What is the role of Sodium bicarbonate in metabolic acidosis?

From the Guidelines

Sodium bicarbonate plays a crucial role in the management of metabolic acidosis, particularly in patients with chronic renal failure or those undergoing dialysis.

Key Points

• The goal of management is to maintain serum bicarbonate levels at or above 22 mmol/L to prevent acidemia and its associated complications, such as increased protein degradation and decreased albumin synthesis 1.
• Oral supplementation with sodium bicarbonate, typically 2-4 g/d or 25-50 mEq/d, can effectively increase serum bicarbonate concentrations in patients with metabolic acidosis 1.
• Correction of acidemia due to metabolic acidosis has been associated with improved outcomes, including increased serum albumin, decreased protein degradation rates, and increased plasma concentrations of branched-chain amino acids 1.
• However, the use of sodium bicarbonate therapy in other contexts, such as sepsis or diabetic ketoacidosis, is not recommended due to lack of evidence supporting its effectiveness and potential risks, such as sodium and fluid overload 1.

Important Considerations

• The decision to use sodium bicarbonate therapy should be individualized based on the patient's specific condition and needs.
• Regular monitoring of serum bicarbonate levels and adjustment of therapy as needed is crucial to prevent complications associated with metabolic acidosis.
• Other treatment strategies, such as dialysate lactate or bicarbonate levels and oral sodium bicarbonate, may also be effective in raising serum bicarbonate levels in patients with metabolic acidosis 1.

From the Research

Role of Sodium Bicarbonate in Metabolic Acidosis

• Sodium bicarbonate has been used to treat various pathologies, including hyperkalemia, cardiac arrest, and metabolic acidosis 2.
• The use of sodium bicarbonate in metabolic acidosis is controversial, with some studies suggesting potential benefits, such as reversing acidosis-induced myocardial depression and hemodynamic instability 2, 3.
• However, other studies have raised concerns about the potential harm of excessive sodium bicarbonate administration, including paradoxical respiratory acidosis, intracellular acidosis, and hypokalemia 2, 4.

Clinical Evidence

• A retrospective observational study found that early sodium bicarbonate administration was associated with higher mean arterial pressure at 6 hours and a lower odds ratio for ICU mortality in patients with vasopressor dependency 3.
• A double-blind, randomized, placebo-controlled pilot study found that sodium bicarbonate improved acid-base status, but did not improve the rate of return of spontaneous circulation or good neurologic survival in out-of-hospital cardiac arrest patients with severe metabolic acidosis 5.
• A propensity score-matched analysis found no significant difference in ICU mortality between patients with metabolic acidosis who received sodium bicarbonate and those who did not 6.

Potential Benefits and Risks

• Potential benefits of sodium bicarbonate in metabolic acidosis include:
  • Reversing acidosis-induced myocardial depression and hemodynamic instability 2, 3
  • Improving acid-base status 5
• Potential risks of sodium bicarbonate in metabolic acidosis include:
  • Paradoxical respiratory acidosis, intracellular acidosis, and hypokalemia 2, 4
  • Hypercapnia, hypokalemia, ionized hypocalcemia, and QTc interval prolongation 4