Dose of 1 Ampule of Sodium Bicarbonate
One ampule of sodium bicarbonate contains 50 mL of 8.4% solution, which equals 50 mEq (1 mEq/mL) of sodium bicarbonate. 1
Composition and Formulations
Sodium bicarbonate is available in different concentrations, with the standard ampule being:
- 8.4% solution (84 mg/mL)
- 1 mEq/mL of sodium and bicarbonate
- 50 mL ampule = 50 mEq total
- Osmolarity: 2 mOsmol/mL
Other available concentrations include:
- 7.5% (0.9 mEq/mL) - 44.6 mEq in 50 mL
- 4.2% (0.5 mEq/mL) - 5 mEq in 10 mL
Clinical Applications and Dosing
Cardiac Arrest
- Initial dose: 1-2 ampules (50-100 mEq) IV rapid push
- May continue at 50 mEq every 5-10 minutes if necessary based on arterial pH and blood gas monitoring 1
- Use caution with rapid infusion of large quantities as bicarbonate solutions are hypertonic
Severe Metabolic Acidosis (pH < 7.0)
- Initial dose: 1-2 mEq/kg IV bolus (1-2 mL/kg of 8.4% solution) 2, 3
- Follow with 2-5 mEq/kg over 4-8 hours depending on severity 3
- Monitor arterial blood gases to guide therapy
Sodium Channel Blocker/TCA Overdose
- Initial dose: 1-2 mEq/kg (1-2 mL/kg of 8.4% solution) 2
- Can be repeated as needed for clinical stability
- Maximum recommended dose: 6 mEq/kg to avoid hypernatremia, fluid overload, and metabolic alkalosis 4
Less Urgent Metabolic Acidosis
- 2-5 mEq/kg over 4-8 hours depending on severity 1
- Target partial correction initially (aim for bicarbonate ~20 mEq/L in first 24 hours) 1
- Complete correction may lead to paradoxical alkalosis
Important Considerations
Monitoring
- Regular monitoring of arterial blood gases, serum electrolytes (especially potassium, sodium, calcium), ECG, blood pressure, and mental status is essential 3
- Stepwise therapy is recommended as response to a given dose is not precisely predictable 1
Adverse Effects
- Hypernatremia
- Hyperosmolarity
- Extracellular alkalosis
- Paradoxical intracellular acidosis
- Excess CO₂ production
- Hypocalcemia
- Hypokalemia
- Fluid overload
Special Populations
- In mechanically ventilated patients: Increase minute ventilation to compensate for additional CO₂ production 3
- In renal failure: Consider lower doses and slower administration 3
- For newborns: Use only 0.5 mEq/mL concentration (4.2% solution) 3
Clinical Pitfalls to Avoid
- Avoid full correction of metabolic acidosis within the first 24 hours, as this may lead to unrecognized alkalosis 1
- Do not administer for mild metabolic acidosis (pH ≥ 7.15) as risks may outweigh benefits 3
- For sodium channel blocker poisonings, do not continue dosing solely based on QRS duration, as some drugs don't respond and QRS normalization takes time 4
- Avoid simultaneous administration with catecholamines as bicarbonate may inactivate them 3
- In patients with mixed respiratory and metabolic acidosis, use caution as bicarbonate therapy can worsen respiratory acidosis by increasing CO₂ production 5