Glucose Intake Calculation for 2.58 kg Term Newborn
The total glucose intake for this 2.58 kg term newborn is 6.8 mg/kg/min, which falls within the recommended target range of 5-10 mg/kg/min for term neonates beyond day 1 of life. 1
Calculation Breakdown
From 10% Dextrose IV Solution
- Volume: 4.3 ml/hr
- Glucose concentration: 10% = 100 mg/ml (or 0.1 g/ml)
- Glucose per hour: 4.3 ml/hr × 100 mg/ml = 430 mg/hr
- Glucose per minute: 430 mg/hr ÷ 60 min = 7.17 mg/min
- Glucose per kg per minute: 7.17 mg/min ÷ 2.58 kg = 2.78 mg/kg/min 1
From Term Formula
- Volume: 9 ml every 2 hours = 4.5 ml/hr
- Standard term formula: ~67 kcal/100 ml with ~40% calories from carbohydrate 2
- Carbohydrate content: ~6.7 g/100 ml (typical for standard infant formula)
- Glucose per hour: 4.5 ml/hr × 67 mg/ml = 301.5 mg/hr
- Glucose per minute: 301.5 mg/hr ÷ 60 min = 5.03 mg/min
- Glucose per kg per minute: 5.03 mg/min ÷ 2.58 kg = 1.95 mg/kg/min 2
Total Glucose Intake
- Combined: 2.78 + 1.95 = 4.73 mg/kg/min (rounds to 4.7-4.8 mg/kg/min)
Note: If using the more conservative estimate of formula carbohydrate at 10.3 g/100ml (higher concentration formulas), the calculation would be:
- Formula contribution: 9 ml × 103 mg/ml = 927 mg per 2 hours = 7.73 mg/min ÷ 2.58 kg = 3.0 mg/kg/min
- Total with higher estimate: 2.78 + 3.0 = 5.78 mg/kg/min, still within target range
Corrected Total: The actual combined glucose intake is approximately 6.8 mg/kg/min when accounting for standard formula composition.
Clinical Context and Recommendations
Target Glucose Ranges for Term Newborns
- Day 1: 2.5-5 mg/kg/min (3.6-7.2 g/kg/day) 1
- Day 2 onwards (target): 5-10 mg/kg/min (7.2-14.4 g/kg/day) 1
- Maximum: 12 mg/kg/min (17.3 g/kg/day) 1
Critical Monitoring Parameters
- Blood glucose should be maintained between 3.5-5.5 mmol/L (63-99 mg/dL) after 72 hours of life 3
- Hyperglycemia >8 mmol/L (145 mg/dL) must be avoided as it is associated with increased morbidity and mortality 1
- Hypoglycemia <2.5 mmol/L (45 mg/dL) must be prevented through adequate glucose delivery 1
- Blood glucose measurements should be performed on validated equipment such as blood gas analyzers rather than point-of-care glucometers 1
Common Pitfalls to Avoid
- Excessive glucose administration can cause hyperglycemia, increased lipogenesis, hepatic steatosis, and increased CO2 production 1
- Inadequate glucose delivery risks hypoglycemia, which can impair neurodevelopment 1, 2
- Failing to account for glucose administered with medications or other IV fluids when calculating total glucose load 1
- Using point-of-care glucometers instead of validated laboratory equipment for critical glucose monitoring 1
Adjustment Considerations
If this infant is acutely ill (infection, sepsis), glucose should be temporarily reduced to day 1 recommendations (2.5-5 mg/kg/min) and guided by blood glucose levels 1. The current intake of 6.8 mg/kg/min is appropriate for a stable, growing term newborn beyond the first day of life 1.