Sodium Bicarbonate Infusion Dilution and Administration
Concentration and Dilution Guidelines
For pediatric patients under 2 years of age, sodium bicarbonate 8.4% must be diluted 1:1 with normal saline to achieve a 4.2% concentration before administration. 1
Age-Specific Concentration Requirements
- Newborn infants: Use only 0.5 mEq/mL (4.2%) concentration; dilute available 8.4% stock solutions 1:1 with normal saline or sterile water as necessary 1, 2, 3
- Children ≥2 years and adults: May use 8.4% solution without dilution, though dilution is often performed for safety 1, 4
Standard Dilution Protocols
For severe metabolic acidosis (pH <7.1):
- Adults with pH 6.9-7.0: Dilute 50 mmol sodium bicarbonate in 200 mL sterile water 1
- Adults with pH <6.9: Dilute 100 mmol sodium bicarbonate in 400 mL sterile water 1
For continuous infusion therapy:
- Prepare 150 mEq NaHCO3/L solution for maintenance infusions in sodium channel blocker toxicity 2, 3
- Standard preparation: 100 mL of 8.4% sodium bicarbonate diluted in 150 mL normal saline within a 250 mL polyolefin bag remains stable for 48 hours 5
Administration Rate Guidelines
Bolus Dosing
Standard initial dose:
- Adults: 1-2 mEq/kg (1-2 mL/kg of 8.4% solution) IV administered slowly 2, 4
- Children: 1-2 mEq/kg IV given slowly 1, 2, 3
- Pediatric range: 1-3 mEq/kg for some indications 2
Cardiac arrest dosing:
- Initial: 44.6-100 mEq (one to two 50 mL vials of 8.4%) given rapidly 4
- Repeat: 50 mL (44.6-50 mEq) every 5-10 minutes as indicated by arterial pH and blood gas monitoring 4
Infusion Rates for Severe Acidosis
For pH <6.9:
- Infuse 100 mmol in 400 mL sterile water at 200 mL/h 1
For pH 6.9-7.0:
- Infuse 50 mmol in 200 mL sterile water at 200 mL/h 1
For less urgent metabolic acidosis:
- Administer 2-5 mEq/kg over 4-8 hours 4
- Protocol recommends 125-250 mL per infusion over 30 minutes, maximum 1000 mL within 24 hours 6
For sodium channel blocker toxicity:
Critical Safety Considerations
Administration Precautions
Never mix sodium bicarbonate with:
Monitoring Parameters During Infusion
Target endpoints:
- Maintain arterial pH above 7.30 during active therapy 6
- Avoid serum sodium >150-155 mEq/L 2
- Avoid serum pH >7.50-7.55 2
- Monitor serum bicarbonate every 2-4 hours during active infusion 3
- Continue infusion until serum bicarbonate reaches ≥22 mmol/L 3
Common Pitfalls to Avoid
Overly rapid correction: In non-emergent situations, attempting full correction of acidosis within the first 24 hours can cause unrecognized alkalosis due to delayed ventilatory readjustment 4. Target total CO2 of approximately 20 mEq/L at end of first day, which typically correlates with normal blood pH 4.
Inadequate ventilation: Bicarbonate produces excess CO2 that must be eliminated through ventilation 2. Always establish effective ventilation before administering bicarbonate, as failure to do so causes paradoxical intracellular acidosis 2.
Hypertonic solutions in cardiac arrest: While bicarbonate solutions are hypertonic and may cause undesirable plasma sodium elevation, in cardiac arrest the risks from acidosis exceed those of hypernatremia 4.
Clinical Context for Use
Bicarbonate is indicated for:
- Severe metabolic acidosis with pH <7.1 and base deficit <-10 2
- Hyperkalemia (to shift potassium intracellularly) 2
- Tricyclic antidepressant overdose with cardiac toxicity 2
- Documented metabolic acidosis after establishing adequate ventilation 2
Bicarbonate is NOT routinely indicated for:
- Diabetic ketoacidosis with pH ≥7.0 2
- Sepsis-related lactic acidosis with pH ≥7.15 2, 3
- Cardiac arrest (routine use not recommended) 2
- Tissue hypoperfusion-related acidosis 2
The best method of reversing acidosis remains treating the underlying cause and restoring adequate circulation 2, 3.