What is the recommended maintenance fluid regimen for a pediatric patient?

Maintenance Fluids in Pediatric Patients

Use isotonic fluids (sodium 130-154 mEq/L) with appropriate dextrose and potassium at calculated maintenance rates for all hospitalized children 28 days to 18 years of age to prevent hyponatremia and reduce morbidity. 1

Fluid Composition

Tonicity

• Isotonic solutions (sodium 130-154 mEq/L) are strongly recommended over hypotonic fluids to reduce the risk of hospital-acquired hyponatremia, which has caused over 50 cases of neurologic morbidity including 26 deaths in children receiving hypotonic fluids 1, 2
• Acceptable isotonic solutions include 0.9% NaCl (154 mEq/L), PlasmaLyte (140 mEq/L), or Hartmann solution (131 mEq/L) 1
• The number needed to treat with isotonic fluids to prevent hyponatremia is 7.5, meaning for every 7-8 children treated with isotonic rather than hypotonic fluids, one case of hyponatremia is prevented 3

Balanced vs. Unbalanced Solutions

• Balanced solutions (lactated Ringer's or PlasmaLyte) should be favored over 0.9% NaCl to slightly reduce length of stay in both acutely and critically ill children 1
• Avoid lactate-buffered solutions in severe liver dysfunction to prevent lactic acidosis 1

Glucose Content

• Add sufficient glucose (typically 2.5-5% dextrose) to prevent hypoglycemia, guided by at least daily blood glucose monitoring 1
• Avoid excessive glucose in critically ill children to prevent hyperglycemia, using daily monitoring 1

Electrolyte Supplementation

• Add appropriate potassium based on clinical status and regular monitoring to avoid hypokalemia 1
• Typical requirements: 1-3 mmol/kg/day of sodium and 1-3 mmol/kg/day of potassium 1
• Insufficient evidence exists to recommend routine supplementation of magnesium, calcium, phosphate, vitamins, or trace elements unless deficiency signs are present 1

Fluid Volume Calculation

Standard Maintenance (Holliday-Segar Formula)

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

Volume Restriction in High-Risk Situations

• For children at risk of increased ADH secretion (pneumonia, CNS infections, postoperative state, dehydration): restrict to 65-80% of calculated Holliday-Segar volume to avoid fluid overload and hyponatremia 1
• For children with edematous states (heart failure, renal failure, hepatic failure): restrict to 50-60% of calculated volume 1
• Include ALL fluid sources in daily calculations: IV fluids, blood products, IV medications (infusions and boluses), line flushes, and enteral intake (excluding resuscitation and replacement fluids) 1

Monitoring Requirements

Frequency

• Reassess at least daily: fluid balance, clinical status, weight, and intake/output 1
• Monitor electrolytes regularly, especially sodium levels, at least daily 1
• Check blood glucose at least daily 1

Goals

• Avoid fluid overload and cumulative positive fluid balance to prevent prolonged mechanical ventilation and increased length of stay 1
• Maintain sodium levels between 135-144 mEq/L 1

Critical Pitfalls to Avoid

• Never use hypotonic fluids (sodium <130 mEq/L) as standard maintenance—this practice has directly caused fatal hyponatremic encephalopathy in children 1, 2
• Children are at particularly high risk for symptomatic hyponatremia due to larger brain-to-skull size ratio 2
• Common pediatric conditions (respiratory infections, CNS infections, postoperative states) trigger non-osmotic ADH release, making hypotonic fluids especially dangerous 1, 2
• Do not ignore "hidden" fluid sources—medications, flushes, and blood products contribute significantly to total daily intake 1
• Avoid continuing full maintenance rates in children with established fluid overload or oliguria 1

Route Preference

• Consider enteral or oral route for maintenance fluids in critically ill children with improving hemodynamic state, if tolerated, to reduce length of stay in term neonates 1