How to Calculate GIR

Glucose (sugar) is a major source of energy in the body, and when it is at low levels in the blood, the condition is called hypoglycemia. The usual treatment of hypoglycemia is intravenous (IV) administration of a glucose solution. GIR stands for the glucose infusion rate that is measured in mg/kg/minute, indicating the amount of glucose delivered per minute per kilogram of body mass.

Things You'll Need

• Calculator

Instructions

1. Obtain a patient weight (in kilograms) from records or elsewhere. If the weight is given in pounds, multiply it by 0.4536 to get kilograms. For example, if the body mass is 95 pounds:
   Weight = Weight (lb.) * 0.4536 = 95 lb. * 0.4536 = 43.09 kg

2. Divide the IV rate (in mL/hour) by 60 to convert it to mL/minute units. For example, for the IV rate of 12 mL/hour:
   12 / 60 = 0.2 mL/minute

3. Multiply by 10 the glucose concentration in an IV line given as "g per deciliter (dL)" to convert it to mg/mL. For example, the concentration of 15 g/dL converts to 150 mg/mL.

4. Multiply the IV rate (Step 2) and glucose concentration (Step 3) and then divide the product by the weight (Step 1) to calculate GIR:
   GIR (mg/kg/minute) = IV rate (mL/minute) * Glucose concentration (mg/mL) / Weight (kg)

   In our example:
   GIR = 0.2 * 150 / 43.09 = 0.7 mg/kg/minute

Resources

• Vanderbilt University Medical Center: Glucose Infusion Rate