IV Fluids - for children beyond the newborn period

See also

Dehydration
Hyponatraemia 
Hypernatraemia 
Neonatal Intravenous Fluid

Background

• Whenever possible the enteral route should be used for fluids. These guidelines only apply to children who cannot receive enteral fluids.
• The safe use of IV fluid therapy in children requires accurate prescribing of fluid and careful monitoring
• Always check orders that you have written, and ensure that you double check on orders written by other staff when you take over the child's care
• Incorrectly prescribed or administered fluids are potentially very dangerous. More adverse events are described from fluid administration than for any other individual drug. If you have any doubt about a child's fluid orders - ask a senior doctor.
• Remember to check compatibility of intravenous fluid with any intravenous drugs that are being co-administered.

Assessment of fluid requirements: Unwell children (+/- abnormal hydration) 

How much Fluid?

If required, administer an initial bolus(es) of fluid to correct intravascular depletion then:

Maintenance plus
Deficit (dehydration guidelines), plus
Ongoing losses (dehydration guidelines)

Maintenance

This guideline should be used as a starting point and will need to be adjusted in ALL unwell children.

Generally 2/3 of maintenance rate should be used in unwell children unless they are dehydrated.  This is because they are likely to be secreting anti-diuretic hormone (ADH), so will need less fluid.  Children with meningitis or other acute CNS conditions will likely require additional fluid restriction – seek senior advice.

For fluid options in the dehydrated child see dehydration guidelines.

REMEMBER to consider deficit and ongoing losses - especially in severe gastroenteritis, if there are drain losses, ileostomies etc.

Which Fluid?

Some good fluid solutions for sick children include: 

Consider whether potassium is required in the fluid.  This should be avoided, if possible, unless premade fluid bags containing potassium are available.  Adding potassium to bags of fluid on the ward is a safety risk.

Hypotonic fluid (containing a sodium concentration less than plasma) is no longer recommended in children.  These fluids have been associated with morbidity/mortality secondary to hyponatraemia.  Fluids that should NOT be given include:

0.18% NaCl with 4% glucose +/- KCl 20 mmol/L (or 4% and 1/5 NS) should NOT be given

Monitoring

• All children on IV fluids should be weighed prior to the commencement of therapy, and daily afterwards. Ensure you request this on the treatment orders.
• Children with ongoing dehydration/ongoing losses may need 6 hourly weights to assess hydration status
• All children on IV fluids should have serum electrolytes and glucose checked before commencing the infusion (typically when the IV is placed) and again within 24 hours if IV therapy is to continue.
• For more unwell children, check the electrolytes and glucose 4-6 hours after commencing, and then according to results and the clinical situation but at least daily.
• Pay particular attention to the serum sodium on measures of electrolytes. If <135 mmol/L (or falling significantly on repeat measures) see Hyponatraemia. If >145 mmol/L (or rising significantly on repeat measures) see Hypernatraemia. 
• Children on iv fluids should have a fluid balance chart documenting input, ongoing losses and urine output.

Special fluids

Outside the newborn period, do not use these fluids apart from exceptional circumstances and check the serum sodium regularly

10% Dextrose
Used in neonates (sometimes with additional NaCl). Used in ICU for patients under 12 months (with 0.45% saline). Sometimes used by infusion in neonates and children with metabolic disorders. Check blood glucose regularly.

15-20% Dextrose
Very occasionally used by infusion in children with metabolic disorders. Check blood glucose regularly.

25% and 50% Dextrose
Rarely required in children, misuse can cause severe adverse events. Only used in discussion with senior staff as bolus or low volume infusions (1-2 ml/hr) to correct refractory hypoglycaemia.

Consider consultation with local paediatric team when:

• Unsure of which fluid/how much fluid to use
  
• Electrolyte abnormalities
  
• Using a non-standard 'special' fluid

Consider transfer when:

Children with severe electrolyte or glucose abnormalities.

Children requiring care above the level of comfort of the local hospital.

For emergency advice and paediatric or neonatal ICU transfers, call the Paediatric Infant Perinatal Emergency Retrieval (PIPER) Service: 1300 137 650.

Additional notes

Calculating maintenance fluid:

• daily fluid intake which replaces the insensible losses (from breathing, through the skin, and in the stool)
• allows excretion of the daily production of excess solute load (urea, creatinine, electrolytes, etc) in a volume of urine that is of an osmolarity similar to plasma.
• volume calculated per kilo.

100 mL / hour (2400 mL / day) is the normal maximum amount.

Note: There is often confusion about the difference between oral and iv fluid requirements for young infants. The water requirement is identical for both routes of administration. The relatively low energy density of milk means that infants need 150-200 mL / kg / day to obtain adequate nutrition. That is why they pass more dilute urine than older children.