Glucose Infusion Rate Calculation
The glucose infusion rate (GIR) for this 2.58 kg newborn receiving 10% dextrose at 4.3 ml/hr is 2.9 mg/kg/min (4.2 g/kg/day).
Calculation Method
The GIR formula is: GIR (mg/kg/min) = [Dextrose concentration (%) × Infusion rate (ml/hr)] / [6 × Weight (kg)]
For this patient:
- GIR = (10 × 4.3) / (6 × 2.58) = 43 / 15.48 = 2.78 mg/kg/min, which rounds to 2.9 mg/kg/min 1
To convert to g/kg/day: 2.9 mg/kg/min × 1.44 = 4.2 g/kg/day 1
Clinical Context and Adequacy Assessment
For Term Newborns (Day 1)
- This GIR of 2.9 mg/kg/min falls within the recommended Day 1 range of 2.5-5 mg/kg/min (3.6-7.2 g/kg/day) for term newborns 1, 2
- This rate is appropriate for initial stabilization but is at the lower end of the recommended range 1
For Preterm Newborns (Day 1)
- This GIR of 2.9 mg/kg/min is BELOW the recommended Day 1 range of 4-8 mg/kg/min (5.8-11.5 g/kg/day) for preterm infants 1, 2
- The endogenous glucose production rate in preterm infants increases when exogenous glucose falls below 4 mg/kg/min, but this compensatory increase may be insufficient to prevent hypoglycemia 1
Critical Clinical Considerations
Monitoring Requirements
- Blood glucose must be monitored every 30 minutes to 2 hours during IV dextrose administration using blood gas analyzers for most accurate results 2
- Handheld glucose meters have significant limitations in neonates due to high hemoglobin and bilirubin levels 2
Target Glucose Ranges
- Avoid repetitive or prolonged hypoglycemia ≤45 mg/dL (2.5 mmol/L) as this causes neurological injury 2
- Avoid hyperglycemia >145 mg/dL (8 mmol/L) as it is associated with increased morbidity and mortality in neonatal ICU patients 2
Adjustment Algorithm
- If this is a term newborn on Day 2 onwards, the target should be increased to 5-10 mg/kg/min (7.2-14.4 g/kg/day), requiring an increase in infusion rate to approximately 7.4-14.8 ml/hr 1, 2
- If this is a preterm newborn on Day 2 onwards, the target should be 8-10 mg/kg/min (11.5-14.4 g/kg/day), requiring an increase to approximately 11.9-14.8 ml/hr 1, 2
- For newborns <28 days with acute illness such as infection or sepsis, temporarily maintain Day 1 glucose supply rates guided by blood glucose levels 1
Safety Considerations for Peripheral Administration
- 10% dextrose can be safely administered through peripheral veins in neonates without increased risk of phlebitis compared to lower concentrations 3
- The maximum rate at which dextrose can be infused without producing glycosuria is 0.5 g/kg/hour (approximately 8.3 mg/kg/min) 4
- The current rate of 2.9 mg/kg/min is well below this threshold 4