A patient with severe metformin-associated lactic acidosis complicated by acute coronary syndrome: a case report

INTRODUCTION: Metformin-associated lactic acidosis (MALA) is a rare but life-threatening condition. Here, we report the outcome of a patient with MALA complicated by acute coronary syndrome. CASE PRESENTATION: A 47-year-old obese woman of Caucasian ethnicity was admitted for syncope and tachypnea with Kussmaul breathing. She had a type-2 diabetes and was on oral antidiabetic therapy. Hemoglobin A1c was 6.6%. On admission, a severe acute kidney injury (serum creatinine: 1251 µmol/L) with hyperkalemia (7.5 mmol/L) and severe lactic acidosis (ph:7.042, bicarbonate: 9.9 mmol/L, partial pressure of carbon dioxide: 21.8 mmHg, lactate: 20.0 mmol/L) was found. Despite bicarbonate therapy, ph further decreased. Within 2.5 h of admission, a temporary hemodialysis catheter was placed, and one session of a high-efficiency hemodialysis was performed. 8 h after admission, a continuous venovenous hemodiafiltration was initiated and maintained for 2 days. The metformin therapy was stopped. Supplemental oxygen, intravenous catecholamines (4 days) and antibiotic therapy (7 days) were applied. During this therapy of lactic acidosis, an acute coronary syndrome evolved by day 2 after admission and resolved by day 5 in hospital. After recovery, the patient was transferred to a general ward on day 7 and left the hospital on day 11. By discharge, both the acute kidney injury and the acute coronary syndrome were reversible. CONCLUSION: In the patient with MALA complicated by acute coronary syndrome, the combination of a high-efficiency hemodialysis and, consecutively, continuous venovenous hemodiafiltration led to a favorable outcome.