What is the treatment for lactic acidosis?

Treatment for Lactic Acidosis

The primary treatment for lactic acidosis includes identifying and treating the underlying cause, discontinuing offending medications, providing supportive care, and in severe cases, implementing renal replacement therapy. 1

Diagnosis and Assessment

• Lactic acidosis is characterized by:

  • Blood pH < 7.35
  • Elevated blood lactate levels (> 5 mmol/L)
  • Anion gap acidosis
  • Increased lactate:pyruvate ratio 1

• Clinical presentations include:

  • Nonspecific gastrointestinal symptoms (nausea, vomiting, abdominal pain)
  • Respiratory distress (tachypnea, dyspnea)
  • Increased somnolence
  • Generalized weakness 1, 2

Treatment Algorithm

1. Identify and Treat Underlying Cause

• Type A (hypoxic) lactic acidosis:

  • Ensure adequate tissue perfusion and oxygen delivery
  • Treat shock with fluid resuscitation
  • Maintain mean arterial pressure > 65 mmHg using vasopressors if needed 1

• Type B (non-hypoxic) lactic acidosis:

  • Discontinue offending medications:
    • Metformin: Immediately discontinue in patients with suspected lactic acidosis 2
    • NRTIs: Suspend antiretroviral treatment if clinical and laboratory manifestations of lactic acidosis syndrome occur 3
  • Treat underlying conditions (diabetic ketoacidosis, liver failure, etc.) 1

2. Supportive Care

• Provide fluid resuscitation to maintain adequate intravascular volume
• Monitor electrolytes, renal function, and serial lactate levels
• Correct coexisting electrolyte abnormalities 1
• For respiratory compromise, consider mechanical ventilation with low tidal volumes 1

3. Bicarbonate Therapy

• Generally not recommended for routine treatment of lactic acidosis 1, 4
• Consider only in severe acidosis (pH < 7.15) with hemodynamic instability 1
• If used, administer cautiously and monitor for complications:
  • Hypocalcemia
  • Volume overload
  • Paradoxical intracellular acidosis 1
• In cardiac arrest with severe acidosis, sodium bicarbonate may be administered at 1-2 vials (44.6-100 mEq) initially and continued at 44.6-50 mEq every 5-10 minutes if necessary 5

4. Renal Replacement Therapy

• Indicated for:

  • Severe metabolic acidosis unresponsive to medical management 1
  • Metformin-associated lactic acidosis (metformin is dialyzable with clearance up to 170 mL/min) 2
  • NRTI-associated lactic acidosis with severe symptoms 3

• Hemodialysis has often resulted in reversal of symptoms and recovery in metformin-associated lactic acidosis 2

• However, for other forms of lactic acidosis, the effectiveness of CRRT is limited as lactate clearance (79 mL/min) is small compared to rates of lactate overproduction in septic shock 6

Special Considerations

Medication-Specific Management

Metformin-Associated Lactic Acidosis

• Immediately discontinue metformin
• Implement prompt hemodialysis to correct acidosis and remove accumulated metformin 2
• Monitor blood gases, plasma osmolarity, arterial blood lactate, hemodynamics, and cardiac rhythm 5

NRTI-Associated Lactic Acidosis

• Suspend antiretroviral treatment
• Consider intensive therapeutic strategies including bicarbonate infusions and hemodialysis 3
• Some clinicians administer thiamine and riboflavin based on the pathophysiologic hypothesis of mitochondrial respiratory chain dysfunction, though efficacy requires clinical validation 3

Monitoring Response

• Monitor serial arterial blood gases, lactate levels, electrolytes, renal function, and hemodynamic parameters 1
• Avoid rapid or complete correction of acidosis within the first 24 hours, as this may lead to unrecognized alkalosis due to delayed ventilatory adjustment 5
• Target a total CO2 content of about 20 mEq/liter at the end of the first day of therapy 5

Pitfalls and Caveats

• Bicarbonate therapy: The rationale that it might improve hemodynamics in metabolic acidemia has been disproven 4
• Overreliance on CRRT: CRRT with high-volume hemofiltration is not effective as a primary treatment for severe lactic acidosis 6
• Delayed recognition: High mortality rates are associated with delayed recognition and failure to identify the underlying cause 1
• Measurement issues: Lactate testing requires standardized sample handling (prechilled fluoride-oxalate tubes, immediate transport on ice, processing within 4 hours) 3

By following this algorithmic approach and addressing the underlying cause while providing appropriate supportive care, clinicians can optimize outcomes in patients with lactic acidosis.