Professor of Surgery University of Rochester, United States
Introduction: Fat embolism syndrome (FES) is rare yet causes significant morbidity and mortality in patients with long-bone fractures. We present a case of FES in a polytrauma patient where the visualization of fat emboli on lower extremity venous duplex ultrasound facilitated early recognition and definitive management.
Description: An 18-year-old healthy male presented after high impact vehicle accident with 45-minute extrication time; injuries included comminuted, displaced midshaft right femur fracture, displaced fractures of the left ischium and bilateral pubic bones, and complex facial lacerations. The right leg was placed in traction with plan for definitive operative fixation the next morning. However, CT chest revealed extensive bilateral pulmonary emboli. Subsequent venous duplex ultrasound showed no deep venous thrombosis in the lower extremities but revealed numerous mobile echogenic foci traversing the common femoral veins consistent with fat emboli. A STAT echocardiogram showed no right heart strain with negative agitated saline study. The venous ultrasound finding prompted orthopedic surgery to immediately take the patient for an intramedullary nail procedure, which he tolerated well. Thirty-six hours post-injury, he developed fever, tachycardia, tachypnea, mild hypoxemia, sudden anemia and thrombocytopenia. These signs and symptoms rapidly improved and he was discharged 7 days post-injury.
Discussion: FES is a rare syndrome that involves the release of fat globules into the bloodstream after long-bone injury. It is diagnosed clinically in patients meeting a combination of major (respiratory symptoms, neurologic abnormalities, petechial rash) and minor (tachycardia, fever, fat globules in the retina, urine, or sputum, elevated ESR, sudden anemia and thrombocytopenia) criteria. Classic patterns seen on MR head can support the diagnosis of FES, however these findings represent irreversible brain damage. This case demonstrates that venous duplex ultrasound can allow for direct visualization of fat emboli in circulation in real-time, which can assist in the diagnosis and management of FES before significant morbidity can occur. In this case, the ultrasound findings prompted early orthopedic fixation, the only known effective treatment for FES, which led to the patient’s positive outcome.
