IV Maintenance Fluid for a 4-Year-Old Child
Use isotonic balanced crystalloid solution (such as Lactated Ringer's or Plasma-Lyte) with 5% dextrose at a restricted rate of 65-80% of the Holliday-Segar calculation, with potassium supplementation once renal function is confirmed. 1, 2
Fluid Composition
Tonicity and Type:
- Isotonic balanced solutions are strongly recommended over hypotonic fluids to prevent hyponatremia, which can cause fatal encephalopathy 1
- Balanced solutions (Lactated Ringer's or Plasma-Lyte) are preferred over normal saline to reduce length of stay and avoid hyperchloremic acidosis 1, 2
- Avoid lactate-buffered solutions only if severe liver dysfunction is present 1
Glucose:
- Add 5% dextrose to prevent hypoglycemia, with at least daily blood glucose monitoring 1, 2
- Avoid excessive glucose to prevent hyperglycemia in critically ill children 1
Electrolytes:
- Add potassium 20-40 mEq/L (using 2/3 KCl and 1/3 KPO4) once renal function is confirmed and serum potassium is known 2
- For children aged 3-5 years, sodium requirement is 1-3 mmol/kg/day and potassium 1-3 mmol/kg/day 1
Volume Calculation
For a typical 4-year-old (approximately 16 kg):
Using the Holliday-Segar formula 1:
- First 10 kg: 100 mL/kg/day = 1000 mL
- Next 6 kg: 50 mL/kg/day = 300 mL
- Total = 1300 mL/day (54 mL/hour)
However, restrict to 65-80% of this volume 1, 2:
- Recommended rate: 845-1040 mL/day (35-43 mL/hour)
This restriction is critical because acutely ill children have increased ADH secretion, which impairs free water excretion and leads to hyponatremia and fluid overload if full maintenance rates are used 1, 2
Special Circumstances Requiring Further Restriction
Reduce to 50-60% of Holliday-Segar (650-780 mL/day or 27-33 mL/hour) if the child has: 1, 2
- Heart failure
- Renal failure
- Hepatic failure
- Established fluid overload
Monitoring Requirements
Daily minimum assessments: 1, 2
- Fluid balance calculation (intake minus output)
- Daily weight measurement
- Serum sodium and electrolytes
- Blood glucose monitoring
- Clinical assessment for signs of fluid overload (edema, respiratory distress)
Calculate total fluid intake including: 1, 2
- All IV fluids and medications
- Blood products
- Arterial/venous line flushes
- Enteral intake
- This prevents "fluid creep" where unaccounted fluids lead to overload
Critical Pitfalls to Avoid
Do not use hypotonic solutions (0.18% or 0.45% saline) for routine maintenance, as they significantly increase the risk of life-threatening hyponatremia 1, 2, 3
Do not apply full Holliday-Segar rates to acutely ill children, as this leads to fluid overload and hyponatremia due to elevated ADH secretion 1, 2
Do not delay electrolyte monitoring - check at least daily, more frequently if the child is unstable or has abnormal baseline values 1, 2
Do not forget to account for all fluid sources when calculating daily intake, including medication carriers and line flushes 1, 2
Practical Example Order
For a 16 kg, 4-year-old child without heart/renal/liver failure:
"Lactated Ringer's with 5% dextrose at 40 mL/hour (70% of maintenance). Add 20 mEq KCl per liter once urine output confirmed and serum potassium <5.0 mEq/L. Monitor daily weights, strict intake/output, and check basic metabolic panel daily." 1, 2