GIR (Glucose Infusion Rate)

Why use it

Prevents neonatal hypoglycemia and hyperglycemia. Guides TPN dextrose titration. Essential for NICU glucose management. Monitors glucose delivery in critically ill patients.

About

Calculates the Glucose Infusion Rate (GIR) in mg/kg/min from the concentration of dextrose solution and the infusion rate. GIR is essential for neonatal glucose management, TPN administration, and preventing hypoglycemia or hyperglycemia in critically ill patients.

When to use

• Neonatal IV glucose management
• TPN initiation and adjustment
• Insulin infusion management in ICU
• Calculating glucose delivery from maintenance fluids

Formula

Pearls & pitfalls

• D10W at maintenance rate provides ~5-6 mg/kg/min in neonates — a typical starting GIR.
• D5W provides roughly half the GIR of D10W at the same rate.
• Max GIR for neonates: ~12 mg/kg/min. Exceeding this risks hyperglycemia and hepatic steatosis.
• Adults on TPN: keep GIR < 4-5 mg/kg/min to avoid hyperglycemia.
• Dextrose concentrations: D5 = 5 g/100mL = 50 mg/mL, D10 = 100 mg/mL, D50 = 500 mg/mL.
• If GIR is adequate but hypoglycemia persists, consider hyperinsulinism, adrenal insufficiency, or metabolic disease.

Next steps

Target GIR: Neonates 4-6 mg/kg/min (start), up to 12 mg/kg/min max. Adults on TPN: typically 3-5 mg/kg/min. GIR > 10-12 may cause hepatic steatosis. Monitor blood glucose every 1-6 hours during adjustments.

Evidence

Standard neonatal and critical care practice. AAP neonatal glucose management guidelines recommend maintaining adequate GIR to prevent hypoglycemia (blood glucose > 45 mg/dL in neonates).

References

1. Adamkin DH. Neonatal hypoglycemia. Semin Fetal Neonatal Med. 2017;22(1):36-43. — link