Acute Chest Syndrome in Sickle Cell Disease: Pathophysiology and Management

Abstract

Acute chest syndrome (ACS) is defined as the development of a new pulmonary infiltrate and respiratory symptoms in a patient with sickle cell disease (SCD). One of the most serious complications of SCD, ACS is the leading cause of mortality in patients with SCD. ACS is age dependent, with children having milder disease that often is infectious. Adults often have more severe disease, with pulmonary fat embolism secondary to preceding long bone infarction frequently as a contributing factor. Rapid diagnosis and a high index of suspicion are crucial since this syndrome may have a high mortality rate. A high white blood cell count and a falling hemoglobin tend to be associated with this illness. Patients are often febrile, but may not have positive blood or sputum cultures. Appropriate therapy includes judicious fluids, close attention to respiratory care, antibiotics, and transfusion therapy. Use of the drug, hydroxyurea, has been shown to decrease the incidence of ACS. Patients with repeated episodes are at risk for the development of chronic lung disease and pulmonary hypertension. New treatment strategies such as inhibitors of cytokines and pulmonary vasodilators such as nitric oxide may reduce the high mortality of ACS.