Fat embolism

What is a fat embolism syndrome?

It is common for people who have trauma or surgery to the legs to suffer what is known as fat embolism. This is when fat from the bone marrow inside the leg bone escapes into the bloodstream and forms a collection of droplets called an emboli.

In rare cases, these emboli can block small blood vessels in the lungs, skin or brain. This triggers a series of events that lead to the much more serious condition of fat embolism syndrome.

Some people with fat embolism syndrome find their lungs can no longer absorb oxygen properly. When this happens, the person affected needs to be  admitted to an intensive care unit (ICU).

A small number of people who get fat embolism syndrome die from it.

What causes fat embolism syndrome?

Fat embolism syndrome usually happens in people who have had trauma (such as a break or fracture) or surgery of the pelvis or the long bones of the legs.

However, it can also occasionally happen as a result of another type of injury, illness or treatment during which fat droplets have been able to enter the bloodstream.

For example, it may happen as a result of:

• broken ribs
• severe burns
• massive injuries
• liposuction
• bone marrow biopsy
• pancreatitis
• diabetes
• high-dose steroid therapy.

What are the symptoms of fat embolism syndrome?

When someone has fat embolism syndrome, signs and symptoms usually start to show within one to three days.

Symptoms include:

• an altered mental state – that might show up as irritability, agitation, headache, confusion, seizures or a coma
• lung problems, such as rapid breathing, shortness of breath, difficulty breathing and a low oxygen level
• a rash on the skin, usually around the upper torso, and/or small pin-point blood spots in the eye.

To confirm fat embolism syndrome, doctors may do a number of tests, such as chest x-rays, blood tests and CT scans. If there are any heart-related symptoms, investigations such as an electrocardiogram (ECG) and echocardiography may also be done.

How is fat embolism syndrome treated?

There is no specific treatment for fat embolism syndrome. It will stop on its own and the body will re-absorb the fat.

The aim is to keep the person with fat embolism syndrome alive and well until the fat is re-absorbed.

Most people with fat embolism syndrome will have oxygen therapy to make sure all of the tissues of the body get enough oxygen. If the condition is severe, the person might need, mechanical ventilation in the ICU.

What happens in intensive care?

When someone is admitted to an ICU with fat embolism syndrome, they may have:

• their heart rate, blood pressure, oxygen saturation and temperature monitored and displayed on a bedside monitor
• an arterial line inserted to monitor their blood pressure and to take blood samples
• a central venous line inserted, through which they can be given fluids and medications such as sedatives (to help with sleep), analgesics (to control pain) and antibiotics (for infections)
• breathing assistance given via an oxygen mask, ventilator or endotracheal tube
• nutrition given via a nasogastric tube
• a urinary catheter inserted to drain and measure urine output
• chest x-rays and other tests done, such as blood tests, a CT scan and an ECG
• sequential compression devices applied to their legs to prevent blood clots forming
• an air mattress placed underneath them, to prevent pressure sores developing on the skin.

Most people with fat embolism syndrome recover substantially within a few weeks. For some people, minor problems last a long time.

Publication details

Version 1.1. First published 2015. Next review 2023.