Fat Embolism Syndrome (FES)
Eva Xia
Spring 2010
Some definitions…
Fat Emboli: Fat particles or droplets
that travel through the circulation
Fat Embolism: A process by which fat
emboli passes into the bloodstream and
lodges within a blood vessel.
Fat Embolism Syndrome (FES):
serious manifestation of fat embolism
occasionally causes multi system
dysfunction, the lungs are always
involved and next is brain
Causes of FES
• Blunt
Trauma
– Long bone
(Femur,
tibia, pelvic)
factures
Causes of FES
• Non Trauma: agglutination of chylomicrons and VLDL by
high levels of plasma CRP.
– disease-related
• Diabetes, acute pancreatitis, burns, SLE, sickle cell crisis
– drug-related
• parenteral lipid infusion
– procedure-related
• Orthopedic surgery, liposuction
Pathophysiology of FES
Exact mechanism unknown, but two main
hypothesis
1. Mechanical Hypothesis
2. Biochemical Hypothesis
Mechanical Hypothesis
Obstruction of vessels and capillaries
• Increase in intermedullary pressure forces fat and marrow into
bloodstream
• Bone marrow contents enter the venous system and lodge in the lungs as
emboli
• Smaller fat droplets may travel through the pulmonary capillaries into the
systemic circulation: Embolization to cerebral vessels or renal vessels also
leads to central nervous system and renal dysfunction
Biochemical Hypothesis
Toxicity of free fatty acids
• circulating free fatty acids directly affect the
pneumocytes, producing abnormalities in gas
exchange
• Coexisting shock, hypovolemia and sepsis
impair liver function and augment toxic effects
of free fatty acids
Clinical Manifestations
Asymptomatic for the first 12-48 hours
Pulmonary Dysfunction
• Respiratory Failure and ARDS (tachypnea, dyspnea, crackles,
cyanosis)
• Hypoxemia
• systemic arterial hypotension, a decrease in cardiac output, and
arrhythmias
Neurological (nonspecific)
• acute confusion, headache, stupor, coma, rigidity or convulsions
Dermatological Signs
• A reddish brown petechial rash within 24-36 hours
• distributed to the upper body, chest, neck, upper arm, axilla,
shoulder, oral mucous membranes and conjunctivae
Clinical Manifestation
Diagnosis
• Clinical examination preferred over diagnostic
Laboratory Studies
• Arterial Blood Gases (ABGs)
• Urine and sputum examination
• Haemotological Tests
• Biochemical tests
Imagining
• Chest x-ray
– shows multiple flocculent shadows (snow storm appearance).
picture may be complicated by infection or pulmonary edema.
• CT Scan brain
– may be normal or may reveal diffuse white-matter petechial
haemorrhages
• Helical CT Scan chest
– may be normal as the fat droplets are lodged in capillary beds.
Can detect lung contusion, acute lung injury, or ARDS may be
evident.
Chest X-ray
ER admit
AP & expiratory film so we cannot comment
on cardiac shadow. However, there is no
evidence of lung contusion, pneumo, haemo
or pneumohaemothorax.
SICU admit (12 hours later)
upper lobe diversion and
bilateral pulmonary
infiltrates
Altaf Hussain: “A Fatal Fat Embolism.” The Internet Journal of Anesthesiology, 2004. Volume 8 Number 2.
MRI showing foci of ischemia
suggestive of fat embolism syndrome
post operative day 2
showing multiple
hyperintense areas
consistent with multiple
emboli
post operative day 14 and
shows evolving cortical
infarctions
Source:http://www.ispub.com/journal/the_internet_journal_of_anesthesiology/volume_19_number_2/article/acute_fatal_fat_embolism_syndrome_in_bilateral_total_knee_arthroplasty_a_review_of_the_fat_embolism_syndrome.html
Treatment
Prophylaxis
• Immobilization and early internal fixation of fracture
• High doses of corticosteroids
Medical
• Self limiting disease. Support treatment for cardiovascular and respiratory
issues
• Maintenance of intravascular volume
– Albumin is recommended
• Adequate analgesia
• Heparin
Risk Factors
Prognosis
• Most death contributed to pulmonary
dysfunction
• Hard to determine exact mortality rate
• Estimated less than 10%
House M.D Clip
Pulmonary Dysfunction
• Respiratory Failure and ARDS (tachypnea,
dyspnea, crackles, cyanosis)
• Hypoxemia
• systemic arterial hypotension, a decrease in
cardiac output, and arrhythmias
Sources
Altaf Hussain: “A Fatal Fat Embolism.” The Internet Journal of Anesthesiology, 2004. Volume 8
Number 2.
Fabian T. “Unraveling the fat embolism syndrome”. N Engl J Med 1993;329:961–63
U. Galway, J. E. Tetzlaff & R. Helfand : “Acute Fatal Fat Embolism Syndrome In Bilateral Total Knee
Arthroplasty – A Review Of The Fat Embolism Syndrome”. The Internet Journal of
Anesthesiology. 2009 Volume 19 Number 2
Latif, A., Bashir, A., Aurangzeb. "Fat Embolism and Fat Embolism Syndrome; Management Trends."
Professional Med J 15.4 (2008): 407-413.