A 62-year-old woman is rushed to the emergency room following an automobile accident. She has suffered internal injuries and massive bleeding and appears to be in a state of profound shock. Her temperature is 37degC (98.6degF), respirations are 42 per minute and blood pressure is 80/40 mm Hg. Physical examination shows cyanosis and the use of accessory respiratory muscles. A CT scan of the chest is normal on arrival. Her condition is complicated by fever, leukocytosis and a positive blood culture for staphylococci (sepsis). Two days later, the patient develops rapidly progressive respiratory distress and a pattern of "interstitial pneumonia" can be seen on a chest X-ray. Which of the following is the most likely diagnosis?