Case Summary
A 61-year-old with a history of gout, atrial fibrillation, Raynaud phenomenon, hypertension, and congestive heart failure presented to the emergency department with a 2-week history of gradually worsening right upper-extremity weakness and paresthesias. Physical examination revealed mildly decreased sensation and strength, greater in the right arm than in the left. The patient’s initial laboratory values were calcium, 10.1 mg/dL (nl 9–10.5); creatinine, 1.1 mg/dL; phosphorus, 5.2 mg/dL (nl 3–4.5); alkaline phosphatase, 109 U/L (nl 36–92); and lactic acid, 3.1 mmol/L (nl 0.7–1.8).