What findings would be expected on arthrocentesis?
A 64-year-old man with congestive heart failure presents to the emergency room complaining of acute onset of severe pain in his right foot. The pain began during the night and awoke him from a deep sleep. He reports the pain to be so severe that he could not wear a shoe or sock to the hospital. His current medications are furosemide, 40 mg twice daily, carvedilol, 6.25 mg twice daily, candesartan, 8 mg once daily, and aspirin, 325 mg once daily. On examination, he is febrile to 38.5°C. The first toe of the right foot is erythematous and exquisitely tender to touch. There is significant swelling and effusion of the first metatarsophalangeal joint on the right. No other joints are affected.