Metformin Associated Lactic Acidosis and Euglycemic Diabetic Ketoacidosis: A Case Report

Abstract

Diabetic ketoacidosis is a common complication of diabetes traditionally defined as a triad of hyperglycemia (>250 mg/dl), anion gap acidosis, and positive serum or urine ketones. However, a rare complication which requires a high level of clinical suspicion is euglycemic diabetic ketoacidosis. Patients will still present with an anion gap acidosis and positive serum or urine ketones but then will have a blood glucose level less than 200 mg/dl. We present a case with a patient who presented with metformin-associated lactic acidosis and euglycemic ketoacidosis (MALKA). Our patient presented with seizure-like activity, slurred speech, and diffuse weakness when laboratory results revealed a high anion gap metabolic acidosis with concomitant metabolic and respiratory alkalosis. She was noted to have an elevated lactate which resolved with sodium bicarbonate. However, her anion gap persisted, and she was positive for urine ketones suggesting the possible diagnosis of euglycemic DKA. The patient was started on a continuous infusion of insulin with dextrose which subsequently helped resolve her persistent anion gap acidosis. Despite a standardized protocol for treatment of diabetic ketoacidosis, MALKA remains a challenging diagnosis to make without high clinical suspicion and ruling out other possible diagnoses. The goal of this case is to enhance clinician’s diagnostic framework for anion gap metabolic acidosis.