Fluids - Fluid and Glucose requirements
Fluid volumes administered in NICU after the first week are high to ensure good caloric intake and growth in preterm infants. Term infants have a lower requirement for fluids and calories.
Recommended Volumes (ml/kg/day)
| Day 0-1 | Day 2 | Day 3 | Day 4 | Day 5 | Day 6 | Day 7+ | |
| <37 weeks | 60 | 75 | 90 | 105 | 120 | 150 | 180 |
| 37 weeks+ | 60 | 75 | 90 | 105 | 120 | 120 | 150 |
Fluid volumes administered in NICU after the first week are high to ensure good energy intake and growth in preterm infants. Term infants have a lower requirement for fluids and calories.
Infants admitted to Starship Hospital (surgical or medical services) should have fluids prescribed according to Starship Hospital guidelines (available via the intranet).
The volume administered will depend on the clinical condition of the infant, with fluid restriction indicated with asphyxia, renal impairment or PDA.
Infants receiving phototherapy, or with high insensible losses, may require higher fluid intakes.
In general, fluid management in the first few days is adjusted primarily on serum sodium values and changes in weight.
High serum sodium values usually indicate that the infant requires more fluid.
Low serum sodium values may indicate that the infant requires less fluid, or that the infant has high sodium losses.
There is evidence that restricting fluid volumes in preterm infants in the first few days of life reduces the incidence of patent ductus arteriosus and necrotising enterocolitis, and may decrease mortality rates.¹
Restricting sodium intake in preterm infants in the first few days may also reduce the incidence of chronic lung disease.²,³,⁴,⁵
Glucose intake
The neonatal liver normally produces 6-8 mg/kg/min of glucose. This is approximately the basal requirement of a newborn infant.
Hypoglycaemia is severe if it persists despite an intake of >10 mg/kg/min. Calculate the glucose intake: See also the Glucose Calculator
Glucose intake (mg/kg/min) = % Glucose x Volume (ml/kg/day)
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or
Glucose intake (mg/kg/min) = % Glucose x Hourly Rate
Weight (Kg) x 6
| Intake (ml/kg/day) | 5% Glucose | 10% Glucose | 12.5% Glucose |
| mg/kg/min of Glucose | |||
| 60 | 2.1 | 4.2 | 5.2 |
| 75 | 2.6 | 5.2 | 6.5 |
| 90 | 3.1 | 6.3 | 7.8 |
| 105 | 3.7 | 7.3 | 9.1 |
| 120 | 4.2 | 8.3 | 10.4 |
| 150 | 5.2 | 10.4 | 13.0 |
| 180 | 6.3 | 12.5 | 15.6 |
To get concentrated glucose solutions: See the Fluid and Electrolytes calculator
Glucose solutions of >10% are best administered through central venous lines. Peripheral IVs do not last long, and extravasation can result in tissue damage.
Insensible Water Loss
This varies greatly with gestation and depends on the thermal environment. It decreases markedly over the first few days. Very preterm infants should be placed in humidified incubators in a neutral thermal environment as soon as practical after birth.
Gastrointestinal Losses
If there are significant gastric aspirates, replace these ml for ml with 0.9% NaCl plus 10mmol KCl per 500ml.
Chest and/or Peritoneal Drains
If there are significant fluid losses from these, measure the volume and replace with 4% albumin as indicated.
Monitor serum albumin concentrations.
Monitor the composition of the fluid being lost as this may assist with calculating requirements
Renal Impairment
Restrict intake to insensible water loss + urine output.
Monitor fluid balance, serum electrolytes and weight carefully.
In early Acute Tubular Necrosis, consider a pre-renal cause. Fractional excretion of sodium may help sort this out.
FE Na⁺ ≥2.5% in term infants suggests renal failure.
FE Na⁺ <2.5% in term infants suggests pre-renal failure.
FE Na⁺ is high in preterm infants because of tubular immaturity.
FE Na⁺= Urine [Na] x Serum Creatinine
Serum [Na+] x Urine Creatinine x 100%