NICU Glucose Infusion Rate Calculator
Calculate GIR (mg/kg/min) and Total Fluid Intake for Neonates
What is Glucose Infusion Rate (GIR)?
The Glucose Infusion Rate (GIR) is a critical calculation in the Neonatal Intensive Care Unit (NICU). It measures the amount of glucose a neonate is receiving per minute, normalized by their body weight. Maintaining an appropriate GIR is vital for preventing hypoglycemia (low blood sugar) or hyperglycemia (high blood sugar), both of which can have severe neurological and physiological consequences for premature and sick infants.
The GIR Formula
The standard formula used to calculate the Glucose Infusion Rate is:
Where:
- Rate: The speed at which the IV fluid is running (mL/hr).
- Dextrose Concentration: The percentage of dextrose in the IV fluid (e.g., D10W is 10%).
- 0.1667: A conversion factor derived from (1000 mg/g) / (60 min/hr) / 100 (for percentage). Simplified, this is often expressed as dividing by 6.
Normal Ranges and Clinical Goals
While specific targets vary based on the infant's gestational age and clinical condition, general guidelines for initial GIR are:
- Term Infants: 3 – 5 mg/kg/min
- Preterm Infants: 4 – 8 mg/kg/min
- Maximum Tolerance: Usually up to 12 – 14 mg/kg/min, though insulin may be required at higher rates.
Total Fluid Intake (TFI)
In addition to GIR, this calculator provides the Total Fluid Intake (TFI) in mL/kg/day. Monitoring TFI is essential to manage hydration status, renal function, and electrolyte balance. A typical starting TFI for a neonate might range from 60 to 80 mL/kg/day, increasing gradually over the first week of life to 120–150 mL/kg/day depending on protocol and patient needs.