A 28-year-old man with type 1 diabetes presents to the emergency department with 24 hours of polyuria, abdominal pain, nausea, and progressive drowsiness. He has been unwell with influenza. On examination, he is tachycardic, tachypnoeic with Kussmaul respirations, and mildly hypotensive. Venous blood gas reveals pH 7.15, bicarbonate 10 mmol/L, serum ketones are elevated, and blood glucose is 25 mmol/L. Which statement best characterises his condition?