This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Fracture Neck of Femur, Subject name: Orthopaedics
[{'content': 'A 30 year old man had a road traffic accident and sustained fracture of femur. Two days later he developed sudden breathlessness. The most probable cause can be: \nSelect and explain. \nA. Pneumonia, B. Congestive heart failure, C. Bronchial asthma, D. Fat Embolism', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Ans. D. Fat EmbolismThe fat globules released from the bone marrow (due to trauma/orthopedic procedures) are deposited in the pulmonary capillary bed. This causes ischemia and inflammation. The symptoms appear 12-72 hours after the trauma. Initial symptoms are tachycardia and tachypnea. There may be high spiking fever and non-palpable petechiae, especially over upper body.Neurological symptoms like agitation, delirium, stupor and coma can occur. (The fat globules may cross the pulmonary circulation via arteriovenous connections).', 'role': 'assistant'}]