Fat Embolism eMedicine Vascular Surgery

Description: In 1862, Zenker first described this syndrome at autopsy. In 1873, von Bergmann clinically diagnosed fat embolism syndrome for the first time.
Pathophysiology Two theories about the syndrome exist. First, the mechanical theory states that large fat droplets are released into the venous system. These droplets are deposited in the pulmonary capillary beds and travel through arteriovenous shunts to the brain. Microvascular lodging of droplets produces local ischemia and inflammation, with concomitant release of inflammatory mediators, platelet aggregation, and vasoactive amines. Second, the biochemical theory states that hormonal changes caused by trauma and/or sepsis induce systemic release of free fatty acids as chylomicrons. Acute-phase reactants, such as C-reactive proteins, cause chylomicrons to coalesce and create the physiologic reactions described above. The biochemical theory helps explain nontraumatic forms of fat embolism syndrome.
Synonyms and related keywords: fat embolism syndrome, FES, fat emboli, fat embolus, fat droplet in venous system, blunt trauma, fracture complication, blunt trauma complication, altered mental status
Lisa Kirkland, MD 2007