How to administer a sodium bicarbonate infusion?

How to Administer Sodium Bicarbonate Infusion

Sodium bicarbonate should be administered as a slow intravenous bolus of 1-2 mEq/kg (using 8.4% solution in adults or 4.2% diluted solution in children under 2 years), followed by continuous infusion of 150 mEq/L solution at 1-3 mL/kg/h if ongoing alkalinization is needed, with careful monitoring to avoid hypernatremia (>150-155 mEq/L) and excessive alkalemia (pH >7.50-7.55). 1, 2

Concentration Selection and Preparation

Adult Patients

• Use 8.4% sodium bicarbonate solution (1 mEq/mL) without dilution for bolus administration 3
• For continuous infusion, prepare 150 mEq/L solution by adding sodium bicarbonate to D5W or normal saline 2
• Each 50 mL vial of 8.4% contains 44.6-50 mEq 3

Pediatric Patients

• Children ≥2 years: May use 8.4% solution, though dilution is often performed for safety 2
• Children <2 years: Must dilute 8.4% solution 1:1 with normal saline to achieve 4.2% concentration (0.5 mEq/mL) 2
• Newborn infants: Only use 0.5 mEq/mL (4.2%) concentration—dilute 8.4% stock 1:1 with normal saline or sterile water 2

Initial Bolus Dosing

Standard Metabolic Acidosis (pH <7.1)

• Adults: 1-2 mEq/kg IV administered slowly (50-100 mEq or one to two 50 mL vials) 2, 3
• Children: 1-2 mEq/kg IV given slowly 2
• Administer over several minutes, not as rapid push 2

Sodium Channel Blocker/TCA Toxicity

• Adults: Initial bolus of 50-150 mEq (using 1000 mEq/L hypertonic solution) 1, 2
• Children: Initial bolus of 1-3 mEq/kg IV (using 500 mEq/L solution) 2
• Titrate to resolution of QRS prolongation and hypotension 1

Cardiac Arrest

• Initial dose: One to two 50 mL vials (44.6-100 mEq) given rapidly 3
• Repeat dosing: 50 mL (44.6-50 mEq) every 5-10 minutes as indicated by arterial pH and blood gas monitoring 3
• Only administer after effective ventilation is established 2

Continuous Infusion Protocol

When to Start Infusion

• After initial bolus in sodium channel blocker toxicity requiring ongoing alkalinization 1, 2
• For severe metabolic acidosis requiring sustained correction over 4-8 hours 3

Infusion Preparation and Rate

• Standard concentration: 150 mEq sodium bicarbonate per liter of solution 2
• Infusion rate: 1-3 mL/kg/h of the 150 mEq/L solution 2
• Alternative for severe acidosis: 2-5 mEq/kg over 4-8 hours 3

Specific Clinical Scenarios

• Diabetic ketoacidosis (pH <6.9): 100 mmol in 400 mL sterile water at 200 mL/h 2
• Diabetic ketoacidosis (pH 6.9-7.0): 50 mmol in 200 mL sterile water at 200 mL/h 2

Critical Administration Guidelines

IV Line Compatibility

• Never mix with: Calcium-containing solutions, vasoactive amines (norepinephrine, epinephrine, dopamine), or blood products 2, 4, 5
• Flush IV line with normal saline before and after bicarbonate administration to prevent catecholamine inactivation 2
• Use separate IV lines or different ports of multi-lumen catheter when administering with incompatible medications 4, 5

Administration Rate Considerations

• Administer slowly to minimize complications 2, 3
• In cardiac arrest, rapid infusion is acceptable despite hypertonic nature, as risks from acidosis exceed those of hypernatremia 3
• For non-emergent situations, infuse over 4-8 hours 3

Monitoring Requirements

Essential Parameters

• Arterial blood gases: Check every 2-4 hours initially to assess pH, PaCO2, and bicarbonate response 2
• Serum sodium: Monitor frequently to prevent hypernatremia; target <150-155 mEq/L 1, 2
• Serum pH: Avoid exceeding 7.50-7.55 1, 2
• Serum potassium: Monitor and treat hypokalemia, as bicarbonate therapy causes potassium shift intracellularly 1, 2
• Serum ionized calcium: May decrease with bicarbonate administration 2

Clinical Monitoring

• Hemodynamic parameters and vasopressor requirements 3
• Cardiac rhythm, especially QRS duration in toxicity cases 1
• Signs of fluid overload 4
• Adequacy of ventilation to eliminate excess CO2 produced 2

Repeat Dosing Strategy

Guided by Clinical Response

• Do not attempt full correction in first 24 hours—target total CO2 of ~20 mEq/L initially to avoid overshoot alkalosis 3
• Repeat dosing should be guided by arterial blood gas analysis, not given empirically 2
• In sodium channel blocker toxicity, give additional boluses as needed for recurrent QRS prolongation or hypotension 1

When to Stop

• Resolution of severe acidosis (pH >7.15-7.2) 2
• Achievement of hemodynamic stability and normal QRS duration in toxicity cases 1
• Development of hypernatremia (>150-155 mEq/L) or alkalemia (pH >7.50-7.55) 1

Special Clinical Situations

Contraindications and Cautions

• Do not use routinely in: Cardiac arrest without specific indication, hypoperfusion-induced lactic acidemia with pH ≥7.15, diabetic ketoacidosis with pH ≥7.0 2
• Avoid in respiratory acidosis: Bicarbonate increases CO2 production and may worsen respiratory acidemia 6
• Use with extreme caution in: Patients with inadequate ventilation, as CO2 elimination is required 2

Preferred Scenarios for Use

• Life-threatening TCA/sodium channel blocker cardiotoxicity (Class I recommendation) 1
• Severe hyperkalemia as adjunct to glucose/insulin 2
• Rhabdomyolysis with myoglobinuria for urine alkalinization 2
• Documented severe metabolic acidosis (pH <7.1) with adequate ventilation 2

Common Pitfalls to Avoid

• Administering without adequate ventilation: Bicarbonate produces CO2 that must be eliminated; ensure effective ventilation first 2
• Mixing with catecholamines: Alkaline solution inactivates epinephrine, norepinephrine, and dopamine 2, 5
• Rapid correction: Overshoot alkalosis occurs due to delayed ventilatory readjustment 3
• Using in septic lactic acidosis with pH ≥7.15: No mortality benefit and potential harm from sodium/fluid overload 2
• Forgetting to monitor potassium: Bicarbonate causes hypokalemia that requires treatment 1
• Using hypertonic solution in young children: Always dilute to 4.2% in children <2 years 2