Fat embolism syndrome

What it is

Fat embolism, written FES on the page, is rare and more in young men, but there is an increasing number in Oman due to MVAs. It is lethal in up to 15 per cent. It presents 12 hours to 3 days.

Causes and risk

Long bone fractures, and the femur shaft in particular; hip and knee arthroplasty; and other causes that are medical, such as SCD, or iatrogenic.

How it comes about

Two mechanisms are given. Mechanical: fat microglobules pass to the venous system, to the IVC, to the rt atrium, to the RT vent, and into the pulm. capillaries network, where they are trapped and cause mechanical blockage — but they have to block more than 80 per cent, which is not the same as VTE, where it is large in size. Biochemical: microglobules deposited in the pulm. capillaries stimulate an inflammatory response.

The types are subclinical, subacute, and fulminant, the last being rare.