From the Guidelines
Sodium bicarbonate (NaHCO3) should not be used as a first-line treatment for metabolic acidosis, except in severe cases with pH < 7.15, where it may be considered with caution (1). The use of sodium bicarbonate in metabolic acidosis is a topic of ongoing debate, with some studies suggesting its effectiveness in certain situations, while others raise concerns about its potential side effects and limited benefits.
- The 2016 Surviving Sepsis Campaign guidelines suggest against the use of sodium bicarbonate therapy to improve hemodynamics or reduce vasopressor requirements in patients with hypoperfusion-induced lactic acidemia with pH ≥ 7.15 (1).
- However, in severe metabolic acidosis, sodium bicarbonate may be considered, particularly when blood pH falls below 7.15 or serum bicarbonate is less than 12 mEq/L (1).
- For acute treatment, sodium bicarbonate can be administered intravenously, typically as an 8.4% solution (1 mEq/mL), with dosing calculated based on the bicarbonate deficit (1).
- Oral sodium bicarbonate tablets (650 mg, equivalent to 7.7 mEq) can be used for less severe cases, typically at doses of 650 mg to 1,300 mg three to four times daily (1).
- It is essential to carefully monitor patients receiving sodium bicarbonate, as side effects can include fluid overload, hypernatremia, and paradoxical cerebrospinal fluid acidosis (1).
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 Treatment of metabolic acidosis should, if possible, be superimposed on measures designed to control the basic cause of the acidosis – e.g., insulin in uncomplicated diabetes, blood volume restoration in shock. But since an appreciable time interval may elapse before all of the ancillary effects are brought about, bicarbonate therapy is indicated to minimize risks inherent to the acidosis itself.
The role of sodium bicarbonate (NaHCO3) in the treatment of metabolic acidosis is to:
- Increase plasma bicarbonate
- Buffer excess hydrogen ion concentration
- Raise blood pH
- Reverse the clinical manifestations of acidosis It is indicated in various forms of metabolic acidosis, including those caused by:
- Severe renal disease
- Uncontrolled diabetes
- Circulatory insufficiency due to shock or severe dehydration
- Cardiac arrest
- Severe primary lactic acidosis Treatment with sodium bicarbonate should be used in conjunction with measures to control the underlying cause of the acidosis 2.
From the Research
Role of Sodium Bicarbonate in Metabolic Acidosis
- Sodium bicarbonate (NaHCO3) has been traditionally used to treat metabolic acidosis, but its effectiveness and safety have been debated 3, 4, 5, 6, 7.
- A study published in 1993 found that low-dose sodium bicarbonate therapy was safe and effective in correcting metabolic acidosis in well-oxygenated patients with mild acidosis 3.
- However, another study published in 1985 highlighted the potential risks of sodium bicarbonate therapy, including hyperosmolar state, high sodium concentration, and increased arterial carbon dioxide tension 4.
- A 2009 review discussed the pros and cons of bicarbonate therapy for patients with severe metabolic acidosis, suggesting that it should be individualized and reserved for patients with an arterial blood pH of ≤7.0 5.
- A retrospective analysis published in 2013 found that sodium bicarbonate administration was associated with higher mortality in patients with lactic acidosis, suggesting that it should be used with caution in this context 6.
- A 2012 review discussed the pathophysiologic approach to treating acute metabolic acidosis, highlighting the importance of assessing acid-base parameters and calculating the serum anion gap to guide therapeutic decisions 7.
Indications and Contraindications
- Sodium bicarbonate may be indicated for patients with severe metabolic acidosis, particularly those with an arterial blood pH of ≤7.0 5.
- However, it should be used with caution in patients with lactic acidosis, as it may exacerbate acidosis and increase mortality 6.
- Alternative buffering agents, such as tris(hydroxymethyl)aminomethane (THAM), may be considered in certain cases, as they may improve acidosis without producing intracellular acidosis 7.
Mechanisms and Effects
- Sodium bicarbonate works by increasing the bicarbonate concentration in the blood, which helps to buffer excess hydrogen ions and correct acidosis 3.
- However, it may also have adverse effects, such as increasing arterial carbon dioxide tension, reducing ionized calcium, and producing hyperosmolality 4, 7.
- The effects of sodium bicarbonate on cellular function and clinical outcomes are complex and require further study 7.