How to treat lactic acidosis?

Treatment of Lactic Acidosis

The treatment of lactic acidosis should focus on identifying and treating the underlying cause, discontinuing any causative medications, providing supportive care, and in severe cases, implementing renal replacement therapy when conventional treatments fail. 1, 2

Assessment and Classification

• Lactic acidosis is characterized by elevated blood lactate concentrations (>2 mmol/dL), with levels of 2-5 mmol/dL considered elevated and requiring correlation with symptoms 2
• Levels >5 mmol/dL are abnormal, and levels >10 mmol/dL indicate serious and potentially life-threatening situations 2
• Laboratory evaluation may reveal an increased anion gap (Na − [Cl+CO2] >16), elevated aminotransferases, creatine phosphokinase, lactic dehydrogenase, lipase, and amylase 2

First-Line Management

• Identify and treat the underlying cause of lactic acidosis, which is the cornerstone of treatment 3, 4
• Immediately discontinue any medications that may be causing or contributing to lactic acidosis, particularly metformin in cases of metformin-associated lactic acidosis 5
• Provide general supportive measures promptly in a hospital setting, ensuring adequate oxygen delivery to tissues and reducing oxygen demand through sedation and mechanical ventilation if necessary 5, 6

Specific Interventions

• For metformin-associated lactic acidosis:

  • Immediately discontinue metformin 5
  • Institute prompt hemodialysis to correct acidosis and remove accumulated metformin (metformin is dialyzable with clearance up to 170 mL/min under good hemodynamic conditions) 5

• For hypoperfusion-induced lactic acidemia:

  • Sodium bicarbonate therapy is not recommended for patients with hypoperfusion-induced lactic acidemia with pH ≥ 7.15 as evidence shows no improvement in hemodynamic variables or vasopressor requirements 2, 1
  • Sodium bicarbonate can have adverse effects including sodium and fluid overload, increased lactate and PCO2, and decreased serum ionized calcium 1, 6

• For severe, refractory lactic acidosis:

  • Consider continuous renal replacement therapy (CRRT) or hemodialysis, particularly in patients with:
    • Severe acidosis unresponsive to conventional treatment 1, 7
    • Concurrent acute kidney injury 1, 2
    • Hemodynamic instability requiring fluid management 2, 7
  • CRRT and intermittent hemodialysis are considered equivalent in efficacy for patients with sepsis and acute renal failure 2, 1

Special Considerations

• In HIV-infected patients with NRTI-induced lactic acidosis, consider administering thiamine and riboflavin in addition to discontinuing antiretroviral treatment 2
• For patients with severe lactic acidosis manifested by tachypnea and dyspnea, intensive therapeutic strategies including bicarbonate infusions and hemodialysis may be necessary 2
• Avoid overlooking medication-induced causes of lactic acidosis, particularly in patients with renal impairment 1, 5

Monitoring

• Monitor serum bicarbonate and electrolytes for early identification of an increased anion gap 2
• In patients at risk for lactic acidosis, consider monitoring every 3 months 2
• When measuring lactate levels, use standardized sample handling:
  • Use prechilled fluoride-oxalate tubes
  • Transport immediately on ice to the laboratory
  • Process within 4 hours after collection
  • Collect blood without using a tourniquet, without fist-clenching, and if possible, without stasis 2

Prevention in High-Risk Patients

• For patients on metformin:
  • Assess renal function before initiating therapy and regularly thereafter 5
  • Avoid metformin in patients with eGFR <30 mL/min/1.73 m² 5
  • Use caution in patients with eGFR between 30-45 mL/min/1.73 m² 5
  • Temporarily discontinue metformin during procedures with restricted food and fluid intake 5
  • Stop metformin prior to iodinated contrast imaging procedures in high-risk patients 5