What is the appropriate dose of sodium bicarbonate (HCO3) for a patient with metabolic acidosis?

From the Guidelines

For patients with metabolic acidosis, the appropriate dose of sodium bicarbonate (HCO3) is usually about 2 to 4 g/d or 25 to 50 mEq/d, administered orally to effectively increase serum bicarbonate concentrations 1. The goal of sodium bicarbonate therapy is to maintain serum bicarbonate at or above 22 mmol/L, which can help reduce protein degradation and increase albumin synthesis.

• Key considerations for sodium bicarbonate therapy include:
  • Monitoring serum bicarbonate levels regularly, at monthly intervals, to assess the need for correction of metabolic acidemia
  • Using higher concentrations of bicarbonate in hemodialysate (38 mmol/L) to safely increase predialysis serum bicarbonate concentrations
  • Administering oral sodium bicarbonate to increase serum bicarbonate concentrations, with a typical dose of 2 to 4 g/d or 25 to 50 mEq/d
  • Considering the potential benefits of correcting acidemia, including increased serum albumin, decreased protein degradation rates, and increased plasma concentrations of branched chain amino acids and total essential amino acids 1. In terms of specific dosing, the recommended oral dose of sodium bicarbonate is typically in the range of 25 to 50 mEq/d, which can be adjusted based on individual patient needs and response to therapy 1.
• It is essential to note that sodium bicarbonate therapy should be tailored to the individual patient's needs, taking into account the severity and cause of the metabolic acidosis, as well as any underlying medical conditions or concomitant therapies. The use of sodium bicarbonate therapy has been associated with several benefits, including increased serum albumin, decreased protein degradation rates, and increased plasma concentrations of branched chain amino acids and total essential amino acids 1.
• Overall, the key to effective sodium bicarbonate therapy is to monitor serum bicarbonate levels closely and adjust the dose as needed to maintain serum bicarbonate at or above 22 mmol/L, while also being mindful of potential side effects and interactions with other therapies 1.

From the FDA Drug Label

In cardiac arrest, a rapid intravenous dose of one to two 50 mL syringes (44.6 to 100 mEq) may be given initially and continued at a rate of 50 mL (44. 6 to 50 mEq) every 5 to 10 minutes if necessary In less urgent forms of metabolic acidosis, ... approximately 2 to 5 mEq/kg of body weight – depending upon the severity of the acidosis

The appropriate dose of sodium bicarbonate (HCO3) for a patient with metabolic acidosis is:

• Initial dose: 1 to 2 syringes of 50 mL (44.6 to 100 mEq) in cardiac arrest
• Subsequent dose: 50 mL (44.6 to 50 mEq) every 5 to 10 minutes if necessary
• Less urgent forms: 2 to 5 mEq/kg of body weight over 4 to 8 hours, depending on severity of acidosis 2

From the Research

HCO3 Dose

• The appropriate dose of sodium bicarbonate (HCO3) for a patient with metabolic acidosis is not explicitly stated as 100 ml, but rather should be calculated to bring the pH up to 7.2, as suggested by 3.
• A simple formula for bedside calculation of bicarbonate requirement in metabolic acidosis has been devised, which aims to elevate the pH to around 7.30, as reported by 4.
• The use of sodium bicarbonate in patients with metabolic acidosis should be individualized, and the amount given should be what is calculated to bring the pH up to 7.2, as stated by 3.
• In one study, 85 ml of 8.4% sodium bicarbonate was used to treat rises in intracranial pressure, and was found to be effective, as reported by 5.
• However, it is also important to note that sodium bicarbonate can have adverse haemodynamic effects, and its use should be monitored closely, as warned by 6.

Administration Considerations

• Sodium bicarbonate should be given at an arterial blood pH of < or =7.0, as suggested by 3.
• The use of sodium bicarbonate in patients with mild metabolic acidosis has been compared to the use of THAM, and was found to have a similar alkalinizing effect, but with a longer lasting effect, as reported by 7.
• Sodium bicarbonate can decrease serum potassium levels, and increase serum sodium levels, as noted by 7.
• THAM, on the other hand, does not decrease serum potassium levels, and may be preferred in patients with hyperkalemia or hypernatremia, as suggested by 7.