A 65-year-old woman with diabetes mellitus was undergoing treatment with metformin. Because of high blood pressure, she was taking diuretics. Gradually, the effectiveness of the diuretic decreased and nausea and vomiting appeared. Objectively the patient does not respond to stimuli, her skin is dry, the smell of acetone is absent. Blood pressure - 180/100 mm Hg. The heart sounds are muffled, pulse - 98/min. Her respiration is vesicular. The liver is +4 cm. Blood testing revealed the following glucose - 48 mmol/L, Na - 156 mmol/L K-52 mmol/L, urea 15 mmol/L. What complication has developed in the patient?