A 43-year-old woman comes to the physician for a 3-week history of cough and fatigue. She has smoked one pack of cigarettes daily for 23 years. She has hypertension managed with hydrochlorothiazide. Blood pressure is 130/80. A chest x-ray shows several nodules throughout both lung fields. Serum studies show:
Sodium 137 mEq/L
Potassium 3.8 mEq/L
Calcium 10.3 mEq/L
Which of the following is the most appropriate next step in management?
0.45% NaCl
Bisphosphonate therapy
Fluid restriction
Glucocorticoid therapy
Synacthen test
