<prompt> 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 8040 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?Acute bronchiolitisAlveolar proteinosisAtelectasisDiffuse alveolar damage  <response>: Diffuse alveolar damage DAD refers to a non specific pattern of reaction to injury of alveolar epithelial and endothelial cells from a variety of acute insults. The clinical counterpa of severe DAD is acute respiratory distress syndrome. In this disorder, a patient with apparently normal lungs sustains pulmonary damage and then develops rapid progressive respiratory failure. Desquamative interstitial pneumonia is a chronic, fibrosing, interstitial pneumonitis of unknown etiology. 