What manifestation indicates acute chest syndrome in an adolescent with sickle-cell anemia?

Acute chest syndrome is a severe complication of sickle cell anemia characterized by the presence of new pulmonary infiltrates on a chest X-ray and associated symptoms. Substernal retractions are a significant manifestation in this context, as they indicate increased work of breathing due to respiratory distress, which can occur from compromised lung function or airway obstruction. This physical sign reflects that the respiratory muscles are having to work harder, often due to conditions that impede airflow, such as infection or vaso-occlusive crises, common in patients with sickle cell disease.

In adolescents with sickle cell anemia, the presence of chest pain, wheezing, or fatigue and pallor can have various causes, and while they may present with these symptoms, they are not the hallmark indicators of acute chest syndrome. Substernal retractions, however, specifically indicate respiratory distress, which is often related to this life-threatening complication. Therefore, recognizing substernal retractions as a manifestation of acute chest syndrome is crucial for timely intervention and management.