588: Rare Fulminant Mala in a Renally Intact Host: A Deadly Metabolic Mismatch

Introduction: Metformin-associated lactic acidosis (MALA) is rare, noted in less than 10 cases per 100,000 patients, with mortality exceeding 30%. We present a case of severe MALA in patient without prior chronic kidney disease, emphasizing the role of early renal replacement therapy (RRT) in reversing profound metabolic and hemodynamic derangements. Description: A 56-year-old man with type 2 diabetes mellitus (on metformin, insulin, and an SGLT2 inhibitor) and hypertension presented with acute encephalopathy and hemodynamic instability. He progressed to a shock state requiring vasopressor support and mechanical ventilation. Laboratory findings were concerning for severe acidemia (pH 8.0 mEq/L, and creatinine 8.6 mg/dL (baseline 0.6). After gathering history from family, no intentional overdose was noted. A formal diagnosis of MALA was made, and the patient was started on emergent RRT for metformin and lactic acid clearance. Over the course of a few days, the initial laboratory metformin level resulted at 58 mcg/mL (normal 15 mmol/L are associated with poor prognosis but should not delay initiation of RRT, which remains life-saving. This case adds to growing evidence that preserved baseline renal function does not eliminate the risk of life-threatening MALA.