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:

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).