77 - The Lung in Sickle Cell Disease

Abstract

Pulmonary problems with sickle cell disease (SCD) cause significant morbidity and mortality, with chronic respiratory complications often beginning in childhood. Respiratory complications of SCD affect every structure of the lungs (pulmonary vascular, parenchymal, and airways alterations). Acute chest syndrome (ACS) is the leading cause of death, and recurrent ACS episodes are the major risk factor for sickle chronic lung disease. Abnormal pulmonary function is often one of the earliest indicators of lung disease. Whereas adolescents and adults with SCD tend to have restrictive lung function abnormalities, children more frequently have obstructive abnormalities. Children with SCD, as a consequence of their chronic anemia, have an elevated pulmonary capillary blood volume that significantly correlates with their increased airways obstruction. Children with SCD experience a decline in lung function, which is most rapid in younger children in whom ACS episodes are most common, highlighting the importance of identifying effective strategies to prevent and optimally treat ACS. A physician’s diagnosis of asthma has been significantly related to an increased rate of ACS, but whether anti-asthma therapy reduces ACS episodes has not been definitively evaluated. Furthermore, wheezing in SCD may be due to a number of causes, and affected children should be appropriately assessed before a diagnosis of asthma is assumed. There is increasing focus on pulmonary care of patients with SCD, and the number of studies investigating respiratory complications has markedly increased in recent years. Whether new treatment options for preventing recurrent sickle cell crises or more aggressive treatment of anemia would improve lung function and long-term outcomes merits testing.