C. Assess vision
• D. Check hearing

Answer: (A)

Fluid balance is determined by comparing what comes into the body with what leaves it. The most direct and practical way to assess this is to measure intake and output over a set period, typically 24 hours. This includes all fluid sources (oral fluids, IV fluids, tube feeds, and even meds that contain fluids) and all losses (urine, vomiting, diarrhea, wound or drain drainage, gastric suction, sweat, and insensible losses). By calculating the net balance, you can gauge whether a patient is hypovolemic, euvolemic, or hypervolemic and track trends over time to guide therapy. Weight change can support the assessment but isn’t as direct as monitoring intake and output. Blood pressure, vision, or hearing are not reliable stand-alone measures of fluid balance, since they reflect multiple other factors beyond total body fluid.