Bicarbonate Therapy in Diabetic Ketoacidosis (DKA)
Bicarbonate therapy in DKA is only indicated in adult patients with severe acidemia (pH < 6.9), while it is not recommended for patients with pH ≥ 7.0 as insulin therapy alone is sufficient to resolve ketoacidosis. 1
Indications for Bicarbonate Therapy
- For adults with pH < 6.9, bicarbonate therapy may be beneficial, though evidence is limited as no prospective randomized studies have been reported for this severe pH range 1
- For adults with pH between 6.9-7.0, bicarbonate therapy has not shown either beneficial or deleterious changes in morbidity or mortality in prospective randomized studies 1
- For pediatric patients, if pH remains < 7.0 after the initial hour of hydration, administration of 1-2 mEq/kg sodium bicarbonate over 1 hour is recommended 1
- Sodium bicarbonate is indicated in severe diabetic acidosis according to FDA labeling, particularly when rapid increase in plasma total CO2 content is crucial 2
Administration Protocol When Indicated
- For adult patients with pH < 6.9, administer 50 mmol sodium bicarbonate diluted in 200 ml sterile water and infused at a rate of 200 ml/h 1
- For pediatric patients with pH < 7.0 after initial hydration, administer 1-2 mEq/kg sodium bicarbonate over 1 hour 1
- When administering bicarbonate, it can be added to NaCl with any required potassium, ensuring the solution does not exceed 155 mEq/L sodium 1
Monitoring During Bicarbonate Therapy
- Monitor serum potassium levels closely as both insulin and bicarbonate therapy lower serum potassium 1
- Check blood glucose every 2-4 hours and measure serum electrolytes, glucose, blood urea nitrogen, creatinine, osmolality, and venous pH every 2-4 hours 1, 3
- Potassium supplementation should be maintained in intravenous fluids and carefully monitored 1
Special Considerations and Cautions
- In patients with DKA and relatively low plasma potassium levels, consider temporarily delaying insulin administration and first administer potassium chloride intravenously to bring plasma potassium level close to 4 mmol/L to prevent cardiac arrhythmias 4
- Bicarbonate therapy should not be administered to children with DKA, except in cases of very severe acidemia with hemodynamic instability refractory to saline administration 4
- The risk of cerebral edema, especially in children, may be increased with bicarbonate therapy, so caution is advised 4
- Recent evidence suggests that even in cases of severe acidemia (pH < 6.6), standard management with IV fluids, insulin, and potassium without bicarbonate therapy can be successful 5
Evidence Quality and Controversies
- The American Diabetes Association guidelines assign a grade C (lower rank) to recommendations regarding bicarbonate therapy, indicating evidence from uncontrolled or poorly controlled studies 1
- Some studies have found no difference in clinical parameters or normalization time of biochemical parameters between patients treated with or without bicarbonate, even in severe DKA (pH between 6.83 and 7.08) 6
- Patients receiving bicarbonate therapy may require significantly more potassium supplementation compared to those not receiving bicarbonate 6
- Current evidence does not support routine use of bicarbonate in DKA with pH values between 6.90 and 7.10 6, 7