High Anion Gap Metabolic Acidosis due to Euglycemic Diabetic Ketoacidosis Caused by Sodium-Glucose Co-transporter 2 inhibitor

The case is that of 58 year-male with type 2 diabetes mellitus for 7 years, hypertension, hypercholesterolemia, who was admitted to the hospital with left lower limb cellulitis over the past 8 days. On work-up he was found to have high aniongap metabolic acidosis (AGMA) with anion gap of 25, his lactate levels were normal (D and L-lactate). He denies overdosing with any medications and his toxicology screen for methanol, ethanol, aspirin, and ethylene glycol were negative. He has no psychiatric history of note. He denies using over the counter medications like acetaminophen. No bowel surgery could be elicited. He felt dehydrated and nauseous but otherwise fine. His medications includes; carvedalol 25mg twice daily, hydrochlothiazide 25 mg daily, Lipitor 20 mg daily, insulin, aspirin 81 mg daily, and was started on canagliflozoin 300 mg daily 4 weeks ago to control his blood sugar level and A1C. Physical examination of the patient revealed, slightly dehydrated but well-nourished man, his vital signs; heart rate of 78 BPM and regular, BP 143/85 mmHg, temperature 98.7 F, and his oxygen saturation while breathing room air was 92%. Examination of the heart, abdomen, and chest were unremarkable. He had left lower leg cellulitis but no edema or tenderness. His work-up including chemistry-7 which showed sodium of 142 mmol/L, potassium of 4.3 mmol/L, chloride of 102 mmol/L, bicarbonate of 13 mmol/L, BUN and creatinine of 18 mg/L and 0.78 mg/L respectively. His blood glucose level was 178 mg/L with A1C of 8.2. His serum osmolality was 312 mosm/L, and his arterial blood pH was 7.2 with a carbon dioxide in blood gas analysis (Pco2) of 32mmHg. His calculated anion gap was 25 given his normal albumin level. His investigation also showed positive ketones in the serum and urine. His urine PH was 5.5 and the urine contain >800 mg of glucose.