Weight
kg
Dextrose
Single concentration
#1
Dextrose concentration
IV rate
mL/hr
Results
GIR
mg/kg/min

GIR calculator (Glucose Infusion Rate)

By Joanna Michałowska, PhD candidate

The GIR calculator allows you to calculate the total glucose infusion rate from a mix of up to three concentrations of dextrose. In the article below, you will find the relevant glucose infusion rate formula, and some supplementary information.

You can also check out our other pediatric calculators, including the APGAR score calculator, weight percentile calculator and height percentile calculator.

Glucose infusion rate

Dextrose is a simple sugar that is chemically identical to glucose. It can be found in many food products, but can be used for medical purposes as well. When administrated intravenously, dextrose increases a patient's blood sugar.

The glucose infusion rate (GIR) is a measure of how quickly the patient receives these carbohydrates. Calculating GIR is a standard procedure for all infants receiving parenteral dextrose, and allows the practitioner to ensure that the neonate's blood glucose level is at an acceptable level. We express GIR in terms of milligrams of glucose per kilogram body weight per minute (mg/kg/min).

Below you can see the recommendations for GIR:

  • An initial range of 4 to 6 mg/kg/min should be assigned for term infants;
  • An initial range of 5 to 8 mg/kg/min should be assigned for preterm infants;
  • A GIR < 4 mg/kg/min can induce a catabolic state and cause neurological injury; and
  • A GIR >18–20 mg/kg/min increases the risk of lipogenesis, and fatty deposits in the liver.

Glucose infusion rate formula

The glucose infusion rate formula below shows how to calculate GIR from dextrose concentration:

GIR = [IV rate (mL/hr) * Dext Conc (g/dL) * 1000 (mg/g)] / [weight (kg) * 60 (min/hr) * 100 (mL/dL)]

where:

GIR - the glucose infusion rate;

IV rate - the infusion rate;

Dext Conc - the dextrose concentration; and

weight - the patient's weight.

GIR calculator

The GIR calculator allows you to calculate total glucose infusion rate from a mix of up to three concentrations of dextrose. Just follow these three steps:

  1. First of all, input patient's weight.
  2. Choose if you have one concentration of dextrose, or if you want mix a few different ones.
  3. Enter the dextrose concentration(s) and infusion rate(s) to calculate GIR from dextrose concentration.

Calculate GIR from dextrose concentration - an example

An infant weighs 2 kg and is receiving two concentrations of dextrose:

  • A 5% solution of dextrose with the IV rate of 15 ml/hr; and
  • A 10% solution of dextrose with the IV rate of 10 ml/hr.
  1. We need to calculate GIR for the 5% solution of dextrose:

GIR = [IV rate (mL/hr) * Dext Conc (g/dL) * 1000 (mg/g)] / [weight (kg) * 60 (min/hr) * 100 (mL/dL)]

GIR = [15 mL/hr * 5 g/dL * 1000 mg/g] / [2 kg * 60 min/hr * 100 mL/dL]

GIR = 75,000 / 12,000

GIR = 6.25 mg/kg/min

  1. In the next step, we will calculate GIR for the 10% solution of dextrose:

GIR = [10 mL/hr * 10 g/dL * 1000 mg/g] / [2 kg * 60 min/hr * 100 mL/dL]

GIR = 100,000 / 12,000

GIR = 8.33 mg/kg/min

  1. Now the final glucose infusion rate can be calculated:

GIR = GIR1 + GIR2

GIR = 6.25 mg/kg/min + 8.33 mg/kg/min

GIR = 14.6 mg/kg/min

We try our best to make our Omni Calculators as precise and reliable as possible. However, this tool can never replace professional medical advice.

Joanna Michałowska, PhD candidate