A 54-year-old woman with long-standing rheumatoid arthritis is scheduled to undergo a left total knee replacement. Her current medications are acetaminophen, naproxen, prednisone, and methotrexate. Blood pressure is 140/90. Cardiopulmonary examination shows no abnormalities. Creatinine is 1.2 mg/dL. Which of the following studies is most appropriate prior to surgery?
ACTH stimulation test
Antibody assay for cyclic citrullinated peptide
Dexamethasone suppression test
Flexion and extension x-rays of cervical spine
Spirometry
