What is the treatment for lactic acidosis?

Treatment of Lactic Acidosis

Immediate Management: Treat the Underlying Cause First

The primary treatment of lactic acidosis is identifying and aggressively treating the underlying cause—sodium bicarbonate administration lacks evidence for improving outcomes and may cause harm. 1

The cornerstone of management involves:

• Restore tissue perfusion immediately with fluid resuscitation (15-20 mL/kg/h isotonic saline initially) if shock is present 1
• Treat sepsis aggressively with source control, antibiotics within 3 hours, and hemodynamic support 1
• Discontinue offending medications immediately, including metformin, NRTIs (stavudine, didanosine), or other causative drugs 1, 2
• Ensure adequate oxygenation and mechanical ventilation if needed to reduce oxygen demand 3

The Bicarbonate Controversy: Do NOT Use It

The Surviving Sepsis Campaign explicitly recommends AGAINST using sodium bicarbonate to improve hemodynamics or reduce vasopressor requirements in hypoperfusion-induced lactic acidemia with pH ≥7.15. 1

Critical evidence against bicarbonate use:

• Sodium bicarbonate does not improve hemodynamics or cardiovascular function 1
• May increase lactate production, cause hypernatremia and volume overload, and generate CO₂ 1
• Has never been shown to improve survival 1, 4
• The oft-cited rationale that bicarbonate might ameliorate hemodynamic depression has been disproved convincingly 4

Exception: The FDA label indicates sodium bicarbonate may be considered in "severe primary lactic acidosis" where rapid increase in plasma CO₂ content is crucial, though this contradicts the strongest guideline evidence 5. Given the lack of survival benefit and potential harm, avoid bicarbonate unless pH <7.15 with life-threatening hemodynamic instability.

Specific Clinical Scenarios

Metformin-Associated Lactic Acidosis (MALA)

• Discontinue metformin immediately 1, 2
• Hemodialysis is the definitive treatment for MALA and often reverses symptoms (metformin is dialyzable with clearance up to 170 mL/min) 1, 2, 6
• Initiate hemodialysis promptly when lactate >5 mmol/L with severe acidosis or when routine measures are ineffective 2, 7
• Consider continuous kidney replacement therapy as an alternative 6
• Before restarting metformin post-recovery, ensure lactic acidosis has resolved and eGFR is ≥30 mL/min/1.73 m² 6

NRTI-Induced Lactic Acidosis (HIV Patients)

• Discontinue NRTIs immediately (stavudine, didanosine) due to high mortality without intervention 1
• Provide supportive care with fluid resuscitation and hemodynamic support 1
• Monitor for mitochondrial toxicity complications 1

D-Lactic Acidosis (Short Bowel Syndrome)

• Restrict mono/oligosaccharides and encourage polysaccharides (starch) 1
• Administer thiamine supplements 1
• Give broad-spectrum antibiotics to reduce bacterial fermentation 1

Sepsis-Related Lactic Acidosis

• Obtain blood cultures and administer antibiotics within 3 hours 1
• Initiate fluid resuscitation (1-2 L crystalloids in 60-90 minutes) if signs of tissue hypoperfusion 1
• Repeat lactate measurement within 6 hours to evaluate trend 1
• Monitor closely for progression to septic shock even without hypotension 1

Mesenteric Ischemia

• Consider CT angiography immediately if lactate >2 mmol/L with abdominal pain and elevated urea—do not delay, as diagnostic delay is the dominant mortality factor (30-70%) 1
• Lactate >2 mmol/L associates with irreversible intestinal ischemia (HR 4.1) 1
• Consider urgent laparotomy if signs of intestinal perforation 1

Supportive Care Measures

• Consider thiamine supplementation to address pyruvate dehydrogenase dysfunction 1
• Ensure adequate sedation and mechanical ventilation to reduce oxygen demand 4
• Monitor and correct electrolyte abnormalities, particularly hyperkalemia in rhabdomyolysis-induced lactic acidosis 1

Critical Monitoring Parameters

• Serial lactate measurements every 2-6 hours to assess response 1
• Arterial blood gas with pH and bicarbonate 1
• Anion gap calculation (Na - [Cl+CO₂]; >16 indicates lactic acidosis) 1, 3
• Renal function (creatinine, eGFR) and hepatic function 1
• Hemodynamic parameters and tissue perfusion markers 1

Common Pitfalls to Avoid

• Do NOT ignore hyperlactatemia (≥2 mmol/L) even without hypotension—it may indicate occult tissue hypoperfusion or organ dysfunction 1
• Do NOT use sodium bicarbonate routinely—it lacks survival benefit and may worsen outcomes 1, 4
• Do NOT delay imaging in suspected mesenteric ischemia—lactate elevation with abdominal pain demands urgent CTA 1
• Do NOT restart metformin until acidosis resolves and renal function is adequate (eGFR ≥30 mL/min/1.73 m²) 6
• Do NOT overlook medication-induced causes—review all medications, especially metformin, NRTIs, and other mitochondrial toxins 1, 8