GIR Calculator (Glucose Infusion Rate)
The Glucose Infusion Rate (GIR) tells you how much glucose a patient is receiving per kilogram per minute from an IV dextrose infusion. It is a key metric in neonatal care, pediatric endocrinology, and critical care for managing blood glucose levels.
GIR is calculated using the formula: GIR (mg/kg/min) = (Dextrose Concentration % x Infusion Rate in mL/hr) / (Patient Weight in kg x 6). The factor of 6 accounts for the unit conversions between percentage, milliliters, hours, and minutes.
In neonates, the target GIR is typically 4 to 8 mg/kg/min. Newborns who need more than 12 mg/kg/min to maintain normal blood glucose may have congenital hyperinsulinism or other metabolic conditions requiring further workup. For adults, the physiologic glucose production rate is about 2 to 3 mg/kg/min, and IV dextrose targets are usually 2 to 5 mg/kg/min.
Common clinical scenarios for GIR calculations:
- Neonatal hypoglycemia: Initial treatment often starts with D10W at a rate that provides 5-8 mg/kg/min
- TPN (total parenteral nutrition): GIR helps ensure the dextrose component does not exceed the body's oxidation capacity (typically 4-7 mg/kg/min in adults)
- Insulin drip management: GIR is used alongside insulin infusion protocols, especially in DKA
Dextrose provides 3.4 kcal per gram (compared to 4.0 kcal/g for dietary carbohydrate) because IV dextrose is the monohydrate form. This calculator includes the caloric contribution for nutrition planning.
This tool is for educational and reference purposes. All IV medication calculations should be independently verified before clinical use.