Is the 4-2-1 rule used intraoperatively?

Yes, the 4-2-1 rule is used as the basis for intraoperative maintenance fluid rate in children. Fasting deficits and surgical losses are added separately. Many anesthesiologists use isotonic crystalloid at 5–10 mL/kg/hour as a simplified approach.

What are the limits of the 4-2-1 rule?

The formula was derived in healthy children at rest and does not account for fever, diarrhea, burns, or surgery-related fluid shifts. It should be adjusted for clinical context and regular reassessment of fluid balance.

4-2-1 Rule Intravenous Fluid (Hourly)

Compute hourly IV fluid rate using the 4-2-1 rule for pediatric maintenance: 4 mL/kg/hr for first 10 kg, plus 2 mL/kg/hr for next 10 kg, plus 1 mL/kg/hr for remaining weight.

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4-2-1 Rule Intravenous Fluid (Hourly)

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Frequently Asked Questions

Is the 4-2-1 rule used intraoperatively?

What are the limits of the 4-2-1 rule?