Fat Embolism

Long bone fractures and pelvic fractures:

• 80–100% fat embolism

• Less than 1–30% FES

Male-female ratio: 4:1

Adult greatly increased over pediatric

Multiple fractures >single fractures

Pathologic fractures >traumatic fractures

Total hip, total knee replacement, intramedullary nailing:

• 27–100% fat embolism

• Unknown incidence FES

Unusual causes: Liposuction, fat injection, bone marrow harvest and/or transplantation, vertebroplasty, cardiopulmonary bypass, CPR, burns, pancreatitis, sickle cell disease, osteomyelitis, fatty liver, soft tissue injury

FES: <10% mortality

Preexisting FES: Respiratory failure/ ARDS, RV dysfunction, shock, coagulopathy, neurologic dysfunction

Intraop fat embolism: Shock, hypoxemia

Preexisting FES: Hypoxemia, reduced pulm compliance, pulm Htn, RV failure, hypotension, cardiac arrest, coagulopathy

Intraop embolism: Hypotension, RV failure, hypoxemia, paradoxical embolization, stroke, neurologic dysfunction (delirium to coma, postop)

Fat particles (globules of marrow fat) traveling into blood and lung.

Must distinguish fat embolism, from FES (triad of hypoxemia, petechiae, and neurologic abnormalities). Fat embolism is more common than FES.

FES can produce mild pulm dysfunction to severe ARDS.

Pulm Htn and acute RV failure may occur in severe cases of FES.

Typically the onset of signs and symptoms of FES happen 12–72 h following injury.

Fat embolism occurs commonly during femoral reaming and cementing in hip arthroplasty.

FES is confounded with cement reaction during arthroplasty.