What is the recommended intravenous (IV) dose of sodium bicarbonate for a patient with severe acidosis or during cardiac arrest?

Sodium Bicarbonate IV Dosing

For severe metabolic acidosis (pH < 7.1 and base excess < -10), administer 50 mmol (50 mL of 8.4% solution) IV initially, with further doses guided by repeat arterial blood gas analysis; in cardiac arrest, give 1-2 mEq/kg (44.6-100 mEq) as a rapid IV bolus, repeatable every 5-10 minutes based on arterial pH monitoring. 1, 2, 3

Primary Dosing Guidelines

Standard Adult Dosing for Severe Metabolic Acidosis

• Initial dose: 50 mmol (50 mL of 8.4% solution) administered intravenously 1, 2, 4
• Alternative dosing: 1-2 mEq/kg IV (typically 50-100 mEq or 50-100 mL of 8.4% solution) given slowly over several minutes 2, 3
• Further administration depends on clinical response and repeat arterial blood gas analysis, targeting pH 7.2-7.3 rather than complete normalization 1, 2

Cardiac Arrest Dosing

• Rapid initial dose: One to two 50 mL vials (44.6-100 mEq) given as rapid IV bolus 3
• Repeat dosing: 50 mL (44.6-50 mEq) every 5-10 minutes as indicated by arterial pH and blood gas monitoring 3
• Administer only after first dose of epinephrine has been ineffective 2

Pediatric Dosing

• Standard dose: 1-2 mEq/kg IV given slowly 2, 4
• Newborns: Use only 0.5 mEq/mL (4.2%) concentration; dilute 8.4% solution 1:1 with normal saline or sterile water 2
• Children under 2 years: Dilute 8.4% solution to 4.2% concentration before administration 2

Specific Clinical Scenarios

Sodium Channel Blocker/Tricyclic Antidepressant Toxicity

• Initial bolus: 50-150 mEq using hypertonic solution (1000 mEq/L) 2
• Continuous infusion: 150 mEq/L solution at 1-3 mL/kg/hour to maintain alkalosis 2
• Target arterial pH 7.45-7.55 and monitor for QRS narrowing 2

Hyperkalemia

• Dose: 1-2 mEq/kg IV as temporizing measure while definitive therapy is initiated 2
• Combine with glucose/insulin for synergistic effect 2

Diabetic Ketoacidosis

• pH < 6.9: 100 mmol sodium bicarbonate in 400 mL sterile water infused at 200 mL/hour 2
• pH 6.9-7.0: 50 mmol sodium bicarbonate in 200 mL sterile water infused at 200 mL/hour 2
• Do NOT use if pH ≥ 7.0 2

Less Urgent Metabolic Acidosis

• Dose: 2-5 mEq/kg body weight over 4-8 hours 3
• May be added to other intravenous fluids 3
• Adjust based on severity of acidosis as judged by total CO2 content, blood pH, and clinical condition 3

Critical Contraindications and Cautions

When NOT to Use Sodium Bicarbonate

• Do NOT use for hypoperfusion-induced lactic acidemia with pH ≥ 7.15 2, 4
• Do NOT use routinely in cardiac arrest without specific indications 2, 5, 6
• Avoid in diabetic ketoacidosis with pH ≥ 7.0 2, 4

Specific Indications Where Bicarbonate IS Recommended

• Severe metabolic acidosis with pH < 7.1 AND base excess < -10 1, 2, 4
• Cardiac arrest associated with hyperkalemia 1, 2
• Tricyclic antidepressant or sodium channel blocker overdose 1, 2
• Documented metabolic acidosis in specific toxicologic emergencies 1, 2

Administration Technique and Safety

Preparation and Dilution

• Adults and children ≥2 years: May use 8.4% solution without dilution, though dilution is often performed for safety 2
• Children <2 years: Must dilute 8.4% to 4.2% concentration (1:1 with normal saline) 2
• Newborns: Use only 0.5 mEq/mL (4.2%) concentration 2

Administration Rate

• Administer as slow IV push over several minutes for non-arrest situations 2, 3
• In cardiac arrest, may give as rapid bolus 3
• Flush IV line with normal saline before and after administration to prevent catecholamine inactivation 2

Critical Safety Warnings

• Never mix with calcium-containing solutions or vasoactive amines (causes precipitation/inactivation) 2
• Ensure adequate ventilation before administration to eliminate excess CO2 produced 1, 2
• Bicarbonate solutions are hypertonic and may cause undesirable rise in plasma sodium 3

Monitoring Requirements

Essential Parameters to Monitor Every 2-4 Hours

• Arterial blood gases: pH, PaCO2, bicarbonate 2, 7
• Serum electrolytes: Sodium (target <150-155 mEq/L), potassium, ionized calcium 2
• Clinical response: Hemodynamic parameters, cardiac rhythm 2, 3

Treatment Targets

• Target pH: 7.2-7.3, NOT complete normalization 1, 2
• Avoid: pH >7.50-7.55 (excessive alkalemia) 2
• Avoid: Serum sodium >150-155 mEq/L (hypernatremia) 2

When to Stop or Adjust Therapy

• Achievement of target pH 7.2-7.3 2
• Resolution of QRS prolongation and hemodynamic stability in toxicity cases 2
• Development of hypernatremia or excessive alkalemia 2
• Severe hypokalemia requiring replacement 2

Common Pitfalls to Avoid

Physiologic Complications

• Paradoxical intracellular acidosis: Occurs if adequate ventilation not established before bicarbonate administration 1, 2
• Hypokalemia: Bicarbonate shifts potassium intracellularly; monitor and replace as needed 2
• Hypocalcemia: Large doses decrease ionized calcium, affecting cardiac contractility 2
• Hypernatremia and hyperosmolarity: From hypertonic solution administration 2, 3

Clinical Decision Errors

• Attempting full correction of acidosis in first 24 hours (may cause unrecognized alkalosis due to delayed ventilatory readjustment) 3
• Using bicarbonate for tissue hypoperfusion-related acidosis when pH ≥7.15 (no benefit, potential harm) 2, 8
• Routine use in cardiac arrest without specific indications (associated with worse outcomes) 5, 6

Drug Interactions

• Simultaneous administration with catecholamines causes inactivation 1, 2
• Mixing with calcium-containing solutions causes precipitation 2

Duration of Therapy

• Continue until serum bicarbonate reaches ≥22 mmol/L in chronic metabolic acidosis 7
• In severe acidosis (pH <7.0), continue until pH rises above 7.0, then reassess 7
• For cardiac arrest, discontinue once spontaneous circulation restored and acidosis corrected 7
• Monitor for metabolic alkalosis (pH >7.45) indicating overcorrection 7