Paediatrics
Paediatric Maintenance Fluid
Daily maintenance fluid in children by weight (Holliday-Segar).
Education and reference only. Not a substitute for clinical judgement, local policy or product labelling. Always verify before clinical use. Values are calculated in your browser and never stored.
Background
This calculates a child's 24-hour maintenance fluid requirement using the Holliday-Segar method, commonly known as the 100/50/20 rule. It allocates 100 mL/kg for the first 10 kg of body weight, an additional 50 mL/kg for the next 10 kg, and 20 mL/kg for each kilogram above 20 kg. The method relates fluid needs to estimated energy expenditure and weight. The result, in millilitres over 24 hours, is a baseline maintenance requirement only.
Interpreting the result
The calculated volume represents ongoing maintenance needs and does not include correction of any existing dehydration or replacement of abnormal ongoing losses, which must be added separately. It assumes a well child with normal physiology, so the volume is adjusted for illness, fluid-overload states, renal or cardiac disease and other clinical factors. Isotonic maintenance fluids are now recommended, and electrolytes should be monitored. The figure is a starting estimate that requires clinical adjustment.
Worked example
For a 25 kg child: 100 mL/kg × 10 kg (1000 mL) + 50 mL/kg × 10 kg (500 mL) + 20 mL/kg × 5 kg (100 mL) = 1600 mL over 24 hours. Deficits and any ongoing losses would be added on top of this maintenance requirement.
Critical actions
A starting estimate only. Adjust for clinical status, deficits and ongoing losses, and follow local paediatric fluid guidance. Use isotonic fluids and check electrolytes per policy. Always double-check paediatric prescriptions.
Pearls / pitfalls
- Maintenance fluid does not include rehydration — existing deficits and ongoing losses must be calculated and added separately.
- Use isotonic fluids and monitor electrolytes; hypotonic fluids have caused dangerous hospital-acquired hyponatraemia in children.
- Reduce the volume in conditions with fluid retention or impaired excretion, such as some renal, cardiac or syndrome-of-inappropriate-ADH states.
- Paediatric prescriptions are weight-critical — always double-check the weight, calculation and prescription, ideally with a second checker.
Evidence & validation
Described by Holliday and Segar and adopted as the standard estimate of paediatric maintenance fluid. Modern guidance, including NICE, retains the volume calculation but recommends isotonic fluids and electrolyte monitoring to reduce the risk of hospital-acquired hyponatraemia.
Frequently asked questions
What is the 100/50/20 rule?
It is the Holliday-Segar method for daily maintenance fluid: 100 mL/kg for the first 10 kg, plus 50 mL/kg for the next 10 kg, plus 20 mL/kg for every kilogram above 20 kg.
Does maintenance fluid include rehydration?
No. Maintenance only covers ongoing baseline needs. Any existing dehydration deficit and abnormal ongoing losses, such as from vomiting or diarrhoea, must be calculated and added separately.
What type of fluid should be used?
Current guidance recommends isotonic maintenance fluids with appropriate glucose, because hypotonic fluids have been linked to hospital-acquired hyponatraemia. Electrolytes should be checked and monitored per local policy.
When should the volume be reduced?
Reduce maintenance volumes in conditions causing fluid retention or impaired water excretion, such as certain renal or cardiac disease and states of inappropriate ADH secretion, and in fluid-overloaded children.
Why is double-checking so important?
Paediatric fluid and drug calculations are weight-based, so a small error can have serious consequences. Independent double-checking of the weight, calculation and prescription is standard safe practice.
References
- Holliday MA, Segar WE. The maintenance need for water in parenteral fluid therapy. Pediatrics. 1957;19(5):823–832.
- NICE NG29: Intravenous fluid therapy in children and young people in hospital. 2015 (updated 2020).
About the creator
Holliday & Segar
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