1. What is the Holliday-Segar Formula?

The Holliday-Segar formula is a method for calculating maintenance fluid requirements in pediatric patients based on body weight. It accounts for the higher metabolic rate and fluid requirements per kilogram in smaller children.

2. How Does the Calculator Work?

The calculator uses the Holliday-Segar formula:

Where:

• First 10 kg: 100 mL/kg/day (4 mL/kg/hour)
• Next 10 kg (10-20 kg): 50 mL/kg/day (2 mL/kg/hour)
• Above 20 kg: 20 mL/kg/day (1 mL/kg/hour)

Explanation: The formula approximates daily caloric expenditure (100 kcal/kg for first 10kg, 50 kcal/kg for next 10kg, 20 kcal/kg thereafter) with 1 mL of water required per kcal expended.

3. Importance of Maintenance Fluids

Details: Proper fluid maintenance is crucial for pediatric patients to prevent dehydration or fluid overload, especially in hospitalized children who cannot take fluids orally.

4. Using the Calculator

Tips: Enter the patient's weight in kilograms. The calculator will provide both daily and hourly fluid requirements. For very small infants (<1kg), consult a neonatologist.

5. Frequently Asked Questions (FAQ)

Q1: When should I use this formula?
A: For calculating maintenance fluids in children who are NPO or have restricted oral intake. Not for resuscitation or replacement of deficits.

Q2: What fluids should I use?
A: Typically D5 1/4NS with 20 mEq KCl/L for maintenance, but adjust based on individual patient needs and electrolytes.

Q3: Are there exceptions to this rule?
A: Yes, adjust for conditions like heart failure, renal failure, SIADH, or diabetes insipidus. Premature infants have different requirements.

Q4: How does this compare to body surface area calculations?
A: Holliday-Segar is simpler and more commonly used for maintenance, while BSA may be better for chemotherapy or critical care.

Q5: What about insensible losses?
A: The formula accounts for normal insensible losses. Additional losses (fever, diarrhea, burns) require separate replacement.