Maintenance Fluid Management in Hospitalized Children

Standard Maintenance Requirements

• A child weighing 25 kg requires approximately 1 600 mL per day (≈ 65 mL/h) of isotonic maintenance fluid under standard, euvolemic conditions. 1
• The Holliday‑Segar formula (100 mL/kg for the first 10 kg, 50 mL/kg for the next 10 kg, and 25 mL/kg for weight above 20 kg) yields a total of about 1 625 mL/day, which is rounded to 1 600 mL/day for practical use. 1
• This formula remains the standard method for calculating children’s maintenance water needs based solely on weight. 1

Fluid Composition Recommendations

• Isotonic solutions containing sodium 130–154 mEq/L, with added dextrose (2.5–5 % glucose) and potassium as needed, should be used for all hospitalized children to prevent hospital‑acquired hyponatremia. 2
• Balanced isotonic crystalloids (e.g., lactated Ringer’s or PlasmaLyte) are preferred over 0.9 % NaCl because they modestly shorten length of stay and avoid hyperchloremic metabolic acidosis. 2
• Glucose 2.5–5 % should be incorporated into maintenance fluids to prevent hypoglycemia, with daily glucose monitoring. 2
• Potassium supplementation should be individualized based on the child’s clinical status and monitored regularly to avoid hypokalemia. 2

Adjustments for Specific Clinical Situations

• High‑risk ADH‑secretion states (e.g., pneumonia, central nervous system infection, postoperative state, dehydration) – reduce maintenance volume to 65–80 % of the calculated amount (≈ 1 040–1 280 mL/day). 2
• Mechanical ventilation – reduce to 65–80 % of calculated volume (≈ 1 040–1 280 mL/day). 1
• Temperature‑controlled environments – reduce to 65–80 % of calculated volume (≈ 1 040–1 280 mL/day). 1
• Renal failure – reduce to 50–60 % of calculated volume (≈ 800–960 mL/day). 1
• Fever, hyperventilation, hypermetabolism, or ongoing gastrointestinal losses – increase fluid volume above the standard calculation as clinically indicated. 1

Total Daily Fluid Accounting

• The calculated maintenance volume must incorporate all fluid sources, including:
  • Intravenous maintenance fluids
  • Blood products
  • Intravenous medications (both infusions and boluses)
  • Arterial and venous line flush solutions
  • Enteral intake
• Replacement fluids for acute losses or massive transfusion are not included in the maintenance calculation. 2

Safety Considerations

• Avoid hypotonic fluids (sodium < 130 mEq/L) for routine maintenance, as they are associated with fatal hyponatremic encephalopathy. 2
• Account for “hidden” fluid sources (medications, flushes, blood products) to prevent inadvertent fluid overload. 2
• Do not continue full maintenance rates without reassessment in children who develop fluid overload, oliguria, or whose clinical condition changes. 2

Pediatric Maintenance Fluid Calculation Guidelines

Basic Calculation Method

• The Holliday and Segar formula calculates maintenance fluid requirements based on weight alone and is still considered appropriate in the clinical setting 3, 4
• For hourly rates, this translates to:
  • 4 ml/kg/hour for the first 10 kg 5
  • 2 ml/kg/hour for the next 10 kg (10-20 kg) 5
  • 1 ml/kg/hour for each kg above 20 kg 5

Fluid Composition Recommendations

• Isotonic fluids should be used as intravenous maintenance fluid therapy in acutely and critically ill children, especially during the first 24 hours 3
• Glucose provision should be included in sufficient amounts to prevent hypoglycemia but not excessive to avoid hyperglycemia, with monitoring at least daily 6
• Appropriate potassium supplementation should be added based on the child's clinical status and regular potassium monitoring 6
• Chloride intake should be slightly lower than the sum of sodium and potassium intakes to avoid iatrogenic metabolic acidosis 7

Special Clinical Considerations

• For children at risk of increased antidiuretic hormone (ADH) secretion, restrict maintenance fluid volume to 65-80% of the calculated Holliday and Segar formula to avoid fluid overload and hyponatremia 6
• For children with heart failure, renal failure, or hepatic failure, restrict maintenance fluid volume to 50-60% of the calculated volume 6, 8
• The total daily amount of maintenance fluid therapy should include IV fluids, blood products, all IV medications, line flush solutions, and enteral intake 6
• Avoid fluid overload and cumulative positive fluid balance to prevent prolonged mechanical ventilation and increased length of stay 6

Monitoring Recommendations

• Reassess acutely and critically ill children at least daily regarding fluid balance and clinical status 6
• Regularly monitor electrolytes, especially sodium levels 6
• Individual patient needs may deviate markedly from the recommended ranges depending on clinical circumstances such as fluid retention, dehydration, or excessive water losses 3, 4

Pediatric Maintenance Fluid Management Guidelines

Calculation Method

• The Holliday‑Segar formula remains the standard method for determining maintenance fluid requirements in children. 9

Recommended Fluid Composition

• Isotonic solutions containing sodium 130–154 mEq/L combined with 2.5–5 % dextrose are recommended as the routine maintenance fluid. 9
• Balanced isotonic crystalloids (e.g., lactated Ringer’s or PlasmaLyte) are preferred over 0.9 % NaCl to reduce the risk of hyperchloremic acidosis and modestly shorten hospital length of stay. 9
• Potassium should be added according to the patient’s clinical status and monitored regularly to avoid hypokalemia. 9
• Glucose supplementation is advised to prevent hypoglycemia, with at least daily blood‑glucose checks. 9

Clinical Adjustments to Maintenance Rate

• Reduce to 65–80 % of the calculated volume (≈35–43 mL/h for a 17‑kg child) in conditions associated with high antidiuretic hormone secretion such as pneumonia, central nervous system infection, postoperative state, or dehydration. 9
• Reduce to 50–60 % of the calculated volume (≈27–32 mL/h for a 17‑kg child) in the presence of renal failure. 9
• Reduce to 50–60 % of the calculated volume for heart failure or hepatic failure. 9

Total Fluid Accounting

• The maintenance rate must incorporate all fluid inputs, not only the primary intravenous line. 9
  
  • Blood product administration counts toward total fluid intake. 9
  • All intravenous medications (both continuous infusions and bolus doses) are included. 9
  • Arterial and venous line flush solutions are part of the fluid balance. 9
  • Enteral nutrition/fluids are also considered in the total volume. 9

Monitoring Requirements

• Reassessment should occur at least daily, evaluating:
  • Overall fluid balance and clinical status. 9
  • Serum sodium concentration to detect hyponatremia. 9
  • Signs of fluid overload or dehydration. 9

Safety Considerations

• Hidden fluid sources from medications and line flushes must be accounted for to avoid inadvertent fluid overload, which can prolong mechanical ventilation and increase length of stay. 9
• The maintenance rate should be revised promptly if the patient develops oliguria, fluid overload, or any change in clinical condition. 9