Stat head CT (non-contrast)
Capillary glucose measurement to rule out hypoglycemia as the cause of altered mental status
Cerebral edema in DKA
Physiologic stress response 
Diabetic ketoacidosis 
Diabetes mellitus 
Diabetic ketoacidosis
Nonketotic hyperglycemia
Alcoholic ketoacidosis
Hyperosmolar hyperglycemic state 