What are the indications for bicarbonate (sodium bicarbonate) use in diabetic ketoacidosis (DKA)?

From the Guidelines

Sodium bicarbonate is generally not recommended for routine use in diabetic ketoacidosis (DKA), and its use should be limited to specific severe circumstances, such as when arterial pH is less than 6.9, in cases of life-threatening hyperkalemia, or when cardiac function is compromised due to severe acidosis, as stated in the most recent guidelines 1. The indications for bicarbonate use in DKA are limited due to several concerns, including the potential to worsen hypokalemia, cause paradoxical central nervous system acidosis, delay ketone clearance, and provide no additional benefit since metabolic acidosis typically resolves with proper insulin therapy and fluid resuscitation. Key points to consider in the management of DKA include:

• Restoration of circulatory volume and tissue perfusion
• Resolution of hyperglycemia
• Correction of electrolyte imbalance and acidosis
• Treatment of any correctable underlying cause of DKA, such as sepsis, myocardial infarction, or stroke
• Use of continuous intravenous insulin in critically ill and mentally obtunded patients
• Successful transition from intravenous to subcutaneous insulin requires administration of basal insulin 2–4 h before the intravenous insulin is stopped to prevent recurrence of ketoacidosis and rebound hyperglycemia, as recommended in recent guidelines 1. If bicarbonate is deemed necessary, it can be administered as an isotonic solution (150 mEq sodium bicarbonate in 1 L of sterile water) infused at 1-2 mEq/kg over 60 minutes, with reassessment of pH and potassium levels afterward, although this is not explicitly stated in the most recent guidelines, previous recommendations suggest this approach 1. Most DKA patients recover successfully with the standard treatment approach of insulin administration, aggressive fluid replacement, and electrolyte management, making bicarbonate unnecessary in the majority of cases, and clinicians should focus on addressing the underlying causes of DKA rather than treating the acidosis directly with bicarbonate, as emphasized in the latest standards of care in diabetes 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 Vigorous bicarbonate therapy is required in any form of metabolic acidosis where a rapid increase in plasma total C02 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.

The indications for bicarbonate (sodium bicarbonate) use in diabetic ketoacidosis (DKA) are:

• Severe diabetic acidosis
• Metabolic acidosis which may occur in uncontrolled diabetes Key points to consider:
• Bicarbonate therapy is indicated to minimize risks inherent to the acidosis itself
• Treatment of metabolic acidosis should be superimposed on measures designed to control the basic cause of the acidosis, such as insulin in uncomplicated diabetes 2

From the Research

Indications for Bicarbonate in DKA

The use of sodium bicarbonate in diabetic ketoacidosis (DKA) is a topic of controversy, with various studies providing insights into its indications. The following points summarize the indications for bicarbonate use in DKA:

• According to the American Diabetes Association, intravenous bicarbonate may be considered for patients with a pH less than 6.9 3.
• A study published in 2024 suggests that IV sodium bicarbonate can be considered if the serum pH falls below 6.9, or when serum pH is less than 7.2 and/or serum bicarbonate levels are below 10 mEq/L, pre- and post-intubation, to prevent metabolic acidosis and hemodynamic collapse that occurs from apnea during intubation 4.
• Another study published in 2018 notes that there is scant data to support or refute the role of bicarbonate therapy in very severe acidosis, and that arterial blood gas (ABG) assessment is an element of some treatment protocols, including society guidelines, for DKA 5.
• A 2023 review of DKA management highlights the controversies regarding certain aspects of treatment, including optimal fluid resuscitation, rate and type of insulin therapy, potassium and bicarbonate replacement, but does not provide specific indications for bicarbonate use 6.
• A 2020 primer on DKA discusses the epidemiology, pathogenesis, risk factors, and diagnosis of DKA, but does not provide specific indications for bicarbonate use 7.

Special Considerations

In addition to the above indications, the following special considerations may influence the use of bicarbonate in DKA:

• Patients with severe DKA and pH less than 7.0 may require serial ABG monitoring and/or sodium bicarbonate infusion 5.
• Patients with impending respiratory failure may require intubation and mechanical ventilation, with monitoring and management of acid-base and fluid status, and IV sodium bicarbonate may be considered to prevent metabolic acidosis and hemodynamic collapse 4.
• Patients with specific conditions and comorbidities, such as pregnancy, renal disease, congestive heart failure, acute coronary syndrome, older age, and use of sodium-glucose cotransporter-2 (SGLT2) inhibitors, may require tailored management strategies, including the use of bicarbonate 6.