Immediate Management of Severe Lactic Acidosis in a Diabetic Patient on Metformin and Empagliflozin
Stop metformin immediately and initiate urgent hemodialysis for this patient with severe metformin-associated lactic acidosis (MALA), as the dextrose of 13 mmol/L (234 mg/dL) with vomiting, diarrhea, and dizziness strongly suggests acute dehydration and acute kidney injury precipitating life-threatening lactic acidosis. 1
Critical First Steps
Discontinue all oral antidiabetic medications immediately:
- Metformin must be stopped at once due to suspected MALA 1
- Empagliflozin (Jardiance) should be held as SGLT2 inhibitors can worsen dehydration and precipitate euglycemic diabetic ketoacidosis 2
- The combination of gastrointestinal symptoms with dehydration creates the perfect storm for metformin accumulation 3, 4
Urgent Diagnostic Workup
Obtain these laboratory values stat:
- Arterial blood gas with lactate level (MALA is confirmed when lactate >5 mmol/L with high anion gap metabolic acidosis) 1, 5
- Serum creatinine and eGFR to assess acute kidney injury 1, 5
- Serum ketones (beta-hydroxybutyrate) to rule out concurrent euglycemic DKA from SGLT2 inhibitor 2
- Anion gap calculation 1, 5
- Metformin level if available (typically >5 mcg/mL in MALA) 1
Immediate Therapeutic Interventions
Initiate aggressive supportive care:
- Start IV fluid resuscitation immediately to correct prerenal acute kidney injury and improve metformin clearance 6, 5
- Consider bicarbonate-buffered IV fluids if severe acidosis is confirmed (pH <7.1) 7, 6
- Transfer to intensive care unit for close hemodynamic monitoring 8, 5
Prepare for urgent renal replacement therapy:
- Hemodialysis is the definitive treatment for severe MALA and should be initiated promptly 1, 7, 8
- Metformin is dialyzable with clearance up to 170 mL/min under good hemodynamic conditions 1
- Continuous venovenous hemodiafiltration (CVVHDF) is an alternative that corrects acidosis without risk of fluid overload 7
- Multiple hemodialysis sessions may be required given the severity of presentation 8
Clinical Context and Risk Factors
This patient has multiple risk factors for MALA:
- Acute dehydration from vomiting and diarrhea reduces renal clearance of metformin 3, 4, 1
- Gastrointestinal symptoms suggest "sick day" scenario where metformin should have been temporarily discontinued 3
- The FDA black box warning specifically identifies dehydration, vomiting, and diarrhea as precipitating factors for lactic acidosis 1
Mortality considerations:
- MALA carries a 30-50% mortality rate if not promptly treated 4, 5
- Cases with pH <7.0 and lactate >30 mmol/L have been successfully treated with prompt hemodialysis 8
- Early recognition and aggressive intervention are critical for survival 7, 6
Concurrent SGLT2 Inhibitor Concerns
Evaluate for euglycemic diabetic ketoacidosis:
- SGLT2 inhibitors like empagliflozin can cause euDKA even with blood glucose <250 mg/dL 2
- The combination of metformin overdose/accumulation and SGLT2 inhibitor use may produce both lactic acidosis and ketoacidosis simultaneously 2
- Check serum ketones even if glucose is not markedly elevated 2
Contraindications to Metformin Restart
Do not restart metformin until:
- Lactic acidosis has completely resolved 5
- Renal function has recovered with eGFR ≥30 mL/min/1.73 m² 3, 4
- Patient is clinically stable without ongoing gastrointestinal symptoms 3
- If eGFR is 30-45 mL/min/1.73 m², reduce dose to maximum 1000 mg daily 3, 4
Key Clinical Pitfalls to Avoid
Common errors in MALA management:
- Delaying hemodialysis while attempting medical management alone—this increases mortality 1, 8
- Failing to recognize that "sick day rules" require temporary discontinuation of metformin during acute illness 3
- Missing concurrent euglycemic DKA from SGLT2 inhibitor use 2
- Restarting metformin too early before confirming adequate renal recovery 5