See also

Intravenous fluids
Dehydration
Hypernatraemia
Hyponatraemia
Pyloric stenosis
Recognition of the seriously unwell neonate and young infant

Key points

1. This guideline provides advice for neonates above 32 weeks and outside of a neonatal intensive care setting
2. Whenever possible, the enteral route should be used
3. For neonates greater than 32 weeks and 1500g requiring short term intravenous (IV) therapy, the preferred fluid type is glucose 10% in the first 24-48 hours of life, followed by fluids that contain sodium and potassium
4. Parenteral nutrition is preferred for any neonate needing IV fluids >5 days
5. If a neonate weighs less than birth weight, utilise birth weight in all fluid calculations, unless specified

Background

• The goal of fluid administration is to maintain hydration and achieve biochemical balance, particularly to avoid hypoglycaemia and hyponatraemia
• For all neonates, start enteral feeds as soon as possible
• The percentage of Total Body Water (TBW) changes with increasing gestational age. TBW reduces in the first week of life, resulting in an expected weight loss of up to 10% in a term neonate

Assessment

Examination

• Assess general appearance and hydration status
• Signs of fluid overload – eg periorbital, genital, sacral or peripheral oedema
• Urine output and other fluid losses – check total fluid balance
• Weight – up to 10% loss in a healthy term neonate in week one of life is considered normal

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
• Short gut or other significant gastrointestinal pathology
• Polyuriaespecially in the pre-term neonate (>6 mL/kg/hr is generally considered an indication to assess for polyuria in neonates, discuss with specialist)
• Fluid resuscitation >20 mL/kg required

Management

Resuscitation fluids

For the neonate with signs of shock, refer to resuscitation: care of the seriously unwell neonate

Treat shock with bolus IV fluids to restore circulatory volume:  

Alternative resuscitation fluids such as packed red blood cells or albumin may sometimes be used on senior advice

Maintenance IV fluids

Adjustment of fluid rate is based on day of life calculations alongside daily clinical assessment. All fluid calculations should be performed based on the neonate’s birth weight or highest weight, unless specified otherwise

1. Fluid choice

For neonates >32 weeks and 1500 g

• 10% glucose for the first 24 - 48 hours of life
• After 24 - 48 hours, the addition of sodium and potassium should be considered
• Premade bags are preferable to reduce dose error or infection during mixing or dilution
• Consider Parenteral Nutrition (PN) if it is anticipated that enteral feeding will not be able to be established by Day 5 or with other risk factors such as HIE, necrotising enterocolitis (NEC), or congenital gastrointestinal conditions

* Availability of premade bags can vary and local guidelines may vary. Always follow local injectable guidelines
†0.22% sodium chloride and 0.225% sodium chloride can be used interchangeably

2. Route of administration

Glucose 10% solutions can be administered via peripheral IV cannula

Fluids with glucose concentration above 12.5% or osmolality ≥1000 mOsmol/L  should be administered through a central venous line (either an umbilical catheter or peripherally inserted central catheter) to reduce risk of extravasation/thrombophlebitis

Total fluid requirement
The volume of fluids administered will depend on:

• The gestation of the neonate
• Fluid restriction should be considered in, but not limited to, the following conditions:
• meningitis
• congenital cardiac lesions
• HIE
• renal impairment. Seek senior advice
• Higher fluid requirements may be indicated, but not limited to, the following:
• high insensible losses, such as in extreme prematurity
• neonate receiving phototherapy (see jaundice)
• renal impairment with concentrating defects

Table 1. Fluid requirements (IV) per day of life - Total Fluid Intake (TFI)

Special considerations

• Gastrointestinal tract losses via nasogastric tube or stoma of more than 20 mL/kg/day should be replaced mL for mL with sodium chloride 0.9% + potassium chloride 10 mmol/L over a 24-hour period
• Polyuria in renally impaired or premature neonates may require replacement of urinary losses
• Check the compatibility of IV fluids with any IV drugs that are being co-administered
• Enteral nutritional fluid requirements will be higher

Monitoring

1. Examination – hydration status

• Assess for dehydration
• Signs of fluid overload including oedema (eg periorbital, genital, sacral, peripheral) should also be evaluated, especially in neonates already receiving IV fluid treatment
• Urine output:
  • A term neonate may take up to 24 hours to first pass urine
  • Oliguria is usually defined as <1 mL/kg/hour
  • In preterm neonates <24 hours old: <0.5 mL/kg/hour
• Additional fluid loss eg stomal loss, diarrhoea – check fluid balance, total input versus total output
• Insensible water loss (IWL) can be up to 20 mL/kg/day in a term neonate, and occurs through the skin and mucus membranes (two thirds) and respiratory tract (one third)
• Premature neonates have greater IWL due to immature skin
• Phototherapy may also increase IWL

2. Weight

• All neonates should have a baseline weight at birth or admission, and should be weighed daily if receiving intravenous fluids
• All fluid calculations should be performed based on the neonate’s birth weight or highest weight, unless specified otherwise

Investigations

Serum electrolytes and glucose
See hypoglycaemia

• All neonates requiring fluids for acute conditions should have electrolytes checked prior to commencement of IV fluids (where possible) and again in 24 hours
• Thereafter, these should be checked every 24-48 hours
  • Hypernatraemia usually indicates that the neonate requires more fluid
  • Hyponatraemia may indicate that the neonate requires less fluid, or has high sodium losses
  • Hyponatraemia may also be dilutional, indicating the neonate is receiving excessive fluid volumes or has inadequate urine output
  • Hyperchloraemic metabolic acidosis may occur with higher concentrations or higher volumes of fluids containing sodium chloride

Re-introduction of enteral feeding

Enteral feeding should be considered at the earliest possible opportunity, if safe to do so, under the guidance of a senior clinician

For all neonates
Consider:

• IV fluids should be reduced as enteral intake increases, to achieve a target daily TFI
• IV infusion can usually cease when > 90 mL/kg/day enteral intake achieved
• If at risk for hypoglycaemia, a blood sugar level should be obtained before the second enteral feed (see hypoglycaemia)
• If intravenous access is not required as a route for medications, the cannula should be removed as soon as possible

Term neonates >36 weeks
When introducing enteral feeds for well term neonates:

• Halve IV infusion rate and offer suck feeds (bottle or breast) on demand or at least 4 hourly
• After 2 or 3 adequate suck feeds, IV infusion may be ceased and feeding performance assessed

Pre-term neonates >32 weeks and >1500 g
When introducing enteral feeds for pre-term neonates:

• Consider commencing enteral feeds every 2 - 3 hours
• Start slowly, commencing at 30 mL/kg/day and decrease rate of IV fluids to meet target daily TFI
• Increase enteral intake by 30-40 mL/kg/day.  A slower grade up may be required in certain circumstances, eg in the setting of feed intolerance or worsening respiratory status

Consider consultation with local paediatric or neonatal team when

• Unsure of which/how much fluid to use
• Electrolyte abnormalities
• Significant co-morbidities are present
• Fluid resuscitation >20 mL/kg is required

Consider transfer when

Child requires care above the level of comfort of the local hospital

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

Last updated October 2022