(P-TA-10) Therapeutic Efficacy of Adjunct Plasma Exchange with Red Cell Exchange in Hemoglobin SC Disease Complicated by Fat Embolism Syndrome (FAS): A Case Study
University of Texas Health Science Center at Houston, Houston, Texas, USA Houston, Texas, United States
Background/Case Studies: Fat embolism is a devastating sickle cell disease (SCD) complication primarily in heterozygous patients (HbSC and HbSβ). Associated with high morbidity and mortality, the syndrome presents as respiratory failure, neurological dysfunction, and thrombocytopenia. Pathophysiology involves multiorgan dysfunction from mechanical obstruction by fat embolism and pro-inflammatory cytokine generation from circulatory fat metabolization. We aim to highlight the efficacy of adjunct therapeutic plasma exchange (TPE) with red cell exchange (RCE) in management of FAS among sickle cell patients.
Study
Design/Methods: Retrospective chart review was done of a 66-year-old male with Hgb-SC disease. He presented with left sided chest, back, bilateral lower extremities pain, and worsening respiratory status.
Results/Findings: Patient’s history was significant for 2 episodes of acute chest syndrome. On presentation he was febrile (101.7F), tachycardiac (105bpm), tachypneic (28-35pm), and with 90-92% SPO2 on 4L oxygen. Chest X-ray showed bilateral diffuse airspace opacities suggesting either disseminated pneumonia or ARDS. His labs indicated anemia (Hgb 6.4 – 7.7g/dl), thrombocytopenia (PLT: 18-36 x 103), elevated PT/PTT, INR 4.23, D-dimer >20mg/L, and fibrinogen 949mg/dL. Hgb electrophoresis revealed 51% Hgb S, and 43.6% Hgb C. Other labs included LDH 2387 U/L, ferritin 3277ng/mL, and haptoglobin 45mg/dL. Hepatic (ALT/AST: 418/252 U/L, TBil/ IndBil 2.3/1.2 mg/dL), and renal functions (BUN/Cr: 79 mg/dL/4.31 mg/dL) were also elevated. Patient underwent intubation for hypoxia and tachypnea. 2 RBC unit transfusion was done with minor respiratory function improvement and persistent multiple organ dysfunction. RBC exchange was performed with the concern of acute chest syndrome. However, no significant improvement was noted 48-hours post exchange and with failed extubating trials. Given numerous punctate foci in the brain stem, bilateral cerebellar and cerebral hemispheres, representing fat emboli, a diagnosis of FAS was considered. Hence, patient underwent a cycle of 5 therapeutic plasma exchanges (TPE), 3x daily followed by 2 every other day. He showed immediate neurologic function improvement and responded to physical stimulus. His platelet count, liver function test, and DIC panel went normal. Patient was discharged home with minimal residual neurologic symptoms. He came for follow up 2-years later with mild muscle spasm, and on continued physical therapy. His lab parameters remained normal. Conclusions: FES in SCD is a severe complication leading to systemic inflammatory response and multiorgan injury. Early recognition and combining TPE with RCE in management of these patients can be lifesaving. TPE potentially removes fat droplets and harmful circulating cytokines derived from phospholipids released from necrotic bone marrow. We recommend large, prospective studies to further validate this treatment approach.
