A 24-year old man presents to the emergency department complaining of nausea, vomiting and abdominal pain. His wife reports that he has an altered level of consciousness. His symptoms began several days ago when he complained of “the flu.” He went to an urgent care and was started on an antibiotic and prednisone for ‘walking pneumonia’. He is confused, hypotensive, and breathing rapidly and deeply. He also has appeared to be drinking and urinating more than usual. His past medical history is significant for psychosis and he is currently taking risperdal. On examination, the patient appears pale and ill. His temperature is 98.9 °F, pulse rate is 154 beats per minute, blood pressure (BP) is 86/44 mm Hg, and respiratory rate is 36 breaths per minute. On examination, his eyes are sunken, and he has dry mucous membranes. There is an unusual odor to his breath. Lungs are clear bilaterally with regular, deep respirations. Cardiac examination is notable for tachycardia. The abdomen is diffusely tender to palpation. Skin is cool and dry with decreased turgor. Laboratory studies show: Serum glucose is 820 mg/dL, sodium 136 mEq/L, potassium 5.4 mEq/L, chloride 94 mEq/L, bicarbonate 14 mEq/L, blood urea nitrogen (BUN) 23 mg/dL, creatinine (Cr) 1.2 mg/dL, Anion gap was computed to be 28. Arterial blood gas was notable for pH 7.25. Urinalysis was remarkable for large glucose and ketones. Complete blood count (CBC) showed a leukocyte count of 16,700 cells/mcL. A 12-lead electrocardiogram (ECG) shows only sinus tachycardia. His chest x-ray (CXR) is normal.
