Bicarbonate Deficit

Calculates bicarbonate deficit in metabolic acidosis to guide bicarbonate replacement therapy.

kg
Patient weight in kg.
mEq/L
Measured serum bicarbonate.
mEq/L
Desired bicarbonate level. Usually 15-18 in acute, or 20-22.

Enter weight and bicarbonate values to calculate deficit

References

  1. Bicarbonate Deficit Calculator — MDCalc (2025)

Clinical Notes & Warnings

  • Bicarbonate replacement is controversial and not routinely recommended for all metabolic acidosis.
  • Indications for bicarbonate: pH <7.1, HCO3 <5, hemodynamic instability, hyperkalemia with ECG changes.
  • Risks of bicarbonate: volume overload, hypernatremia, hypokalemia, rebound alkalosis, left shift of oxyhemoglobin curve.
  • In DKA, bicarbonate NOT recommended unless pH <6.9.
  • Consider treating underlying cause (e.g., DKA resuscitation, lactic acidosis resuscitation) rather than just giving bicarbonate.

The volume of distribution for bicarbonate varies (0.4-0.6 L/kg). The 0.5 factor is commonly used. Replace only half the calculated deficit to avoid overshoot alkalosis. 1 ampule of NaHCO3 = 50 mEq in 50 mL.