Maintenance Fluid Rate for a 22.5 kg Pediatric Patient
For a 22.5 kg child, the maintenance fluid rate is 65 mL/hour (1560 mL/day) using the Holliday-Segar method, which calculates 4 mL/kg/h for the first 10 kg (40 mL/h) plus 2 mL/kg/h for the next 10 kg (20 mL/h) plus 1 mL/kg/h for the remaining 2.5 kg (2.5 mL/h). 1
Calculation Method
The standard approach uses the Holliday-Segar formula for maintenance fluid requirements 1:
- First 10 kg: 4 mL/kg/hour = 40 mL/hour
- Second 10 kg (10-20 kg): 2 mL/kg/hour = 20 mL/hour
- Remaining weight above 20 kg (2.5 kg): 1 mL/kg/hour = 2.5 mL/hour
- Total: 62.5 mL/hour (round to 65 mL/hour)
Alternatively expressed as daily volume: 100 mL/kg/day for first 10 kg (1000 mL) + 50 mL/kg/day for next 10 kg (500 mL) + 25 mL/kg/day for remaining 2.5 kg (62.5 mL) = 1562.5 mL/day 1
Fluid Composition
Use isotonic fluids (sodium 140 mmol/L) rather than hypotonic solutions for maintenance hydration in hospitalized children. 1 Large meta-analyses and randomized controlled trials have demonstrated that isotonic fluids significantly reduce the risk of hospital-acquired hyponatremia compared to traditional hypotonic maintenance fluids (sodium 35-77 mmol/L), which can lead to potentially fatal hyponatremic encephalopathy 1.
Electrolyte Requirements
For children in this weight range (6-12 years age group), the recommended daily parenteral electrolyte intake includes 1:
- Sodium: 1-3 mmol/kg/day
- Potassium: 1-3 mmol/kg/day
- Chloride: 2-4 mmol/kg/day
Important Clinical Considerations
This calculation applies to stable, hospitalized children requiring maintenance fluids—not children in shock or with significant dehydration. 2 For children presenting with shock, initial resuscitation requires 20 mL/kg boluses of isotonic crystalloid administered rapidly over 5-10 minutes, with reassessment after each bolus 2.
Monitor closely for fluid overload, especially in children with cardiac or renal disease. 1 Adjust fluid rates based on individual clinical circumstances including ongoing losses, underlying medical conditions, and response to therapy 1.
For children with specific conditions requiring fluid restriction (such as chronic lung disease), volumes may need to be reduced to 75-90 mL/kg/day initially, though this makes achieving adequate caloric intake more challenging 1.