What is the estimated fluid requirement for a child based on their weight?

From the Guidelines

The estimated fluid requirement for a child is calculated using the Holliday-Segar method, which varies based on the child's weight, with 100 mL/kg/day for the first 10 kg, plus 50 mL/kg/day for each kilogram between 10-20 kg, and plus 25 mL/kg/day for each kilogram above 20 kg. This calculation method, as outlined in the espghan/espen/espr/cspen guidelines on pediatric parenteral nutrition: fluid and electrolytes 1, accounts for the higher metabolic rate and proportionally larger body surface area in smaller children, resulting in greater fluid needs per kilogram. These requirements cover basic physiological needs including insensible losses through breathing and skin, as well as urine output. Some key points to consider when estimating fluid requirements in children include:

• For children weighing up to 10 kg, the requirement is 100 mL/kg/day, which translates to 4 mL/kg/hour 1.
• For children between 10-20 kg, the requirement is 1000 mL plus 50 mL/kg for each kg above 10 kg, or 2 mL/kg/hour for each kg above 10 kg 1.
• For children weighing more than 20 kg, the requirement is 1500 mL plus 25 mL/kg for each kg above 20 kg, or 1 mL/kg/hour for each kg above 20 kg 1. It's essential to note that these are baseline requirements for maintenance fluids; additional factors such as fever, vomiting, diarrhea, or increased environmental temperature may necessitate higher fluid volumes, as emphasized in the guidelines 1. In clinical settings, ongoing assessment of hydration status through monitoring urine output, vital signs, and physical examination remains essential for appropriate fluid management.

From the Research

Estimated Fluid Requirement for Children

The estimated fluid requirement for children can be calculated based on their weight.

• The Parkland formula is often used to calculate fluid requirements in children, especially in cases of burn injury 2.
• According to the Parkland formula, the total amount of fluid required in the first 24 hours is calculated as 4 mL/kg/% total body surface area (TBSA) burned 2.
• For example, a child weighing 10 kg with 10% TBSA burned would require 4 mL/kg/% TBSA = 4 x 10 kg x 10% = 400 mL of fluid in the first 24 hours.
• Another study compared the use of Ringers lactate and Normal Saline for children with acute diarrhea and severe dehydration, and found that children in the Ringers lactate group required less fluids, with a median of 310 mL/kg compared to 530 mL/kg in the Normal Saline group 3.
• The maintenance fluid requirement for children can be estimated based on their weight, with a common formula being 100 mL/kg/day for the first 10 kg of body weight, 50 mL/kg/day for the next 10 kg, and 20 mL/kg/day for each kilogram above 20 kg 4.
• For example, a child weighing 15 kg would require 100 mL/kg/day x 10 kg = 1000 mL/day for the first 10 kg, and 50 mL/kg/day x 5 kg = 250 mL/day for the next 5 kg, for a total of 1250 mL/day.

Factors Affecting Fluid Requirements

• The type of fluid used can affect the fluid requirement, with some studies suggesting that lactated Ringer's solution may be associated with less fluid requirement compared to normal saline 3, 5.
• The underlying condition of the child, such as acute diarrhea or burn injury, can also affect the fluid requirement 2, 3.
• The child's age, weight, and overall health status should also be taken into account when estimating fluid requirements 4.