Starting IV Fluids in Pediatric Patients
Use isotonic balanced solutions (like Plasma-Lyte or Hartmann's/Lactated Ringer's) with 5% dextrose and appropriate potassium supplementation for maintenance IV fluids in children aged 28 days to 18 years. 1
Fluid Composition
Tonicity: Isotonic Solutions (Level A Evidence)
- Use isotonic fluids with sodium concentration 130-154 mEq/L (similar to 0.9% NaCl, Plasma-Lyte, or Hartmann's solution) 2, 1
- This significantly reduces hyponatremia risk with a number needed to treat of 7.5 to prevent any hyponatremia and 27.8 to prevent moderate hyponatremia 2
- Isotonic fluids do NOT increase hypernatremia risk 2
Balanced vs Non-Balanced Solutions
Prefer balanced solutions (Plasma-Lyte, Hartmann's/Lactated Ringer's) over 0.9% NaCl 1:
- Balanced solutions slightly reduce length of stay (Level A evidence for acute illness, Level B for critical illness) 1
- They prevent hyperchloremic acidosis compared to normal saline
- Caveat: Avoid lactate-buffered solutions in severe liver dysfunction due to lactic acidosis risk 1
Glucose Content
- Add 5% dextrose to prevent hypoglycemia 1
- Monitor blood glucose at least daily 1
- In critically ill children, avoid excessive glucose to prevent hyperglycemia (Level B evidence) 1
Electrolyte Additions
- Add potassium based on clinical status and regular monitoring to prevent hypokalemia 1
- No routine supplementation needed for calcium, magnesium, phosphate, vitamins, or trace elements unless deficiency signs present 1
Fluid Volume Calculation
Standard Approach: Modified Holliday-Segar
Restrict to 65-80% of traditional Holliday-Segar calculation in most acute/critically ill children 1:
- Traditional Holliday-Segar: 100 mL/kg for first 10 kg, 50 mL/kg for next 10 kg, 20 mL/kg thereafter
- Use 65-80% of this calculated volume to prevent fluid overload and hyponatremia in children at risk of increased ADH secretion 1
High-Risk Populations Requiring Further Restriction
Restrict to 50-60% of Holliday-Segar in children with 1:
- Heart failure
- Renal failure
- Hepatic failure
- Other edematous states
What Counts as "Total Fluid"
Include ALL of the following in your daily fluid calculation 1:
- IV maintenance fluids
- Blood products
- All IV medications (infusions AND boluses)
- Arterial and venous line flush solutions
- Enteral intake
- Exclude: Resuscitation fluids, replacement fluids, massive transfusion
Monitoring Requirements
Reassess at least daily 1:
- Fluid balance (input/output)
- Clinical status (signs of fluid overload or dehydration)
- Electrolytes, especially sodium
- Serum glucose
Avoid cumulative positive fluid balance to prevent prolonged mechanical ventilation and increased length of stay 1
Important Exclusions
These guidelines DO NOT apply to 2:
- Neonates <28 days old or in NICU
- Adolescents >18 years
- Neurosurgical disorders
- Congenital/acquired cardiac disease
- Hepatic disease
- Cancer
- Renal dysfunction
- Diabetes insipidus
- Voluminous watery diarrhea
- Severe burns
Practical Implementation
Ideal prescription example: Plasma-Lyte or Hartmann's solution with 5% dextrose plus 20 mEq/L KCl, running at 65-80% of calculated Holliday-Segar rate
Common pitfall: The 2022 ESPNIC guidelines 1 are more recent than the 2018 AAP guidelines 2 and provide additional nuance on balanced solutions and volume restriction, though both strongly agree on isotonic fluids. The ESPNIC guidelines extend recommendations to include balanced solutions and specific volume restrictions that the AAP guidelines did not address.
Reality check: Ready-to-use balanced isotonic solutions with glucose are inconsistently available across regions 3. If unavailable, 0.9% NaCl with 5% dextrose and KCl is an acceptable alternative, though balanced solutions are preferred when available.