Intravenous (IV) fluids for children. Follow specialised fluid guidance for:

• Neonates
• Trauma, including burns
• Severe electrolyte abnormalities, including hypernatraemia, hyponatraemia, diabetic ketoacidosis and pyloric stenosis
• Cardiac, liver and renal impairment
• Inborn errors of metabolism (known or suspected)
• Oncology hyperhydration

See also

Resuscitation: Care of the seriously unwell child
Dehydration
Maintenance fluids calculator

Key points

1. Intravenous (IV) fluid therapy should be treated as a prescribed medication with the indications, contraindications and adverse effects considered. Whenever possible, the enteral route should be used
2. In most situations, the preferred maintenance fluid type is sodium chloride 0.9% with glucose 5% +/- potassium
3. The majority of unwell children will retain water and require less than full maintenance fluids eg 2/3 maintenance
4. Children receiving IV fluids should have serial weight and electrolyte measurements
5. When treating dehydration (ie replacing a fluid deficit) with IV fluids, most children should have a maximum of 5% fluid deficit replaced over 24 hours (in addition to maintenance), and then be reassessed to determine ongoing need for IV fluids

Background

This guideline only applies to children aged 1 month to 18 years who cannot receive enteral fluids

• Fluids with a similar sodium concentration to plasma are most appropriate
• Safe use of IV fluid in children requires careful prescribing and monitoring
• Check the compatibility of IV fluid with any IV drugs that are being co-administered

Assessment

Red flags

• Abnormal serum sodium <135 mmol/L or >145 mmol/L or significant change of >0.5 mmol/L/hr on a repeat measure. See hyponatraemia or hypernatraemia and notify senior clinician
• Consider increased antidiuretic hormone (ADH) secretion, especially with acute CNS and pulmonary conditions, although any unwell child is at risk
• Short gut or other significant gastrointestinal pathology
• Fluid resuscitation >20 mL/kg required
• Situations where specialised fluid management is required. See list of specialised fluid guidance above

Examination

Hydration status

• Assess for dehydration
• Signs of fluid overload including oedema (eg periorbital, genital, sacral, peripheral) should also be evaluated, especially in children already receiving IV fluid treatment

Weight and fluid balance

• Repeated weights are the best measure of fluid status. All children on IV fluids should be weighed at the start of treatment and then at least once daily
• Children with severe dehydration or ongoing losses need to be weighed more often
• Document intake/inputs and ongoing losses (including urine output), with at least 12 hourly subtotals

Management

Investigations

Serum electrolytes and glucose

• All children should have serum electrolytes and glucose checked before starting IV fluid treatment, and at least every 24 hours if IV fluids are continued at more than 50% maintenance
• For more unwell children and children with large fluid losses or abnormal electrolytes, check the electrolytes and glucose 4-6 hours after starting fluid therapy, and then according to the clinical situation

Treatment

Approach to IV fluid prescription

Resuscitation fluid

For treatment of shocked children, see Resuscitation: Care of the seriously unwell child

Treat shock with bolus IV fluids to restore circulatory volume:

Give a bolus of 10-20 mL/kg of sodium chloride 0.9% as fast as possible, and reassess to determine if additional IV fluid is required

Do not include this fluid volume in subsequent calculations

• Reassess circulation after each bolus
• Give additional boluses 10-20 mL/kg as required
• If ≥20 mL/kg in fluid boluses, involve a senior clinician
• If ≥40 mL/kg in fluid boluses, inotropes should be considered

Alternative resuscitation fluids

• Packed red blood cells 10 mL/kg first-line fluid replacement in trauma
• Plasma-Lyte 148, Hartmann's solution or albumin may sometimes be used as resuscitation fluid on senior advice
• Glucose containing fluids should not be given as a fluid bolus for shock. If treating hypoglycaemia, see Hypoglycaemia

Choice of fluid

Maintenance fluids

Sodium chloride 0.9% with glucose 5% is the most commonly used fluid type for IV maintenance fluids

• Glucose (usually 5%) should be included in maintenance fluids for most children, especially those with no other source of glucose eg nil by mouth

Alternative maintenance fluids

• Plasma-Lyte 148 with glucose 5% contains 5 mmol/L potassium and less chloride than sodium chloride 0.9% with glucose 5%. It may be used in children with hyperchloraemia and acidosis
• Hartmann's solution with glucose 5% is not often used as a maintenance fluid in children, and requires checking for drug incompatibility eg ceftriaxone
• See table in Additional Notes section below on Electrolyte content of intravenous fluids
• Availability of premade bags and local guidelines may vary. Always follow local injectable guidelines

Maintenance fluid additives

Calculating fluid rate

Maintenance fluid rates

Hourly fluid rates can be calculated using this Maintenance fluids calculator

Full maintenance fluid rates may be calculated using the table below as a starting point. Consider using ideal body weight to calculate maintenance fluid rates. This calculation applies for well children only. Fluid rates need to be adjusted for all unwell children

This calculation estimates a volume that will maintain hydration in healthy children while

• Accounting for insensible losses (from breathing, through the skin, and in stool)
• Allows for excretion of the daily excess solute load (urea, creatinine, electrolytes, etc) in a volume of urine with similar osmolarity to plasma

Note

• The maintenance fluid requirement calculation in this table applies to all ages including young infants (excluding neonates and premature babies)
• Babies need a higher volume of enteral milk (150-180 mL/kg/day) to meet nutritional and growth requirements, but this higher volume should not be used as a basis for IV fluid prescribing
• IV fluid prescribing for an infant should be based on the water requirement (ie 100 mL/kg/day up to 10 kg) and then adjust as clinically indicated (eg restrict to 2/3 maintenance)

Fluid restriction

2/3 maintenance rates should be used in the majority of unwell children unless they are dehydrated. Unwell children are likely to secrete high levels of antidiuretic hormone (ADH), so will need less fluid to avoid water overload and hyponatraemia

Children with the following conditions are at high risk of excess ADH secretion and may require further fluid restriction, seek senior advice:

• Acute CNS conditions (meningitis, tumours, head injuries)
• Pulmonary conditions (pneumonia, bronchiolitis, mechanical ventilation)
• Post-operatively
• Trauma

Replacement of fluid deficit

Previously, a formula based on % dehydration has been used to calculate the rate at which fluid deficits should be replaced. However, clinician estimates of % dehydration have been shown to be unreliable

In most children, a constant rate of IV fluids based on premorbid weight can be used, and only the duration of IV fluids is adjusted. Suggested hourly fluid rates based on weight (see table below) are based on the rate needed to replace a 5% fluid deficit over 24 hours + maintenance fluid rate

To determine the duration of IV fluids at this rate:

• For children with ≤5% dehydration, replace deficit in the first 24 hours
• For children with >5% dehydration, replace deficit over a longer period eg for 10% dehydration, replace 5% deficit in the first 24 hours, then 5% in the following 24 hours

A worked example for IV rehydration is in Additional Notes section below

Serial clinical assessment of hydration status must be made at regular intervals for all children with dehydration. If electrolytes are deranged, consult senior clinician and relevant guideline, and consider slower replacement of deficit

Suggested hourly IV fluid rates for a dehydrated child

Ongoing fluid losses

Abnormal ongoing losses should be measured and replaced if clinically indicated, based on each previous hour (if significant) or 4-hour period (eg a 200 mL loss over the previous 4 hours is replaced by giving 50 mL/hr for the next 4 hours)

Gastrointestinal tract losses are commonly replaced with sodium chloride 0.9% + potassium chloride 20 mmol/L

Safety considerations

• Strict fluid balance charts should be used in any child receiving IV fluids
• Where possible, always use premixed bags of fluid. Availability of premade bags and local guidelines may vary. Always follow local injectable guidelines
• Using a burette in small children can reduce the risk of large volumes being inadvertently administered
• IV pumps should be set with an hourly volume to be infused. Reset each hour with the volume infused checked
• Inspect cannula site regularly for signs of extravasation. See Peripheral extravasation injuries
• Monitor BGL and electrolytes regularly. See Investigations section above

Consider consultation with local paediatric team when

• Unsure of which/how much fluid to use
• Electrolyte abnormalities requiring intervention
• Using a non-standard fluid
• Significant co-morbidities are present
• Fluid resuscitation >20 mL/kg required

Consider transfer when

Children with severe electrolyte or glucose abnormalities
Shock requiring ≥40 mL/kg IV fluid boluses
Children requiring care above the level of comfort of the local hospital

For emergency advice and paediatric or neonatal ICU transfers, see Retrieval Services

Additional notes/other considerations

Additional resources

Emergency medication and resuscitation resources

Maintenance fluid calculator

Worked example for fluid replacement

An infant with severe gastroenteritis requires fluid rehydration and is not tolerating enteral fluids. A decision is made to proceed with IV fluid treatment. The infant weighed 10 kg prior to this illness but her current weight is 9 kg. She has clinical signs consistent with severe dehydration

In the first 24 hours, replace 5% dehydration as per suggested rehydration rates in table above. For this infant that is 500 mL (ie 500 mL ÷ 24 = 20.5 mL/hr). Replace the remaining deficit (another 500 mL ÷ 24 = 20.5 mL/hr) if still indicated after clinical reassessment, over the following 24 hours

Next, calculate the infant's maintenance fluid requirement and check it using the calculator:

Hourly maintenance rate (mL/hr) = 4 x pre-morbid weight (kg) = 40 mL/hr

The starting total hourly fluid rate = 40 mL/hr + 20.5 mL/hr = 60.5 mL/hr

A re-assessment of the child's fluid status, including any ongoing losses, should be completed within 6 hours

Electrolyte content of intravenous fluids

Last updated January 2026

Reference list

1. Brossier DW, Goyer I, Verbruggen SCAT et al. Intravenous maintenance fluid therapy in acutely and critically ill children: state of the evidence. The Lancet Child Adolesc Health. March 2024. Pg 236-244 
2. Children’s Health Queensland Hospital and Health Service. Intravenous fluid bolus. 2023 https://www.childrens.health.qld.gov.au/__data/assets/pdf_file/0033/179709/paediatric-fluid-bolus.pdf (viewed 12 December 2024) 
3. Children’s Heath Queensland Hospital and Health Service. Intravenous maintenance fluids. 2023 https://www.childrens.health.qld.gov.au/__data/assets/pdf_file/0032/179708/paediatric-intravenous-maintenance-fluids.pdf (viewed 12 December 2024)
4. Friedman JN, Beck CE, DeGroot J et al. Comparison of isotonic and hypotonic intravenous maintenance fluids. JAMA Pediatr. May 2015 vol 169 pg 445-451 
5. Maitland K, Kiguli S, Opoka RO et al. 2011 ‘Mortality after fluid bolus in African children with severe infection’. N Engl J Med. vol 364 pg 2483-2495 
6. McNab S, Duke T, South M, et al. 2015 ‘140 mmol/L of sodium versus 77 mmol/L of sodium in maintenance intravenous fluid therapy for children in hospital (PIMS): a randomised controlled double-blind trial’. Lancet vol 385 pg 1190-1197 
7. McNab S. Intravenous maintenance fluid therapy in children. Journal of Paediatrics and Child Health 2016 vol 52 pg 137-140 http://www.paedsportal.com/application/files/1414/6631/5000/McNab_IV_maintenance_fluids_JPCH_2016.pdf (viewed 12 December 2024) 
8. National Institute for Health and Care Excellence (NICE) 2020, Intravenous Fluid Therapy in Children and Young People in Hospital https://www.nice.org.uk/guidance/ng29 (viewed 12 December 2024) 
9. Perth Children’s Hospital. Intravenous fluid therapy. 2022 https://pch.health.wa.gov.au/For-health-professionals/Emergency-Department-Guidelines/Intravenous-fluid-therapy (viewed 12 December 2024) 
10. Somers MJ. Maintenance intravenous fluid therapy in children. UpToDate 2024 https://www.uptodate.com/contents/maintenance-intravenous-fluid-therapy-in-children (viewed 12 December 2024) 
11. Starship Hospital 2018, Intravenous Fluids, Starship Hospital, viewed 25 May 2020, https://www.starship.org.nz/guidelines/intravenous-fluids/ (viewed 12 December 2024) 
12. Steiner MJ, DeWalt DA, Byerley JS. Is This Child Dehydrated? JAMA. 2004;291(22):2746–2754 
13. Weinberg L, Collins N, Van Mourik K et al. Plasma-Lyte 148: A clinical review. World Journal of Critical Care Medicine vol. 5 pg 235-250.