What is sodium bicarbonate used for?

Sodium Bicarbonate: Clinical Uses and Indications

Sodium bicarbonate is primarily indicated for the treatment of metabolic acidosis and specific toxicological emergencies, but is not recommended for routine use in cardiac arrest due to potential adverse effects and limited evidence of benefit. 1

Primary Indications

Sodium bicarbonate is indicated for:

• Metabolic acidosis from:

  • Severe renal disease
  • Uncontrolled diabetes
  • Circulatory insufficiency due to shock or severe dehydration
  • Severe primary lactic acidosis 1

• Toxicological emergencies:

  • Tricyclic antidepressant overdose (first-line therapy)
  • Salicylate poisoning
  • Methanol poisoning
  • Barbiturate poisoning 2, 1

• Other specific indications:

  • Severe diarrhea with bicarbonate loss
  • Hemolytic reactions requiring urine alkalinization
  • Hyperkalemia (acute management) 1, 3

Use in Special Circumstances

Tricyclic Antidepressant Overdose

• Indicated for QRS prolongation >120 ms, hypotension, ventricular dysrhythmias, and seizures
• Initial dose: 1-2 mEq/kg IV bolus of 8.4% solution
• Titrate to resolution of QRS prolongation and hypotension 2

Chronic Kidney Disease

• Recommended to maintain serum bicarbonate at or above 22 mmol/L
• Corrects acidemia which can increase protein degradation and decrease albumin synthesis 3

Rhabdomyolysis

• Used to alkalinize urine to prevent acute kidney injury from myoglobinuria 3

Not Recommended For

Cardiac Arrest

• Routine use in cardiac arrest is not recommended (Class III, LOE B)
• May be considered only in special situations:
  • Preexisting metabolic acidosis
  • Hyperkalemia
  • Tricyclic antidepressant overdose 3

Hypoperfusion-Induced Lactic Acidemia

• Not recommended for pH ≥ 7.15 to improve hemodynamics or reduce vasopressor requirements 3

Dosing Guidelines

• Initial dose: 1 mEq/kg for special situations 3
• For TCA overdose: 1-2 mEq/kg IV bolus, repeated as needed 2
• For chronic acidosis: Oral dose of 2-4 g/day (25-50 mEq/day) 3

Potential Adverse Effects

Sodium bicarbonate administration can cause:

• Extracellular alkalosis shifting the oxyhemoglobin curve
• Hypernatremia and hyperosmolarity
• Excess CO₂ production
• Paradoxical intracellular acidosis
• Hypocalcemia
• Inactivation of simultaneously administered catecholamines
• Reduced systemic vascular resistance 3, 4

Recent Evidence

The BICAR-ICU trial (2018) found that in patients with severe metabolic acidemia:

• No overall effect on composite outcome in general population
• Decreased mortality in the subgroup of patients with acute kidney injury 5

Clinical Decision Algorithm

1. Assess the cause of acidosis:

   • If due to cardiac arrest: Not recommended unless special circumstances exist
   • If due to toxicological emergency (TCA, salicylates): Administer promptly
   • If due to metabolic causes: Consider based on severity

2. Check pH and bicarbonate levels:

   • If pH < 7.1 or bicarbonate < 10 mEq/L: Consider administration
   • If pH ≥ 7.15 with lactic acidosis: Not recommended

3. Monitor during administration:

   • Arterial blood gases
   • Serum electrolytes (especially sodium, potassium, calcium)
   • ECG for cardiac patients

4. Titrate to effect:

   • Aim for pH > 7.2 rather than complete normalization
   • Avoid overcorrection to prevent iatrogenic alkalosis

Remember that the best method of reversing acidosis is treating the underlying cause rather than simply administering sodium bicarbonate 3.