Euglycaemic ketoacidosis after fasting in a 58-year-old man with diabetes

A 58-year-old man presented to the emergency department with a 24-hour history of nausea, vomiting, and diffuse abdominal pain. He had a background of type 2 diabetes mellitus and hypertension. His regular medications were metformin 500 mg twice daily, dapagliflozin 10 mg once daily, and lisinopril 10 mg once daily. He had been taking dapagliflozin for the past 3 months; metformin and lisinopril had been prescribed for several years. In preparation for a scheduled colonoscopy, he had been fasting from 08:00 the previous day and took his usual morning medications that day. Over the following hours he became increasingly unwell with repeated vomiting and documented ketonuria at home. On arrival at the hospital he was markedly dehydrated, with a blood pressure of 105/65 mmHg, heart rate 110 beats/minute, respiratory rate 28 breaths/minute, and oxygen saturation of 96% on room air. He was drowsy but rousable. The arterial blood gas showed pH 7.18, bicarbonate 10 mmol/L, and pCO2 2.1 kPa. His blood glucose was only 12 mmol/L, with capillary ketones of 5.0 mmol/L. Serum sodium was 128 mmol/L, potassium 5.2 mmol/L, creatinine 120 µmol/L, and lactate 1.2 mmol/L. Chest radiograph and urine cultures were negative. The clinical picture was consistent with euglycaemic diabetic ketoacidosis. He was treated with intravenous 0.9% sodium chloride and an insulin infusion; dapagliflozin was withheld. Over the next 36 hours his ketones cleared and the acidosis resolved. He made a full recovery. No rechallenge with the drug was performed. A diagnosis of metformin-associated lactic acidosis was considered, but the normal lactate excluded it.