A 52-Year-Old Male with Fever and Rapidly Progressive Dyspnea

摘要

A 52-year-old man who had never smoked was admitted to our hospital because of severe hypoxemia of unknown origin. He had a history of high fever (about 39deg C) and dyspnea for several days. He had no prior history of lung disease and no exposure to occupational dust or animal hazards. The patient had no peripheral lymphadenopathy,no skin lesions and no neurological deficits. On abdominal examination, the liver and spleen tip were not palpable. Laboratory examination showed anemia (Hb, 7.6 g/dl), decreased platelet count (3.6 x 10~4/mm~3) and normal white blood cell count. Serum C-reactive protein level was elevated (14.3 mg/dl) and erythrocyte sedimentation rate was increased (24 mm/h). Other laboratory results included: total protein, 6.0 g/dl; serum albumin, 3.5 g/dl; serum creatinine, 1.4 mg/dl; blood urea nitrogen, 11.0 mg/dl; serum lactate dehydrogenase, 781 IU/l (markedly elevated); serum glucose concentration, normal; liver function tests, normal; serum complement prothrombintime, 53%. Arterial blood gases drawn on 4 liters O_2 given nasally were: PaO_2, 48.8 Torr; PaCO_2, 31.8 Torr; pH, 7.48; HCO_3, 24.1 mmol/l; BE, 1.3 mmol/l. Antinuclear antibodies, rheumatoid factor and antineutrophil cytoplasmicantibodies were not detected. Repeated blood,sputum, urine and stool cultures were negative for possible pathogens. The urine was negative for Legionella antigen, and the Mycoplasma pneumoniae antigen was negative. Chest radiography and high-resolution computed tomography (HRCT) were taken. Chest radiography on admission showed slightly diffuse interstitial shadows in both lung fields.