Acute chest syndrome in sickle cell disease: Pathophysiology and management

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 cau se of mortality in patients with SCD. ACS is age dependent, with children h aving milder disease that often is infectious. Adults often have more sever e disease, with pulmonary fat embolism secondary to preceding long bone inf arction frequently as a contributing factor. Rapid diagnosis and a high ind ex of suspicion are crucial since this syndrome may have a high mortality r ate. A high white blood cell count and a falling hemoglobin tend to be asso ciated with this illness. Patients are often febrile, bur may not have posi tive blood or sputum cultures. Appropriate therapy includes judicious fluid s, close attention to respiratory care, antibiotics, and transfusion therap y. Use of the drug, hydroxyurea, has been shown to decrease the incidence o f ACS. Patients with repeated episodes are at risk for the development of c hronic lung disease and pulmonary hypertension. New treatment strategies su ch as inhibitors of cytokines and pulmonary vasodilators such as nitric oxi de may reduce the high mortality of ACS.