Post on 10-Apr-2018
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Lutheran Medical Center
Department of Surgery
Morbidity & Mortality Conference
Case & Topic Presentation
Baiju C. Gohil, M.D.April 9, 2004
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FAT EMBOLISM
SYNDROME
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INTRODUCTION
Fat emboli were first noted by F.A. Zenker in 1861 in arailroad worker with a thoraco-lumbar crush injury
Fat Embolism Syndrome (FES) was first described by
Von Bergman in 1873 in a diagnosis confirmed by postmortem examination
In the US, frequency of FES is unknown; clinicaldiagnosis; dx missed because of subclinical illness or
confounding injury or illness Fat embolism develops in nearly all pts with fracturedbones or during ortho procedures and is asymptomatic
In minority of pts s&s develop as a result of organdysfunction, notably lungs, brain, and skin; FES
Mortality rate 10-20%
Chest Volume 123 Number 4 April 2003
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PATHOPHYSIOLOGY
Two theories exist about FES: Mechanical theory states that large fat
droplets are released into venous system,deposit into pulmonary capillary beds, andthrough a-v shunts to the brain;microvascular lodging of droplets causes
local ischemia and inflammation Biochemical theory states that hormonal
changes caused by trauma and/or sepsisinduce systemic release of free fatty acids
and chylomicrons; acute phase reactantscause chylomicrons to coalesce and createischemia
Chest Volume 123 Number 4 April 2003
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CLINICAL SIGNS OF FES
Cardiopulmonary
Early persistent tachycardia
Tachypnea, dyspnea, and hypoxia due to V-Q abnormalities
12-72 hrs after insult High temperature spikes
Dermatological
Reddish-brown nonpalpable petechiae over upper body, esp
axillae, 24-36 hrs after insult; occur in 20-50% of pts andresolve quickly
Subconjunctival and oral hemorrhages/petechiae
Neurologic
CNS dysfunction initially manifests as agitated delirium; mayprogress to stupor, seizures, or coma; frequently unresponsiveto correction of hypoxia
Retinal hemorrhages with intra-arterial fat globules are visibleupon fundoscopic examination
Arch Surg 1997; 132:435439
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CAUSES OF FES
Blunt trauma; multiple long bone andpelvic fxs (assoc w/ 90% of FES cases)
Acute pancreatitis DM
Burns
Joint reconstruction Liposuction
Cardiopulmonary bypass
Parenteral lipid infusion
Sickle cell crisis
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WORKUP
Laboratory ABG
Thrombocytopenia, anemia, andhypofibrinogenemia are indicative of FES, butnonspecific
Urine, blood, sputum examination with Sudan or oilred O staining detect fat globules
Imaging CXR-diffuse b/l pulmonary infiltrates
Head CT-nl or diffuse white matter petechialhemorrhages
Chest CT-parenchymal changes c/w lung contusion,acute lung injury, or ARDS
V/Q scan-nl or subsegmental perfusion defects
Procedures BAL-staining of alveolar macrophages for fat
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FES: CRITERIA FOR DIAGNOSIS
Dx of FES requires at least one sign from major criteria and at least four signsfrom the minor criteria category
Gurd's Major Criteria: axillary or subconjuctival petechia; occurs transiently (4-6 hours) in 50-60 % of the cases
hypoxemia (PaO2,
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TREATMENT
Medical care Supportive in nature
Maintain oxygenation and ventilation Stabilize hemodynamics
Blood products as needed
Hydration DVT & stress related GI bleed prophylaxis
Nutrition
Surgical care Early stabilization of long bone fractures tominimize bone marrow embolization intovenous system
Arch Surg 1997; 132:435439
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CONTROVERSIES
Surg Gynecol Obstet. 1978 Sep;147(3):358-62
Corticosteroids in patients with a high risk of fat embolism
syndrome
Alho A, Saikku K, Eerola P, Koskinen M, Hamalainen M. Effects of methylprednisolone on clinical FES were studied in
series of 60 pts. who had at least two fractures of the pelvis, femur
and tibia and who did not have any other significant injuries
31 controls; 29 pts. given 10 mg/kg methylprednisolone 3 times,once at admission and, at 8 and 16 hrs post-trauma
FES defined as combination of hypoxemia, bilateral "snow storm"
infiltrations of the lungs, petechial rash, mental disturbances,
pyrexia, anemia and thrombocytopenia
Varying degrees of FES observed in 2 steroid pts. And in 15
controls
Methylprednisolone in an early pharmacologic dosage is effective
in fulminant instances of fat embolism that occur in spite of
adequate respiratory care and the proper treatment of fractures
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CONTROVERSIES
J Trauma. 1987 Oct;27(10):1173-6.
'Low-dose' corticosteroid prophylaxis against fat embolism.
Kallenbach J, Lewis M, Zaltzman M, Feldman C, Orford A, Zwi
S. 82 skeletal trauma pts. Identified as high risk for FES
42 control subjects given placebo and 40 steroid-treated subjects (9
mg/kg methylprednisolone)
Fat embolism occurred in ten controls (23.8%) and one steroid-treated subject (2.5%)
Hypoxemia was severe (PaO2 less than 50 mm Hg) in 12 controls
(28.6%) and two (5%) of the steroid-treated subjects
Although methylprednisolone in a relatively low dose providesprotection against fat embolism and pulmonary dysfunction after
skeletal trauma, the safety of this therapy requires further
evaluation
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CONTROVERSIES
Corticosteroids as prophylaxis for FES:Several studies have demonstrated
varying results using corticosteroids inpatients identified as high-risk fordeveloping FES; while the data appearcompelling, the optimal timing, duration,
and dose of steroids are undetermined
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