Fat embolism syndrome

Background

-fat globules in pulmonary microcirculation -fat is prothrombotic and pro-inflammatory -commonly associated w orthopedic fractures, esp long bone fractures of lower extremities (eg. femur) -men>women, highest ages 10-40 y/o

Clinical Features

-multi-system dysfunction -classic triad: hypoxemia, neurological abnormalities and petechiae -neuro findings included: focal deficits, AMS, coma -thrombocytopenia and anemia common -can progress to DIC -Fulminant cases: RV dysfunction, biventricular failure, ARDS, shock, death -Other etiologies (uncommon): pancreatitis, sickle cell crisis, alcoholic liver ds, bone marrow harvest/transplant/liposuction

Differential Diagnosis

-pulmonary embolism -ARDS -pulmonary edema -alveolar hemorrhage -other cause of hypoxemia -other causes of shock

Workup

-clinical diagnosis, no gold standard -Gurd's Criteria (need 1 major, 4 minor) --Major: petechial rash, Resp symptoms w XR changes, CNS signs unrelated to another condition --Minor: tachycardia, pyrexia, retinal changes, renal abnormalities, thrombocytopenia, acute anemia, elevated ESR, fat globules in sputum

-Chest Xray/CT scan chest --bilateral patchy infiltrates -MRI brain: star-field pattern of diffuse, punctate, hyperintense lesions on DWI -Bronchoalveolar lavage -->30% of alveolar cells staining for fat strongly asso w diagnosis

Management

-supportive care -heparin and steroids have not shown improvement -O2, mechanical ventilation if needed -frequent neurochecks, consider ICP monitoring -vasopressors as needed -refractory hypotension/shock: consider ECMO

Disposition

-ICU

Sources

Kosova, E. et al. Fat Embolism Syndrome. Circulation. 2015; 131:317-320