A 65-year-old woman fell and sustained a pelvic fracture. After a short period of rapidly progressive mental confusion and respiratory insufficiency, the woman died. Numerous conjunctival petechiae were noted. These abnormalities were most likely due to which one of the following conditions?
A. Epidural hematoma
B. Aspiration pneumonia
C. Fat embolization
D. Acute tubular necrosis
E. Saddle embolus occluding bifurcation of pulmonary arteries
The answer is C The fat embolism syndrome occurs 2 to 3 days after severe fracture injury and includes progressive CNS dysfunction and severe respiratory insufficiency. Thrombocytopenia with petechial bleeding is common, and petechial hemorrhages can result from obstruction of the microvasculature by embolic fat droplets. Respiratory insufficiency may be due to injury to pulmonary microvessels with leakage of fluid into the alveoli, resulting in ARDS.