The Holliday-Segar formula estimates daily maintenance fluid requirements in pediatrics based on what parameter?

• A. Weight
• B. Age
• C. Hydration status
• D. Height

Answer: (A)

Maintenance fluid requirements in healthy children are determined primarily by body weight. The Holliday-Segar method links how much fluid a child needs to their size, not their age, height, or hydration status. It estimates daily maintenance fluids with a tiered weight-based approach: 100 mL per kilogram for the first 10 kg, 50 mL per kilogram for the next 10 kg, and 20 mL per kilogram for each kilogram over 20 kg. Clinically, this is often translated to an hourly rate using the 4-2-1 rule: 4 mL/kg/h for the first 10 kg, 2 mL/kg/h for the next 10 kg, and 1 mL/kg/h for each kg over 20 kg. For example, a 15-kg child would need about 1250 mL per day, roughly 50 mL per hour. This weight-based approach reflects how metabolic and excretory demands scale with body size, guiding baseline maintenance needs.