When to administer sodium bicarbonate (NaHCO3) for acidosis?

From the Guidelines

Sodium bicarbonate should be administered in cases of severe acidosis, defined as arterial pH < 7.1 and base excess < −10, or in special situations such as cardiac arrest associated with hyperkalaemia or tricyclic antidepressant overdose, with a recommended dose of 50 mmol (50 ml of an 8.4% solution) 1.

Key Considerations

• The use of sodium bicarbonate in acidosis is still uncertain, with much of the evidence against its routine use based on animal studies 1.
• The administration of sodium bicarbonate should be judicious and limited to severe cases, as it can cause complications such as paradoxical intracellular acidosis, hypernatremia, hyperosmolarity, and volume overload 1.
• Treatment should always focus primarily on addressing the underlying cause of acidosis, with sodium bicarbonate reserved for severe cases where immediate pH correction is necessary to prevent hemodynamic instability, arrhythmias, or decreased effectiveness of vasopressors.

Dosage and Administration

• The recommended dose of sodium bicarbonate is 50 mmol (50 ml of an 8.4% solution), with further administration dependent on the clinical situation and the results of repeat arterial blood gas analysis 1.
• Administration should be slow, usually over 10-15 minutes, except in cardiac arrest where it may be given as a bolus.

Monitoring and Follow-up

• Regular monitoring of blood gases and electrolytes is essential during treatment with sodium bicarbonate 1.
• The patient's clinical situation and response to treatment should be closely monitored, with adjustments made to the dosage and administration of sodium bicarbonate as needed.

From the FDA Drug Label

In cardiac arrest, a rapid intravenous dose of one to two 50 mL vials (44.6 to 100 mEq) may be given initially and continued at a rate of 50 mL (44. 6 to 50 mEq) every 5 to 10 minutes if necessary (as indicated by arterial pH and blood gas monitoring) to reverse the acidosis. In less urgent forms of metabolic acidosis, Sodium Bicarbonate Injection, USP may be added to other intravenous fluids The amount of bicarbonate to be given to older children and adults over a four-to-eight-hour period is approximately 2 to 5 mEq/kg of body weight - depending upon the severity of the acidosis as judged by the lowering of total CO2 content, blood pH and clinical condition of the patient Bicarbonate therapy should always be planned in a stepwise fashion since the degree of response from a given dose is not precisely predictable Initially an infusion of 2 to 5 mEq/kg body weight over a period of 4 to 8 hours will produce a measurable improvement in the abnormal acid-base status of the blood.

Administration of Sodium Bicarbonate (NaHCO3) for Acidosis:

• In cardiac arrest, administer a rapid intravenous dose of 44.6 to 100 mEq initially, and continue at a rate of 44.6 to 50 mEq every 5 to 10 minutes as necessary.
• In less urgent forms of metabolic acidosis, administer 2 to 5 mEq/kg of body weight over a 4 to 8 hour period.
• Bicarbonate therapy should be planned in a stepwise fashion, with the initial dose producing a measurable improvement in the abnormal acid-base status of the blood 2. Key Considerations:
• Monitor blood gases, plasma osmolarity, arterial blood lactate, hemodynamics, and cardiac rhythm in metabolic acidosis associated with shock.
• Avoid attempting full correction of low total CO2 content during the first 24 hours of therapy to prevent unrecognized alkalosis.

From the Research

Administration of Sodium Bicarbonate for Acidosis

• Sodium bicarbonate (NaHCO3) administration for acidosis is a controversial topic, with some studies suggesting its use in specific scenarios while others advise against routine use 3, 4, 5, 6, 7.
• According to a study published in the Journal of the American Society of Nephrology, bicarbonate should be given at an arterial blood pH of ≤7.0, with the amount calculated to bring the pH up to 7.2 3.
• A review published in The Journal of Emergency Medicine suggests that sodium bicarbonate can be beneficial in certain scenarios, such as patients with concomitant acute kidney injury and lactic acidosis, or those with cardiac arrest secondary to sodium channel blockade or hyperkalemia 4.
• A systematic review published in Cureus found limited benefit from bicarbonate therapy for patients with severe metabolic acidosis, but noted that it may improve survival in patients with accompanying acute kidney injury 5.
• An international observational study published in Critical Care found that early sodium bicarbonate administration was associated with improved outcomes in patients with vasopressor dependency, but not in the overall population with metabolic acidosis 6.
• A literature update published in Critical Care Research and Practice noted that the use of sodium bicarbonate in sepsis patients with acidosis is controversial, with a trend towards not using bicarbonate in patients with arterial blood gas pH > 7.15 7.

Specific Scenarios for Sodium Bicarbonate Administration

• Patients with chronic bicarbonate loss, such as those with renal tubular acidosis syndromes or diarrhea, may benefit from bicarbonate replacement 3.
• Patients with acute lactic acidosis and ketoacidosis may benefit from bicarbonate therapy if the clinical situation improves 3.
• Patients with nongap acidosis may benefit from sodium bicarbonate supplementation 4.
• Patients with cardiac arrest secondary to sodium channel blockade or hyperkalemia may benefit from sodium bicarbonate therapy 4.
• Patients with vasopressor dependency and metabolic acidosis may benefit from early sodium bicarbonate administration 6.