A 23-year-old woman with type 1 diabetes mellitus during the 2nd week of community-acquired pneumonia developed nausea and vomiting. In the evening she has lost her consciousness and was hospitalized. Objectively, the patient's skin is pale and dry. Her respiration is loud, the tongue is dry, with brown deposit. Her heart rate is 129/min., blood pressure is 85/50 mm Hg. Palpation of the patient's abdomen provokes no response. The liver is +3 cm. Acetone test is markedly positive, blood glucose is 26 mmol/L. Make the provisional diagnosis: