What is the ideal maintenance fluid rate for an adult in ml per pound per hour?

• A. 1 ml/lb/hr
• B. 5 ml/lb/hr
• C. 0.5 ml/lb/hr
• D. 2 ml/lb/hr

Answer: (A)

Maintenance fluids aim to meet ongoing daily needs without causing overload. For adults, the typical maintenance requirement is about 25–30 mL per kilogram per day, which translates to roughly 1 mL per kilogram per hour. When you convert to pounds, 1 kg is about 2.2 lb, so this is around 0.45 mL per pound per hour (often rounded to about 0.5 mL/lb/hr). The given option reflects expressing maintenance in a per-pound per-hour format that lines up with this general maintenance level. Using much higher rates would risk fluid overload, while much lower rates would not meet ongoing needs.