What is the role of sodium bicarbonate (NaHCO3) administration in the treatment of lactic acidosis?

From the Guidelines

Sodium bicarbonate administration is not recommended for the treatment of lactic acidosis with a pH ≥ 7.15, as it has not been shown to improve hemodynamics or reduce vasopressor requirements. The use of sodium bicarbonate in this context is based on weak recommendation and moderate quality of evidence, as stated in the 2016 Surviving Sepsis Campaign guidelines 1.

Key Considerations

• The guidelines suggest against the use of sodium bicarbonate therapy to improve hemodynamics or to reduce vasopressor requirements in patients with hypoperfusion-induced lactic acidemia with pH ≥ 7.15 1.
• Two blinded, crossover RCTs compared equimolar saline and sodium bicarbonate in patients with lactic acidosis and failed to reveal any difference in hemodynamic variables or vasopressor requirements 1.
• Bicarbonate administration has been associated with potential adverse effects, including sodium and fluid overload, an increase in lactate and Paco2, and a decrease in serum ionized calcium 1.

Treatment Approach

• The primary approach to lactic acidosis should focus on treating the underlying cause, such as improving tissue perfusion, managing sepsis, or discontinuing offending medications.
• Sodium bicarbonate administration can have adverse effects, including paradoxical intracellular acidosis, volume overload, hypernatremia, hyperosmolality, and decreased ionized calcium.
• Treatment decisions should be individualized based on the clinical context, severity of acidosis, and underlying etiology.

Specific Situations

• Sodium bicarbonate may be considered in severe cases with pH < 7.1 or in specific situations like certain drug toxicities or renal tubular acidosis, but this is not supported by the provided evidence 1.
• When used, careful monitoring of pH and electrolytes is necessary, and the dosing should be tailored to the individual patient's needs.

From the FDA Drug Label

Sodium Bicarbonate Injection, USP is indicated in the treatment of metabolic acidosis which may occur in severe renal disease, uncontrolled diabetes, circulatory insufficiency due to shock or severe dehydration, extracorporeal circulation of blood, cardiac arrest and severe primary lactic acidosis Vigorous bicarbonate therapy is required in any form of metabolic acidosis where a rapid increase in plasma total CO2 content is crucial - e. g., cardiac arrest, circulatory insufficiency due to shock or severe dehydration, and in severe primary lactic acidosis or severe diabetic acidosis.

Sodium bicarbonate administration is indicated for the treatment of severe primary lactic acidosis as a form of metabolic acidosis. The treatment should be used to minimize risks inherent to the acidosis itself, and vigorous bicarbonate therapy is required in severe cases 2.

• Key points:
  • Indicated for severe primary lactic acidosis
  • Used to minimize risks inherent to the acidosis
  • Vigorous bicarbonate therapy is required in severe cases
  • Treatment should be superimposed on measures designed to control the basic cause of the acidosis.

From the Research

Sodium Bicarbonate Administration for Lactic Acidosis

• The use of sodium bicarbonate for the treatment of lactic acidosis is a controversial topic, with some studies suggesting that it may not be effective in improving patient outcomes 3, 4, 5, 6.
• The administration of sodium bicarbonate may even have negative side effects, such as decreasing vasomotor tone, decreasing myocardial contractility, and inducing intracellular acidosis 4, 5, 6.
• Some studies suggest that sodium bicarbonate may only be beneficial in patients with severe acidemia (pH < 7.2) and acute kidney injury 5.
• The most effective therapy for lactic acidosis is to reverse the underlying cause, rather than relying on sodium bicarbonate administration 3, 4, 6.
• Alternative treatments, such as peritoneal dialysis and hemodialysis, may be more effective in delivering physiologic buffer and correcting acidemia 7.
• Other potential treatments, such as dichloroacetate and insulin therapy, may also be useful in certain cases of lactic acidosis 7.

Key Findings

• Sodium bicarbonate administration is not recommended for patients with lactic acidosis and a pH ≥ 7.2 3, 6.
• The use of sodium bicarbonate in patients with severe acidemia (pH < 7.2) should be approached with caution and considered on a case-by-case basis 5, 6.
• Alternative treatments, such as peritoneal dialysis and hemodialysis, may be more effective in delivering physiologic buffer and correcting acidemia 7.

Considerations for Administration

• If sodium bicarbonate is administered, it should be given as a slow IV infusion in the setting of adequate ventilation and calcium replacement to mitigate its untoward effects 5, 6.
• The potential benefits and risks of sodium bicarbonate administration should be carefully considered, and alternative treatments should be explored 3, 4, 5, 6, 7.