Fat Embolism

Definition

 

Embolic marrow fat macroglobules damage small vessel perfusion

- leading to endothelia damage in pulmonary capillaries

- leads to respiratory failure and ARDS like picture

 

Epidemiology

 

Fat embolism

- 90% of traumas

 

Fat Embolism Syndrome

- 3 - 4 % 

- 10% mortality

 

Aetiology

 

Long bone or pelvic trauma

Femoral fracture + head injury

Nonoperative femoral treatment

Reamed femoral nails

Bilateral femoral fractures

 

Orthopaedic procedures including THA

 

Liposuction

IV lipids

 

Pathology

 

1.  Mechanical

- blockage

- likely minimal part 

 

2.  Biochemical

- damage to endothelium

- via fatty acids liberated by lipoprotein lipase

- leads to increased endothelial permeability

 

Diagnosis / Gurd's criteria 

 

One major and 4 minor criteria, plus fat microglobulinaemia must be present

 

Major

- respiratory symptoms / pulmonary oedema

- cerebral signs / altered mental status

- petechial rash (only 20 - 50%, over upper body especially axilla)

 

Minor

- PR > 110

- fever > 38.5

- retinal petechiae / fat globules

- jaundice

- elevated ESR

- renal dysfunction

- acute drop in Hb / platelets

- fat globules in urine or sputum

 

Management

 

Supportive

- maintain BP, UO

- mechanical ventilation

 

Prevention

- stabilisation of long bone fractures

- both reamed and unreamed nails cause increase fat embolism