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Maintenance fluid rate (Holliday-Segar)

Hourly maintenance IV fluid rate by weight (4-2-1 rule).

Maintenance fluid rate (Holliday-Segar)
Weight
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When to use

  • Estimating baseline maintenance IV fluid rates, most often in paediatrics; add correction for any deficit and ongoing losses.

Formula

4-2-1 rule: 4 mL/kg/h for the first 10 kg, + 2 mL/kg/h for the next 10 kg, + 1 mL/kg/h for each kg above 20.

Pearls and pitfalls

  • Isotonic maintenance fluid is now preferred in children — hypotonic fluid at maintenance rates risks hyponatraemia.

References

  1. Holliday MA, Segar WE. The maintenance need for water in parenteral fluid therapy. Pediatrics. 1957;19(5):823–32.