Acute Hypoxemia and Coma in a Patient With Hemoglobin SC Disease

A Rare Case of Progressive Encephalopathy in a Sickle Cell Trait Patient: A Case Report

Fat embolism syndrome (FES) is one of the underdiagnosed and underrecognized complications that can happen in multiple medical and surgical conditions. FES can manifest in a broad spectrum of signs and symptoms and affect multiple organ systems in the human body. One of the most commonly involved is the central nervous system (CNS), mainly the brain, which can be involved in different ways, and the presenting symptoms can vary in type and severity. One of the most common causes of FES is trauma, mainly a long bone fracture or any orthopedic injury. However, one of the rare causes of FES is sickle cell disease (SCD) and thalassemia. Generalized and vague presenting symptoms, the rarity of FES, and the absence of well-defined diagnostic criteria make it a challenging diagnosis for healthcare practitioners. FES diagnosis is usually made after having a high index of suspicion in patients with underlying risk factors that can precipitate and contribute to the pathophysiology of FES. Moreover, the diagnosis is usually reached after excluding other more common and treatable conditions.

Pulmonary CT imaging findings in fat embolism syndrome: case series and literature review

BACKGROUND

Fat embolism syndrome (FES) is a rare life-threatening complication, which commonly affects the lung. Currently, the most widely accepted criteria for the diagnosis of FES are the Gurd and Wilson Criteria established nearly 40 years ago, but without pulmonary images involved. Our study aims to analyse the pulmonary computed tomography (CT) findings seen in FES.

CASE PRESENTATION

This report enrolled four cases of FES with lung involvement. The mainly symptoms and signs included dyspnea, disturbance of consciousness, anemia, thrombocytopenia and, most notably, ground-glass opacities, septal thickening, ill-defined centrilobular nodules, and patchy consolidation were demonstrated on bilateral lungs. Combining the clinical manifestations and laboratory tests, the diagnosis of FES was confirmed. With the treatment of steroids, anti-coagulation and supportive treatment, the four patients' symptoms were relieved, abnormalities in chest CT were absorbed significantly and the patients were finally discharged.

CONCLUSIONS

There are several common manifestations of FES in pulmonary CT images, and the lung parenchymal features give more information for the diagnosis of FES than the pulmonary vessel findings. Given the absence of a gold standard diagnostic test for FES, further investigation to explore new diagnostic criteria of FES involving pulmonary radiological features is needed in the future.

Fat Embolism Syndrome in Sickle Cell Disease

Fat embolism syndrome is a devastating complication of sickle cell disease resulting from extensive bone marrow necrosis and associated with high mortality rates, while survivors often suffer severe neurological sequelae. Despite that, the syndrome remains under-recognised and under-diagnosed. Paradoxically, it affects exclusively patients with mild forms of sickle cell disease, predominantly HbSC and HbSβ⁺. A significant number of cases occur in the context of human parvovirus B19 infection. We provide here a brief summary of the existing literature and describe our experience treating 8 patients in our institution. One patient had HbSS, 6 HbSC and 1 HbSβ⁺. All patients developed type I respiratory failure and neurological involvement either at presentation or within the first 72 h. The most striking laboratory abnormality was a 100-fold increase of the serum ferritin from baseline. Seven patients received emergency red cell exchange and 1 simple transfusion. Two patients (25%) died, 2 patients (25%) suffered severe neurological impairment and 1 (12%) mild neurological impairment on discharge, while 3 (38%) patients made a complete recovery. With long-term follow-up, 1 patient with severe neurological impairment and one patient with mild neurological impairment made dramatic improvements, making the long-term complete recovery or near complete recovery rate 63%. Immediate red cell exchange transfusion can be lifesaving and should be instituted as soon as the syndrome is suspected. However, as the outcomes remain unsatisfactory despite the increasing use of red cell exchange, we suggest additional therapeutic measures such as therapeutic plasma exchange and pre-emptive transfusion for high risk patients.