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