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Fat Embolism Syndrome (FES)
(in medical science till today)
Dr. Puneet Sharma
M.B.B.S., D.Ortho., DNB(Ortho.)
Kalika hospital, Pathankot
Fat Embolism, an entity first described as early
as 1862, has remained a mystery to the medical
science till date
The abstruseness on diverse aspects of its
patho-physiology and management has been
well-acknowledged
Fat embolism in humans was first recognized in 1861 by Zenker who
described fat droplets in the lung of a railroad worker who had suffered
a fatal thoraco-abdominal crush injury.
Zenker FA. Beitrage zur Anatomie und Physiologie der Lunge. J Braundorf 1861.
Twelve years later, Von Bergmann in 1873 clinically diagnosed fat
embolism syndrome (FES) in a patient with a fractured femur.
Von Bergmann EB. Ein fall todlicher fettembolie. Klan Wochenschr 1873; 10: 385–7.
Fat Emboli
Fat droplets that travel through the circulation
Fat droplets
“Fat Embolism”
Fat Embolism: A process by which fat emboli passes into the
bloodstream and travel within a blood vessel.
"Fat Embolic Syndrome" (FES)
The "Fat Embolic Syndrome" (FES) is defined as the
occurrence of injury and dysfunction of one or more
organs, caused by the occurrence of a Mechanical
blockage or Biochemical injury to vascular capillaries
caused by circulating droplets of fat with diameters
about 8 to 10 microns, usually getting trapped in the
capillary meshwork.
This is a complication or a non-typical evolution of FE
• It is usually asymptomatic, but a few patients will
develop signs and symptoms of multi-organ
dysfunction, particularly involving the triad of lungs,
brain, and skin.
• A small percentage of these patients develop
picture similar to ARDS, this was recognized as
FES long before ARDS entered into medical
literature
Incidence
Surprisingly, the incidence was 0.9% when only clinical criteria
were used to diagnose FES
Whereas with the aid of postmortem examination the incidence
was as high as 20%.
The incidence of FES ranges from
< 1 to 29% in different studies.
Bulger et al. in their retrospective study, reported an incidence of < 1%
Fabian et al. in their prospective study, reported an incidence of 11–29%
Mortality from FES has been reported to be
as high as 20 percent
Mainstays of Treatment in “FES”
Early diagnosis
Low tidal volume with PEEP
Supportive treatment
Causes of “Fat Embolism”
Severe traumas of the subcutaneous tissue
Hiss et al. Beaten to death: why do they die? J Trauma 1996; 40:27-30.
Liposuction and perinasal autologous fat injection
Scroggins C et al. Md Med J 1999; 48:116-8.
Ross AP et al. Surgery 2009; 65:271-3.
Trauma
Non -Traumatic Causes
Acute pancreatitis,
Fatty liver,
Corticosteroid therapy,
Lymphography,
Fat emulsion infusion
Haemoglobinopathies.
Saldeen et al. J Trauma 1970; 10:273-86.
Masson et al. Chest 1985; 88:908-14.
Capan et al. Anesthesiol Clin North Am 1993
Mudd et al. J.Trauma 2000; 48:711-715.
PATHOPHYSIOLOGY
2 Theories
Mechanical…… (Baker et al)
Biochemical….. (Lehman et al)
Mechanical Theory
(Baker et al)
Systems affected include Lungs,
Brain and Any Organ via
circulation.
Fat droplets are deposited in the
pulmonary capillary beds and travel
through arteriovenous shunts to the
brain.
Mechanical Theory………….
Micro-vascular lodging of droplets
Local ischemia and inflammation
Release of inflammatory mediators, platelet
aggregation, and vasoactive amines.
Mechanical Block
Biochemical Theory
(Lehman et al)
Hormonal changes caused by trauma and/or sepsis
induce systemic release of free fatty acids (FFA) as
chylomicrons which cause the systemic FES.
FES is dependent upon degradation of
the embolized fat  free fatty acids.
Biochemical Theory……….
The FFAs acts locally to produce an increase in the permeability
of the capillary bed, a destruction of the alveolar architecture,
and damage to lung surfactant.
Onset of symptoms may coincide
with Agglutination.
The delay in onset of symptoms may
be due to the time required for the
production of toxic metabolites.
CRP (acute phase reactant), which is elevated in trauma patients,
appears to be responsible in lipid agglutination for
both traumatic and non-traumatic FES.
RISK FACTORS
Young age,
Closed fractures,
Multiple fractures, and conservative therapy for
long-bone fractures.
Risk is especially high with femoral shaft fracture
and concomitant head injury;
Clinical Presentation
Diagnosis is made “Clinically NOT Chemically”
It does not matter how much fat globules are in the
circulation, it just matters if pt have their side effects.
FES typically manifests 24 to 72 hours after the
initial insult. Rarely <12 hrs or >72 hrs.
Classic triad:
Hypoxemia
Neurologic abnormalities
Petechial Rash
Clinical Presentation……….
The number of clinically evident cases of respiratory distress
represents the tip of the iceberg, with a large number of lung
injury remaining clinically inapparent
Pulmonary dysfunction is the earliest to manifest
Seen in 75% of patients
Progresses to respiratory failure in 10% of the cases.
Respiratory dysfunction is major cause of
mortality, which is about 10-20%.
Clinical Presentation & Investigations of “FES” Count….
LUNGS
Respiratory Insufficiency
pH ..
PaCO2..
ABG
HCO3…
PaO2…
Lactate…
ABG analysis showing an unexplained increase in pulmonary shunt
fraction and an alveolar-to-arterial oxygen tension difference,
especially within 24–48 h of a sentinel event associated with FES, is
strongly suggestive of the diagnosis.
Clinical Presentation & Investigations of “FES” Count….
LUNGS
X-ray Chest
A diffuse bilateral infiltrate i.e. “Snow Storm Appearance”,
predominant on basal and per-hillar regions, and usually appears only
about 24 to 48 h after trauma . This radiological aspect, although
'typical' of FES, is found in only 30 to 50% of the cases and cannot
be considered as pathognomonic of this syndrome
Capan LM, Miller SM, Patel KP. Fat embolism. Anesthesiol Clin North Am 1993; 11:25-54.
Clinical Presentation & Investigations of “FES” Count….
LUNGS
CT-Chest
Ground glass
opacification with
interlobular septal
thickening
“FES” affects the lung in a Heterogeneous
fashion
Clinical Presentation & Investigations of “FES” Count….
LUNGS
Pulmonary Perfusion Scintiscan
Normal perfusion
lung scan
Pulmonary embolism.
(a) Perfusion scan shows multiple areas of ischemia.
(b) Ventilation image using Xe, shows normal aeration of
both lungs.
This set of findings is considered pathognomonic of
pulmonary embolism.
Clinical Presentation & Investigations of “FES” Count….
Brain
Anxiety, Confusion, Convulsions, irritability…Coma
70 to 80% cases
MRI - Brain
“star field pattern”
MRI showing hyper intense areas
foci of ischemia suggestive of fat
embolism syndrome
Clinical Presentation & Investigations of “FES” Count….
Autopsy finding of Brain showing foci
of Petechial Hemorrhages suggestive of
fat embolism syndrome
Autopsy finding
of Brain
Clinical Presentation & Investigations of “FES” Count….
SKIN
Incidence between 20% and 60% in FES
This is embolization of small dermal
capillaries leading to extravasations
of erythrocytes. It has no relation to
platelets. This produces Petechial
rash ( 1mm to 2mm) in the
conjunctiva,
oral
mucosal
membranes, Skin folds of upper body
parts as neck, axilla, chest.
It is Self Limiting
Resolve in 36 h to 7 days
Fat globules float and therefore
distributed to branches of the aorta
that arise from the top of the aortic
arch that are uppermost
Clinical Presentation & Investigations of “FES” Count….
The retina
50% cases
Clinical Presentation & Investigations of “FES” Count….
LABORATORY CHANGES
ANEMIA ---The reduction of hematocrit, (70% of patients) without
apparent hemorrhage, within the first or second day after trauma
THROMBOCYTOPENIA: -- Decrease Platelet (< 1.5 Lacks)occurring only in about 30%
to 50% of the cases
FAT DROPLETS :------ in Blood, Urine, Broncho-alveolar wash
SERUM FREE FATTY ACID:----- increases
SERUM LIPASE:----- increases
ESR :----- increases
These changes are "typical" of FES
But they are not unique or diagnostic of this syndrome
Since FES is not predictable preoperatively, one of the
study proposed that intraoperative guidelines can be used
to reduce risk of this complication.
How we detect that really “Emboli” are
generated during IM Fracture Fixation
Trans- Esophegeal Echo Cardiography
(TEEC)
Atrial Blood Sampling
Diagnostic Criteria's
FES is a “Clinical diagnosis”
There are Three imp. Criteria in literature:1…..
Gurd and Wilson's criteria
2…… Schonfeld’s Scoring criteria
3…..
Lindeque’s Criteria
Gurd and Wilson's criteria
( 2 Major
or
1 Major + 4 Minor ) required to diagnose FES.
Schonfeld’s Scoring criteria
A score of more than 5 is required to diagnose FES.
Lindeque’s Criteria
Early, reliable, utilitarian predictive factors for fat embolism syndrome in
polytrauma patients
-Nirmal raj gopinath et al; Indian J Crit Care Med. 2013 Jan-Feb; 17(1): 38–42.
Concludes
Patients presenting with a triad:
1) polytrauma (NISS >17)
2) raised initial serum lactate and
3) even a transient episode of hypoxia
These poly-trauma Pt. are at a higher risk for developing
FES/post-traumatic hypoxia
Fat embolic syndrome may present with a wide spectrum
of acute lung injury severity, with oxygenation
impairment ranging from mild asymptomatic reduction in
oxygen saturation to ARDS with severe shunt physiology
Bosse MJ, et.al. J Bone Joint Surg Am 1997;79:799 - 809.
Current concepts of respiratory insufficiency syndromes
after fracture. J Bone Joint Surg Br 2001;83:781 - 791.
TREATMENT
Hypertonic Glucose:---- reduces the concentration of circulating fatty acids
Human Albumin:----- chelating free fatty acids
Heparin
Dextran-40
Ethylic Alcohol:----- Alcohol had the ability of reducing serum lipase activity and,
consequently, of reducing the release of fatty acids.
Nitric Oxide Therapy - in Fat Embolism Syndrome to Prevent Right Heart Failure;
(E. Brotfain et al Case Rep Crit Care. 2014; 2014)
DHEA (Dehydroepiandrosterone) - modulates the inflammatory response in a bilateral
femoral shaft fracture model
(P. lichte Eur J Med Res. 2014; 19(1): 27.)
No prospective and randomized
studies were found in literature
NOT Accepted as Treatment
Corticosteroids ( Controversial)
Methylprednisolone is the study drug
Methylprednisolone …30mg/kg initial dose repeated @ 4 Hours,
1gm dose repeated @ 8 Hours
( Total 3 Doses )
Key is to initiate treatment early and for a short period of
time being watchful of side effects
Its efficiency, however, has never been proved by studies and
its use is not considered in many studies.
Capan LM, et.al.Anesthesiol Clin North Am 1993; 11:25-54.
Robinson CM.et.al. J Bone Joint Surg Br 2001; 83: 781-91
"Disease with an undetermined Pathophysiology causes a non-specific treatment"
SUPPORTIVE TREATMENT
Oxygen therapy
Bronchodilator agents to overcome bronchospasm
Conservative fluid management
Endotracheal intubation with mechanical ventilation
at high inspired oxygen levels, using continuous PEEP
Fracture Fixation Technique
-Controversial• IM Nail - Reamed v/s Un-Reamed
– Decreased with Unreamed Technique
• Pape et al
– No Difference
• Keating et al
• Canadian OTS
• IM Nail Reamed v/s Plate Osteosynthesis
– No Difference In Pulmonary Dysfunction i.e. FES
• Bosse et al
Fat embolism syndrome after IM nailing an isolated open tibial fracture in a stable
patient: a case report by Gustavo Aparicio*
BMC Research Notes 2014, 7:237
TIPS to Prevent “FES” during “IM Nailing”
Drive the Nail slowly…Give pause after few blows…Give time for marrow to drain out
Enlarge the Entry point….give space to the marrow to drain out
Use the reamer in which Reamer Head size is short and with deep flutes
During reaming longitudinal velocity of reamer should be less
Using smaller diameter unreamed nails have also been shown to produce lesser lung
injury
Regarding the two most common kinds of rods - cylindrical and fluted - the cylindrical
type causes a much higher increase of IMP, and, thus, cause much more FE than fluted rods
TIPS to Prevent “FES” during “Cementing” in Arthroplasty
VENTING:
Make 4 - 6 mm-diameter hole in the diaphysis portion located at few
centimeters from the prosthesis end
RETROGRADE FILLING:-------- Filling from the distal to proximal
VISCOSITY:------------ use of low-viscosity cements
PROXIMAL VACUUM :- Applied a vacuum of 600mmHg through a metal cannula or
intramedullary catheter introduced at the intertrochanteric line
during prosthesis cementation.
PREVENTION of “FES”
Avoid hypovolemia and hypoxia
Close monitoring of the blood pressure and the PaO2
Adequate analgesia is important to limit the sympathomimetic
response to injury.
Concept of “Early Fixation" of fractures
in “Clinically Stable” Patients
With supportive care and early fixation
“FES” has a favorable outcome.
Thanks