Fat Embolism Syndrome

Background

• Fat embolism syndrome refers to the clinical triad of deteriorating mental status, progressive respiratory insufficiency, and petechial skin rash caused by the presence of fat emboli in systemic circulation, typically following a long bone fracture or other major trauma including crush injuries or burns.
• It is reported to occur more commonly in patients aged 10-40 years, especially men.
• Fat embolism syndrome is rare, with reported incidences varying widely due to a lack of uniform diagnostic criteria, but with overall incidences of 1%-3.5% in patients with trauma, 4.8%-7.5% in those suffering bilateral femoral fractures, and up to 11% in patients treated with intramedullary nail fixation.

Evaluation

• Classic presentation is a triad of hypoxia, confusion, and petechial rash, but not all signs may be present in all patients.
• Pulmonary symptoms are usually the first to appear and skin manifestations are typically the last to appear.
• Diagnosis is typically made based on a combination of clinical history and imaging findings from chest x-ray, high-resolution computed tomography (chest and/or brain), magnetic resonance imaging (brain), and ventilation-perfusion scanning.
• Transesophageal echocardiography can reveal embolic showers suggestive of pulmonary embolism with or without increased pulmonary artery pressures in some cases.
• Blood testing may reveal unexplained anemia or thrombocytopenia and blood cytology may reveal the presence of circulating fat globules.

Management

• Fat embolism syndrome is often self-resolving with good outcomes with a reported mortality rate of ≤ 10%.
• There is no definitive therapy, but the approach may be similar to treatment of acute respiratory distress syndrome (ARDS), where treatment is generally supportive in combination with aggressive management of precipitating conditions.
• Medications are generally considered ineffective for reducing levels of circulating fat or the consequences of it.