What is the recommended dose of maintenance fluids for a child over 20 kilograms (kg)?

Maintenance Fluid Dosing for Children Over 20 kg

For children weighing more than 20 kg, the recommended maintenance fluid rate is 1 ml/kg/h. 1

Maintenance Fluid Requirements Based on Weight

The Holliday and Segar formula remains the gold standard for calculating maintenance fluid requirements in pediatric patients:

• First 10 kg: 4 ml/kg/h (100 ml/kg/day) 1
• Second 10 kg (10-20 kg): 2 ml/kg/h (50 ml/kg/day) 1
• Each kg above 20 kg: 1 ml/kg/h (25 ml/kg/day) 1

Calculation Example

For a child weighing 30 kg:

• First 10 kg: 10 × 4 ml/h = 40 ml/h
• Second 10 kg: 10 × 2 ml/h = 20 ml/h
• Remaining 10 kg: 10 × 1 ml/h = 10 ml/h
• Total maintenance rate: 70 ml/h 1

Fluid Type Considerations

• Isotonic fluids are recommended for maintenance hydration in hospitalized children, especially during the first 24 hours 1
• This approach reduces the risk of hospital-acquired hyponatremia compared to hypotonic fluids 2, 3
• Multiple studies have demonstrated that isotonic fluids (sodium 140 mmol/L) result in fewer cases of hyponatremia than hypotonic fluids 2, 3

Special Clinical Considerations

• Fluid requirements may need adjustment in certain clinical scenarios:

  • Increased needs: fever, hyperventilation, hypermetabolism, gastrointestinal losses 1
  • Decreased needs: renal failure, congestive heart failure, mechanical ventilation 1

• In critically ill children, maintenance fluids can contribute approximately one-third of total fluid administration 4

• For children with septic shock, fluid management differs:

  • Initial bolus therapy (20 ml/kg) may be indicated 1
  • After resuscitation, transition to appropriate maintenance rates 1

Monitoring Recommendations

• Regular assessment of:

  • Fluid balance (intake and output) 1, 5
  • Serum electrolytes, particularly sodium 1, 2
  • Clinical signs of dehydration or fluid overload 1, 5

• Excessive fluid accumulation (>5%) is associated with worse outcomes in critically ill children 5

Common Pitfalls to Avoid

• Using hypotonic fluids for maintenance, which increases risk of hyponatremia 2, 3
• Failing to adjust maintenance rates in special clinical scenarios 1
• Not accounting for all sources of fluid intake (medications, nutrition) when calculating total daily fluid 5, 4
• Continuing maintenance rates without reassessment in changing clinical conditions 1