Unusual case of concurrent metformin-associated lactic acidosis and euglycaemic ketoacidosis

Metformin-associated lactic acidosis (MALA) and euglycaemic diabetic ketoacidosis (EKA) are both life-threatening endocrine emergencies. MALA is a well-documented complication of anti-glycaemic therapy in diabetics while EKA is an increasingly recognized disease entity with the advent of use of sodium-glucose co-transporter-2 (SGLT-2) inhibitors. However, the occurrence of concurrent metformin-associated lactic acidosis and euglycaemic ketoacidosis (MALKA) is uncommon and rarely reported in the literature. We report an unusual case of MALKA, in a 74-year-old gentleman with no previous history of chronic kidney disease and SGLT-2 inhibitor use, who presented with altered mental status, acute renal failure and profound high anion-gap metabolic acidosis (HAGMA) with lactaemia, ketonaemia and normoglycaemia (pH 6.965, bicarbonate 3.1, creatinine 522, glucose 6.6, lactate 17.5, ketones >8). The patient was initiated on intravenous insulin infusion with dextrose-containing drip and continuous renal replacement therapy (CRRT) in the intensive care unit (ICU). The patient had a prolonged hospital stay but was eventually discharged with a normalised renal function without need for long-term dialysis. The parallel occurrence of MALA and EKA suggest a metformin-associated inhibition of gluconeogenesis. This case highlights the importance of early recognition and investigation of concurrent diabetic ketoacidosis in the presence of MALA and vice versa as MALKA benefits from both prompt institution of parenteral glucose therapy and insulin infusion and consideration of initiation of haemodialysis.