Cerebral fat embolism syndrome is an under‐recognized yet well‐known complication of bone marrow necrosis occurring in patients with sickle cell disease. We highlight a case manifested by multisystem organ failure in an elderly patient who attained neurologic recovery with prompt initiation of hematology consultation, RBC exchange, and supportive measures.

Non-traumatic fat embolism (ntFES) is an under-recognized yet well described complication of bone marrow infarction occurring in patients with sickle cell disease with an estimated incidence of 0.3% to 37%. Presentation includes respiratory failure, neurological deficits, and petechial rash. Though scoring systems exist to aid in its diagnosis, its nonspecific manifestations require a heightened index of suspicion. Prompt recognition is vital to reduce mortality and disability. A 75 year-old female with Hemoglobin SC (HbSC) disease initially presented with bilateral thigh pain treated as a sickle cell pain crisis. She rapidly declined to multi-organ dysfunction within 36 hours of admission. Her symptoms progressed to unresponsiveness and respiratory failure requiring urgent intubation. Laboratory testing revealed precipitous drops in hemoglobin, platelets and increases in troponin and A-a gradient. Head tomography was unrevealing. She was transferred to a tertiary care facility. Brain MRI showed multiple micro hemorrhages across the neuroparenchyma. An emergent red blood cell (RBC) exchange was performed. Epileptiform activity was seen in telemetry without clinical evidence of seizures. Twenty-four hours after the exchange her GCS was 2/10T. She slowly and erratically recovered to a GCS of 10/10T in a period of fourteen days. However, she remained profoundly paretic and continued to require ventilation and assisted feeding. She was discharged to an acute rehabilitation facility. Two months after therapy her exam revealed 4+/5 strength in all extremities, fluent speech and ADL independence. She was discharged from this facility 75 days after presentation. Most cases of FES occur in young patients and are trauma related. A few cases have been described in HbSC disease. Cases presenting primarily with encephalopathy carry a worse prognosis. Several mechanical, biochemical and immunological hypotheses have been proposed. One of them suggests that an unknown trigger (virus, immunologic reaction or increased viscosity in HbSC patients due to higher hemoglobin) causes bone marrow necrosis (BMN) which in turn causes fat embolism and hypoxia. The resulting hypoxia perpetuates the cycle by increasing sickling, ultimately increasing BMN. Acute presentation with confounders such as encephalopathy, troponin elevation and cytopenia can lead to time-consuming and often unnecessary testing. Red blood cell exchange may decrease mortality from 91% to ∼30%. Clinicians must have a high index of suspicion in patients with sickle cell disease who develop acute hypoxia and encephalopathy. Hematology consultation, RBC exchange and acute rehabilitation must not be delayed in order to improve outcomes.

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