My Orthopaedic Surgeon

FES may be defined as a complex alteration of hemostasis which occurs as an infrequent complication of fractures of pelvis and or long bones and manifests clinically as acute respiratory insufficiency.
Dr. Masood Jawaid & Dr. Muhammad Naseem 2005 Pakistan Journal of Medical Sciences Volume 21 July-September 2005 Number 3

Orthopaedic Trauma Association Core Curriculum Presentation CoursePowerpoint Presentation made by well known authorities in the area and hosted by the OTA. You may use and edit these presentations for educational purposes provided you give credit to the original author and the OTA

Mr Gurd Shergill and Mr Harish Parmar Archive copy from fractures.com
Fat embolism and the associated fat embolism syndrome is a serious and potentially life threatening complication of long bone trauma, blunt trauma and intramedullary manipulation. However, some seemingly unrelated conditions have also resulting in fat embolism, such as diabetes, burns, severe infections, sickle cell anaemia, cardio pulmonary by pass, SLE and pancreatitis.

Fat embolism syndrome follows long bone fractures. Its classic presentation consists of an asymptomatic interval followed by pulmonary and neurologic manifestations combined with petechial hemorrhages. The syndrome follows a biphasic clinical course. The initial symptoms are probably caused by mechanical occlusion of multiple blood vessels with fat globules that are too large to pass through the capillaries. Unlike other embolic events, the vascular occlusion in fat embolism is often temporary or incomplete since fat globules do not completely obstruct capillary blood flow because of their fluidity and deformability. The late presentation is thought to be a result of hydrolysis of the fat to more irritating free fatty acids which then migrate to other organs via the systemic circulation.
Kirsten Odegard, MD Department of Anesthesiology New York University Medical Center

eMedicine Article (2004) by Lisa Kirkland MD (Internist)
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

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

Fat embolism syndrome, a condition characterized by hypoxia, bilateral pulmonary infiltrates, and mental status change, is commonly thought of in association with long-bone trauma. Fat embolization can frequently take place, however, within the setting of elective and semiacute orthopedic procedures.[1] In particular, there is a high incidence of fat embolization during placement of hip prostheses. Although studies suggest that embolization events infrequently result in a clinically apparent fat embolism syndrome,[1,2] clinicians should be vigilant in considering fat embolism syndrome as a causative agent of postoperative respiratory distress.
J Am Board Fam Pract 14(4):310-313, 2001.

Case reports and a review of Toronto experience. Drummond, Salter & Boone CMAJ 1969 (full text)

Wheeless' Textbook of Orthopaedics
FES results when embolic marrow fat macroglobules damage small vessel perfusion leading to endothelial damage in pulmonary capillary beds leading to respiratory failure and ARDS like picture;

Fat Embolism syndrome: A review giving most importance on its clinical manifestations, diagnosis and therapy.

Altaf Hussain: A Fatal Fat Embolism. The Internet Journal of Anesthesiology. 2004. Volume 8 Number 2.
Fat Embolism and the associated Fat Embolic Syndrome is a serious and potentially life threatening condition. It tends to occur most frequently after fractures or intramedullary instrumentation of long bones particularly the femur and tibia. Some other non-traumatic conditions such as Diabetes Mellitus sever Burns, SLE and Pancreatitis etc. can also result in Fat Embolic Syndrome. Young adults irrespective of sex are commonly affected. Its classical presentation consists of an asymptomatic interval followed by pulmonary and neurological manifestations combined with petechail haemorrhages. The diagnosis largerly depends on high index of suspicions and exclusion of other conditions. Treatment of this condition remains supportive. Mortality associated with this condition is significant, ranging from 10-20 %. Here is a description of such a fatal case.

Full text: J Clin Pathol Suppl (R Coll Pathol). 1970; 4: 123–131. G Szabó