What is the daily maintenance fluid requirement for an euvolemic 25‑kg child without fever or fluid‑restrictive conditions?

Daily Maintenance Fluid Requirement for a 25 kg Child

A 25 kg child requires 1600 mL per day (or 65 mL/hour) of isotonic maintenance fluid under standard conditions. 1, 2

Calculation Using the Holliday-Segar Formula

The calculation breaks down by weight segments 1, 2, 3:

• First 10 kg: 100 mL/kg/day = 1000 mL/day
• Second 10 kg (10-20 kg): 50 mL/kg/day = 500 mL/day
• Remaining 5 kg (above 20 kg): 25 mL/kg/day = 125 mL/day

Total: 1625 mL/day (approximately 1600 mL/day or 65-70 mL/hour) 1, 2, 3

This formula remains the standard method for calculating maintenance water needs in children by determining caloric and water requirements from weight alone. 1, 2

Fluid Composition Requirements

Use isotonic fluids (sodium 130-154 mEq/L) with dextrose and potassium for all hospitalized children to prevent hospital-acquired hyponatremia. 1, 4 The traditional use of hypotonic maintenance fluids has directly caused over 50 cases of neurologic morbidity including 26 deaths in children. 4

Balanced isotonic solutions (lactated Ringer's or PlasmaLyte) should be favored over 0.9% NaCl to slightly reduce length of stay and avoid hyperchloremic acidosis. 1, 4

Add the following to maintenance fluids 1, 2, 4:

• Glucose: 2.5-5% dextrose to prevent hypoglycemia, monitored at least daily
• Potassium: Appropriate supplementation based on clinical status and regular monitoring to avoid hypokalemia

Critical Adjustments for Special Clinical Situations

The standard 1600 mL/day calculation assumes a euvolemic child without complicating factors. You must reduce this volume in specific high-risk scenarios 1, 2, 4:

Reduce to 65-80% of calculated volume (1040-1280 mL/day) if:

• Increased ADH secretion risk (pneumonia, CNS infections, postoperative state, dehydration) 1, 2, 4
• Mechanical ventilation 1
• Temperature-controlled environments 1

Reduce to 50-60% of calculated volume (800-960 mL/day) if:

• Heart failure 2
• Renal failure 1, 2
• Hepatic failure 2

Increase volume above standard calculation if:

• Fever (increases requirements) 1, 3
• Hyperventilation 1, 3
• Hypermetabolism 1
• Ongoing gastrointestinal losses 1, 3

Total Daily Fluid Accounting

The 1600 mL/day maintenance calculation must include ALL fluid sources 1, 2, 4:

• IV maintenance fluids
• Blood products
• All IV medications (infusions and boluses)
• Arterial and venous line flush solutions
• Enteral intake

This does not include replacement fluids for acute losses or massive transfusion. 1, 2

Monitoring Requirements

Reassess at least daily 2, 4:

• Fluid balance and clinical status
• Serum electrolytes, especially sodium
• Blood glucose levels
• Weight and intake/output

Critical Pitfalls to Avoid

Never use hypotonic fluids (sodium <130 mEq/L) as standard maintenance in hospitalized children—this practice has caused fatal hyponatremic encephalopathy. 4, 5 The postoperative period and acute illness are associated with nonosmotic ADH secretion, which reduces the kidneys' ability to excrete free water, making hypotonic solutions particularly dangerous. 6, 5

Do not ignore "hidden" fluid sources from medications, flushes, and blood products, as these contribute significantly to total daily intake and can lead to unintended fluid overload. 1, 2, 4

Avoid continuing full maintenance rates without reassessment in children with established fluid overload, oliguria, or changing clinical conditions. 1, 2