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:
B. Congestive heart failure
C. Bronchial asthma
D. Fat Embolism
Correct answer : D. Fat Embolism
The 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 tachypnoea. There may be high spiking fever and non palpable petichae, 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).