Sodium Bicarbonate 8.4% Solution: Concentration Clarification
No, an 8.4% sodium bicarbonate solution does not contain 150 mEq per se—it contains 1000 mEq/L (or 1 mEq/mL), which means you would need 150 mL of 8.4% solution to deliver 150 mEq of sodium bicarbonate. 1, 2
Understanding the Concentration
8.4% sodium bicarbonate is a hypertonic solution with a concentration of 1 mEq/mL (1000 mEq/L), making it extremely hyperosmolar at approximately 2000 mOsmol/L 2
This concentration is used for bolus administration in specific emergencies such as cardiac arrest, severe hyperkalemia, or sodium channel blocker toxicity 1, 2
To obtain 150 mEq of sodium bicarbonate, you need 150 mL of the 8.4% solution 2
Clinical Context for 150 mEq Dosing
The American Heart Association recommends initial bolus doses of 50-150 mEq for sodium channel blocker/tricyclic antidepressant toxicity, using the 1000 mEq/L (8.4%) hypertonic solution 2
For continuous infusion therapy, guidelines recommend preparing a 150 mEq/L solution (not 150 mEq total) by diluting sodium bicarbonate, then infusing at 1-3 mL/kg/hour 2
Concentration-Specific Safety Considerations
For pediatric patients under 2 years of age, 8.4% solution must be diluted 1:1 with normal saline to achieve a 4.2% concentration (0.5 mEq/mL) before administration 1, 2
Children ≥2 years and adults may receive undiluted 8.4% solution, though dilution is often performed for additional safety 2
The hypertonic nature of 8.4% solution carries risks including hyperosmolarity, hypernatremia, and potential worsening of cerebral perfusion in critically ill patients 2
Practical Dosing Framework
Standard adult bolus: 1-2 mEq/kg IV (equivalent to 1-2 mL/kg of 8.4% solution) given slowly 1, 2
For a 75 kg adult: This translates to 75-150 mEq (75-150 mL of 8.4% solution) 2
Pediatric bolus: 1-2 mEq/kg IV given slowly, using appropriately diluted concentration based on age 1, 2
The confusion likely arises from the 150 mEq/L concentration used for continuous infusions versus the 150 mEq bolus dose sometimes given in toxicological emergencies—these are distinct clinical applications of sodium bicarbonate therapy. 2