Sodium Bicarbonate Infusion for Acidosis
For patients with metabolic acidosis, sodium bicarbonate infusion should be administered at 1-2 mEq/kg given slowly via IV/IO route, followed by an infusion of 150 mEq NaHCO3/L solution in specific clinical scenarios, but is not recommended for routine use in all acidotic states. 1, 2
Indications for Sodium Bicarbonate Therapy
Sodium bicarbonate infusion is indicated in the following specific conditions:
- Documented metabolic acidosis - Only after effective ventilation has been established, as ventilation is needed to eliminate excess CO2 produced by bicarbonate 1
- Hyperkalemia - Bicarbonate therapy can help shift potassium into cells 1
- Sodium channel blocker overdose (e.g., tricyclic antidepressant toxicity) - Titrate to maintain serum pH of 7.45-7.55 1
- Severe metabolic acidosis with acute kidney injury - Recent evidence shows improved survival in this specific subgroup 3
Contraindications and Cautions
- Routine use in cardiac arrest is not recommended 1
- Respiratory acidosis - Bicarbonate may worsen intracellular acidosis due to CO2 generation 4, 5
- Hypocalcemia - Bicarbonate therapy can worsen ionized hypocalcemia 2, 5
- Do not mix sodium bicarbonate with vasoactive amines or calcium 1
Dosing Protocol
Initial Bolus Dosing:
- Standard dose: 1-2 mEq/kg IV/IO given slowly 1, 2
- For cardiac arrest or severe acidosis: 1-2 vials (44.6-100 mEq) may be given initially 2
Maintenance Infusion:
- For sodium channel blocker overdose: After initial bolus, continue with infusion of 150 mEq NaHCO3/L solution to maintain alkalosis 1
- For less urgent metabolic acidosis: 2-5 mEq/kg over 4-8 hours, depending on severity 2
Monitoring:
- Guide therapy by bicarbonate concentration or calculated base deficit from blood gas analysis 1, 2
- Monitor serum electrolytes, especially sodium, potassium, and ionized calcium 4, 5
- Follow arterial pH and blood gases to avoid overcorrection 2, 5
Special Considerations
- Only use 0.5 mEq/mL concentration for newborn infants; dilution of available stock solutions may be necessary 1
- Do not attempt complete correction of base deficit in the first 24 hours to avoid iatrogenic alkalosis 2
- Target total CO2 content of about 20 mEq/L at the end of the first day of therapy 2
- Consider THAM (tromethamine) as an alternative alkalizing agent in patients with hypernatremia or high PaCO2 levels 4
Potential Adverse Effects
- Extracellular alkalosis shifting the oxyhemoglobin curve and inhibiting oxygen release 1
- Hypernatremia and hyperosmolarity 1, 2, 5
- Excess CO2 production leading to paradoxical intracellular acidosis 1, 5
- Hypokalemia 4, 5
- Hypocalcemia 3, 5
- Inactivation of simultaneously administered catecholamines 1
Recent Evidence
Recent research suggests that in patients with severe metabolic acidemia and acute kidney injury, sodium bicarbonate therapy may decrease mortality at 28 days 3. However, in patients without kidney injury or with mild acidosis, routine use does not improve outcomes and may cause harm 6, 7.
For sepsis-related acidosis, current evidence does not support routine bicarbonate use, particularly when arterial pH is >7.15 1, 7.