Can a 5-Year-Old Receive a 475 mL Bolus of Normal Saline?
Yes, a 475 mL bolus of normal saline can be safely administered to a 5-year-old child if given appropriately as divided boluses (typically 10-20 mL/kg per bolus) with mandatory reassessment after each bolus, rather than as a single rapid infusion.
Weight-Based Calculation
Assuming an average 5-year-old weighs approximately 18-20 kg:
- Standard initial bolus: 20 mL/kg = 360-400 mL 1
- Maximum recommended in first hour: 40-60 mL/kg = 720-1200 mL 2, 1
- Your proposed 475 mL falls within safe limits but must be administered correctly
Critical Administration Protocol
Divide into sequential boluses of 10-20 mL/kg each (180-400 mL per bolus for a 20 kg child), administered over 15-20 minutes per bolus, not 5-10 minutes 3:
- A 2017 randomized controlled trial demonstrated that children receiving fluid boluses over 5-10 minutes had significantly higher risk of mechanical ventilation compared to those receiving boluses over 15-20 minutes (57% vs 36% at 6 hours; RR 0.62,95% CI 0.39-0.99) 3
- This challenges older guidelines recommending 5-10 minute boluses 2
Mandatory reassessment after each bolus before administering additional fluid 1:
- Heart rate (should decrease toward normal)
- Blood pressure (should improve)
- Capillary refill time (should improve to <2 seconds)
- Mental status (should improve)
- Urine output (should increase to >0.5 mL/kg/h)
- Signs of fluid overload (hepatomegaly, pulmonary edema)
Clinical Context Matters
For septic shock or severe dehydration in systems with intensive care available:
- Administer up to 40-60 mL/kg (720-1200 mL for a 20 kg child) in the first hour as divided boluses 2, 1
- Your 475 mL represents approximately 24-26 mL/kg, which is reasonable as initial resuscitation
For anaphylaxis:
- Children should receive up to 30 mL/kg in the first hour 2
- 475 mL would be appropriate for a 16-20 kg child
Stop immediately if signs of fluid overload develop 2, 1:
- New or worsening hepatomegaly
- Clinical signs of pulmonary edema
- Deteriorating oxygenation
Fluid Type Selection
Use balanced/buffered crystalloids (Ringer's lactate) rather than 0.9% saline when possible 2, 1:
- A 2023 multicenter RCT showed balanced crystalloids reduced new/progressive acute kidney injury compared to 0.9% saline (21% vs 33%; RR 0.62, p<0.001) 4
- However, 0.9% saline remains acceptable if balanced crystalloids are unavailable 1
Critical Volume Thresholds
Never exceed 60 mL/kg/day of total crystalloid (1200 mL for a 20 kg child) 1:
- Volumes exceeding this are associated with significantly worse outcomes in pediatric patients
- Fluid overload at 10% above baseline should trigger intervention in critically ill children 5
If hypotension persists after 40-60 mL/kg, initiate vasopressors rather than continuing aggressive fluid resuscitation 6:
- Norepinephrine is the first-line vasopresor
- Some children may require up to 200 mL/kg during initial resuscitation, but this requires intensive monitoring 6
Special Populations Requiring Caution
Reduce volumes and monitor closely in children with 1:
- Congestive heart failure
- Chronic renal disease
- Hepatic failure
These patients cannot tolerate standard resuscitation volumes and require individualized fluid management with advanced hemodynamic monitoring 2, 1.
Common Pitfalls to Avoid
- Never administer the entire 475 mL as a single rapid bolus without reassessment 1
- Never use hypotonic fluids (5% dextrose in water) for resuscitation—this has caused fatal outcomes 7
- Never delay reassessment between boluses, as this is when fluid overload develops 2, 1
- Never rely solely on clinical signs to categorize shock type without objective measures 6