A 63-year-old male with a 23-year history of type 2 diabetes mellitus was admitted to a district general hospital with a 2-day history of vomiting, diarrhoea, anorexia, and right upper quadrant abdominal pain. The patient had previously experienced complications, including retinopathy, maculopathy, and intermittent claudication. Additionally, he had moderate COPD but remained functionally independent and had adopted a healthier lifestyle by quitting smoking and limiting alcohol consumption. His medications included metformin, aspirin, simvastatin, and twice-daily pre-mixed insulin. Canagliflozin had been introduced to his regimen 7 months before hospitalization. On admission, the patient's vital signs were stable: respiratory rate 22 breaths/min, blood pressure 117/69 mmHg, heart rate 105 bpm, oxygen saturation 95% on room air, and body temperature 37.1°C. Mild tenderness in the right upper quadrant of the abdomen was noted, but no signs of peritonism were observed. An electrocardiogram revealed anterior-lateral ST-segment depression. Finger-prick blood glucose measured 13.3 mmol/L, and the 3-hydroxybutyrate level was elevated at 5.2 mmol/L. Venous blood analysis demonstrated a pH of 7.15 and a bicarbonate level of 8 mmol/L. Notably, the patient's creatinine was mildly elevated at 79 µmol/L (baseline: 56 µmol/L), troponin I levels showed an initial normal result but later increased to 10,148 ng/L (reference range: 0–40 ng/L), and CRP was significantly elevated at 452 mg/L (reference range: 0–10 mg/L).