A 50 year old obese female is taking oral hypoglycemic agents. While being treated for an upper respiratory infection, she develops lethargy and is brought to the emergency room. On physical exam, there is no focal neurologic finding or neck rigidity. Laboratory results are as follows:
Na−: 134 meq/L
K−: 4.0 meq/L
HCO3: 25 meq/L
Glucose: 900 mg/dL
BUN: 84 mg/dL
Creatinine: 3.0 mg/dL
BP: 120/80 sitting, 105/65 lying down
The most likely cause of this patient’s coma is
a. Diabetic ketoacidosis
b. Hyperosmolar coma
c. Inappropriate ADH
d. Bacterial meningitis
