Maintenance fluid calculator for pediatric IV fluids

The two most used pediatric maintenance methods are Holliday–Segar (daily water requirements) and the 4–2–1 rule (hourly rate). This tool computes both and rounds for display while preserving exact internal math.

• Holliday–Segar (daily mL): 100 mL/kg for 0–10 kg; 1,000 + 50 mL/kg for 10–20 kg; 1,500 + 20 mL/kg for >20 kg.
• 4–2–1 (hourly mL/h): 4 mL/kg/h for first 10 kg; 2 mL/kg/h for second 10 kg; 1 mL/kg/h for each kg >20.

Example: 22 kg child → Daily = 1,500 + 20×2 = 1,540 mL/day; Hourly = 4×10 + 2×10 + 1×2 = 62 mL/h.

1. Confirm current weight (kg), indication, and current hemodynamic status before calculating maintenance.
2. Calculate baseline maintenance (Holliday-Segar and 4-2-1) and document the selected operational rate.
3. Choose fluid composition per institutional policy (usually isotonic; add dextrose/potassium when indicated).
4. Account separately for deficits and ongoing losses rather than inflating baseline maintenance rate.
5. Reassess vitals, urine output, fluid balance, and electrolytes at planned intervals and adjust promptly.

The 2018 AAP guideline recommends isotonic maintenance solutions for most hospitalized children to reduce hyponatremia risk. Dextrose and potassium chloride are often added based on clinical context and labs. Always follow your institution’s policy and monitor sodium, potassium, and glucose.

• Screen for SIADH risk, renal/cardiac disease, and CNS pathology before selecting composition.
• Consider dextrose for infants and children at risk of hypoglycemia; add potassium only after verifying adequate urine output and normal K.

• Fever/insensible losses: May increase needs modestly—adjust to clinical response and hydration status.
• Neonates: Use NICU protocols; maintenance needs vary rapidly with day of life and phototherapy.
• Obesity: Some centers use adjusted body weight for maintenance—confirm local policy before applying caps.
• Deficits and ongoing losses: Replace separately (e.g., bolus for dehydration, NG/ostomy losses) and reassess frequently.

• Using pounds instead of kilograms for weight entry.
• Applying maintenance rates to deficit replacement instead of separating those orders.
• Failing to reassess electrolytes after composition changes or significant fluid shifts.
• Continuing default rates despite changing urine output, perfusion, or sodium trends.

• Worsening perfusion, oliguria, rising lactate, or hemodynamic instability despite maintenance plan.
• Rapid sodium/glucose shifts or concerning electrolyte derangements after fluid adjustments.
• Ongoing losses exceeding replacement assumptions or uncertain deficit estimation.
• Mismatch between calculated maintenance rate and bedside clinical trajectory.

• Weight used, selected maintenance method, and calculated mL/h.
• Fluid composition and rationale (including dextrose/potassium decisions).
• Deficit and ongoing loss replacement plan documented separately.
• Objective reassessment timing for vitals, urine output, balance, and labs.
• Escalation trigger thresholds and responsible covering team.

• Stable child after initial order: bedside reassessment within 4-6 hours and daily chemistry per institutional routine.
• Active fluid shifts, diuretics, or composition changes: reassess intake/output and electrolytes within 4-8 hours.
• Clinical instability, evolving AKI, or sodium trajectory concern: same-shift reassessment with tighter lab cadence.

• Prefer isotonic maintenance in most hospitalized children unless a specific indication supports alternative tonicity.
• Avoid untracked free-water exposure from concurrent infusions when interpreting sodium trends.
• After composition changes, pair sodium trend review with neurologic status and fluid balance rather than sodium alone.
• Escalate early for rapid sodium movement, seizure risk context, or unclear intake accounting.

• Intake breakdown by source: maintenance, bolus, medication carrier volumes, and enteral intake.
• Output trend with urine mL/kg/hr, stool/emesis, and measurable drain losses.
• Net balance trend versus perfusion findings and weight change.
• Latest sodium, potassium, glucose, bicarbonate, and creatinine trend after composition or rate changes.
• Documented next review time and responsible covering clinician.

If maintenance strategy is not matching bedside trajectory, package the key data below before escalating. This reduces handoff delay and duplicate recalculation.

• Weight/time stamp used for calculation and both Holliday-Segar + 4-2-1 outputs.
• Active fluid orders (maintenance, bolus, replacement) with exact rates and start times.
• Objective trajectory: vitals, urine output, net balance, and relevant lab changes.
• Current concern (e.g., sodium drift, oliguria, worsening perfusion) and actions already taken.
• Requested decision point for senior review (composition change, rate change, bolus strategy, or higher-acuity transfer).

• 5 kg: Daily 500 mL; Hourly 20 mL/h → "Isotonic maintenance at 20 mL/h; adjust electrolytes per labs."
• 12 kg: Daily 1,100 mL; Hourly 28 mL/h → "Isotonic maintenance at 28 mL/h; monitor Na/K/Glucose."
• 22 kg: Daily 1,540 mL; Hourly 62 mL/h → "Isotonic maintenance at 62 mL/h; reassess q6–8h."

• Dehydration in Children Calculator — use when deficits, ORS failure, or IV rehydration planning matter more than baseline maintenance alone.
• Pediatric Fluids, Electrolytes & Renal Calculators — use when maintenance fluid orders need renal, electrolyte, or broader fluids workflow context.
• Pediatric Transfusion Volume (PRBC) — use when fluid planning overlaps with anemia, blood loss, or transfusion decisions.
• Pediatric calculators hub — browse the full bedside calculator set when the child needs a different workflow entirely.

• Consider isotonic maintenance fluids in most hospitalized children (AAP 2018). Add dextrose/K per policy.
• Special populations (neonates, renal, cardiac, SIADH) require tailored plans and close monitoring.
• Reassess frequently; adjust for deficits, ongoing losses, and hemodynamics.

• Holliday MA, Segar WE. The maintenance need for water in parenteral fluid therapy. Pediatrics. 1957.
• AAP Clinical Practice Guideline: Maintenance Intravenous Fluids in Children (2018)
• Intravenous maintenance fluids revisited (review)