The WBC count was 10,300 cells/μL, with 82% neutrophils, 16% bands, and 1% lymphocytes. The hemoglobin concentration was 8.2 g/dL, and the platelet count was 36,000 cells/μL with rare schistocytes in the peripheral smear and 3.5% reticulocytes. Prothrombin time was 16.3 s, and partial thromboplastin time was 38 s. Electrolytes were normal; creatinine, 2.01 mg/dL; BUN, 58 mg/dL; aspartate aminotransferase, 66 U/L; alanine aminotransferase, 271 U/L; serum lactate dehydrogenase (LDH), 2,769 U/L; lactate, 5.1 mmol/L; total bilirubin, 1 mg/dL; and indirect bilirubin, 0.5 mg/dL. Arterial blood gas analysis performed with an 80% fraction of inspired oxygen revealed the following: pH, 7.089; Paco2, 66 mm Hg; Pao2, 208 mm Hg; HCO3 concentration, 18 mmol/L; and oxygen saturation, 98%. A chest radiograph (Fig 1
) showed bilateral airspace disease to be most dense in the right mid-lung zone.