Fat Embolism ...

Fat embolism syndrome may cause respiratory failure in trauma and orthopedic patients. It is clinically indistinguishable from ARDS.

This syndrome is most commonly associated with long bone and pelvic fractures, where fat from the bone marrow enters the circulation, causing inflammatory injury to the lung and a non cardiogenic pulmonary edema picture. The reaction may be triggered by thromboplastin with complement and coagulation system activation, and activation of leukocytes. The embolization is microscopic and difficult to diagnose; essentially a diagnosis of exclusion.

Clinical manifestations include neurologic changes, hypoxemia and, rarely, right heart failure. Skin manifestations include petechiae, found in 50% to 60% of patients.

Treatment includes routine care of patients with ARDS, with the caveat that the long bone fractures must be stabilized surgically. Steroids after the onset of the syndrome are controversial, with at least one study showing efficacy of methylprednisolone 7.5 mg/kg/6 hrs for 12 doses for prevention, but not treatment.