For what medical procedures is bicarbonate (sodium bicarbonate) used?

Clinical Procedures and Indications for Bicarbonate Administration

Bicarbonate is used for specific medical procedures and conditions including severe metabolic acidosis (pH <7.0-7.1), drug intoxications (particularly tricyclic antidepressants and sodium channel blockers), life-threatening hyperkalemia, cardiac arrest in select circumstances, chronic kidney disease management, and urinary alkalinization procedures. 1, 2

Emergency and Critical Care Procedures

Cardiac Arrest Management

• Bicarbonate is NOT routinely recommended in cardiac arrest, but may be considered after the first dose of epinephrine has been ineffective in asystolic arrest 1
• Administer 1-2 mEq/kg IV given slowly only after effective ventilation has been established 1
• Repeat dosing of 50 mL (44.6-50 mEq) every 5-10 minutes may be given as indicated by arterial pH monitoring 1, 2
• Flush the IV cannula with normal saline before and after bicarbonate administration to prevent inactivation of simultaneously administered catecholamines 1

Toxicological Emergencies

• For tricyclic antidepressant overdose with QRS widening >120 ms, bicarbonate is a Class I (strongly recommended) intervention 1
• Administer 50-150 mEq bolus of hypertonic solution (1000 mEq/L), targeting arterial pH 7.45-7.55 1
• Continue with infusion of 150 mEq/L solution at 1-3 mL/kg/h to maintain alkalosis 1
• For other sodium channel blocker toxicity, use similar dosing with titration to resolution of QRS prolongation and hypotension 1
• In barbiturate, salicylate, or methyl alcohol poisoning, bicarbonate is indicated to enhance renal elimination through urinary alkalinization 2

Life-Threatening Hyperkalemia

• Bicarbonate shifts potassium intracellularly as a temporizing measure while definitive treatments are initiated 1
• Must be used in conjunction with glucose/insulin, not as monotherapy 1
• Monitor serum potassium every 2-4 hours during therapy as intracellular shift can cause significant hypokalemia requiring replacement 1

Metabolic Acidosis Management

Severe Metabolic Acidosis

• Bicarbonate therapy is indicated for severe metabolic acidosis with pH <7.0-7.1 and base deficit <-10 1, 2
• Administer 1-2 mEq/kg IV (typically 50-100 mEq or 50-100 mL of 8.4% solution) given slowly over several minutes 1
• Target pH of 7.2-7.3, not complete normalization, to avoid overshooting into alkalosis 1
• Monitor arterial blood gases every 2-4 hours to guide further administration 1

Diabetic Ketoacidosis (DKA)

• Bicarbonate is indicated ONLY if pH <6.9 in adult DKA patients 1
• For pH <6.9: infuse 100 mmol sodium bicarbonate in 400 mL sterile water at 200 mL/h 1
• For pH 6.9-7.0: infuse 50 mmol sodium bicarbonate in 200 mL sterile water at 200 mL/h 1
• Bicarbonate is NOT necessary if pH ≥7.0 1
• Important caveat: Potassium supplementation must be maintained and carefully monitored, as insulin therapy, correction of acidosis, and volume expansion all decrease serum potassium 1

Lactic Acidosis and Sepsis

• Bicarbonate is explicitly NOT recommended for hypoperfusion-induced lactic acidemia when pH ≥7.15 1
• Two blinded randomized controlled trials showed no difference in hemodynamic variables or vasopressor requirements compared to equimolar saline 1
• Consider bicarbonate only if pH <7.15, and only after ensuring adequate ventilation, optimizing hemodynamics, and treating underlying shock 1

Chronic Kidney Disease Procedures

Oral Bicarbonate Supplementation

• For chronic kidney disease patients, maintain serum bicarbonate at or above 22 mmol/L 1
• Administer oral sodium bicarbonate 2-4 g/day (25-50 mEq/day) to increase serum bicarbonate concentrations 1
• Correction of acidemia has been associated with increased serum albumin, decreased protein degradation, and fewer hospitalizations 1
• Measure serum bicarbonate at least monthly during maintenance therapy 3

Renal Tubular Acidosis

• Continue treatment until serum bicarbonate reaches ≥22 mmol/L 3
• Measure serum bicarbonate at least monthly in maintenance therapy, but more frequently (every 2-4 hours) during active correction of severe acidosis 3

Urinary Alkalinization Procedures

Rhabdomyolysis with Myoglobinuria

• Use bicarbonate to alkalinize urine and prevent acute tubular necrosis 1
• Target urine output of more than 2 mL/kg/h 1
• Goal is to make myoglobin precipitate less in alkaline urine 1
• Important caveat: Large doses may decrease free ionized calcium acutely, worsening hypocalcemia associated with crush injury 1

Hemolytic Reactions

• Bicarbonate is indicated to diminish nephrotoxicity of hemoglobin and its breakdown products through urinary alkalinization 2

Tumor Lysis Syndrome

• Alkalinization with sodium bicarbonate is only indicated for patients with documented metabolic acidosis 1

Pediatric-Specific Procedures

Concentration and Dilution Requirements

• 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
• Newborn infants require a 0.5 mEq/mL (4.2%) concentration 1, 3
• Children ≥2 years and adults may use 8.4% solution without dilution 1

Pediatric Dosing

• Standard dose for children is 1-2 mEq/kg IV given slowly 1
• For sodium channel blocker toxicity in pediatrics, initial bolus is 1-3 mEq/kg IV 1

Critical Safety Considerations and Monitoring

Absolute Contraindications During Administration

• Never mix sodium bicarbonate with calcium-containing solutions - causes precipitation 1, 3
• Never mix with vasoactive amines - causes inactivation 1, 3

Essential Monitoring Parameters

• Monitor serum sodium frequently to prevent hypernatremia (target <150-155 mEq/L) 1
• Monitor serum pH to avoid exceeding 7.50-7.55 1
• Monitor and treat hypokalemia during alkalemia therapy 1
• Monitor ionized calcium levels, particularly with doses >50-100 mEq or in patients with renal dysfunction 1
• Ensure adequate ventilation to eliminate excess CO2 produced by bicarbonate 1

Potential Adverse Effects to Monitor

• Sodium and fluid overload 1
• Extracellular alkalosis, shifting the oxyhemoglobin curve and inhibiting oxygen release 1
• Hypernatremia and hyperosmolarity 1
• Excess CO2 production causing paradoxical intracellular acidosis 1
• Decreased ionized calcium affecting cardiac contractility 1
• Increased lactate production (paradoxical effect) 1

Conditions Where Bicarbonate Should NOT Be Used

• Normal pH (7.35-7.45) - may induce or worsen alkalosis 4
• Diabetic ketoacidosis with pH ≥7.0 1
• Sepsis-related acidosis with pH >7.15 1, 4
• Severe malaria - metabolic acidosis typically resolves with correction of hypovolemia and treatment of anemia 1
• Routine use in cardiac arrest 1