Acute chest syndrome in sickle cell anemia: Diagnostic challenges and therapeutic strategies

Sickle cell disease is a genetic blood disorder caused by a mutation in the amino acid glutamic acid, which is replaced by valine in the beta chain of the hemoglobin molecule. In this context, acute chest syndrome is a serious disease with a high rate of morbidity and mortality, accounting for approximately 25% of deaths in patients with sickle cell anemia. Thus, the objective of this study is to describe the main aspects of Acute Chest Syndrome (ACS) in patients with sickle cell anemia. This is a review study of a scoping review in which data collection was carried out on the research portal of the Virtual Health Library (BVS). The databases used were: Online Medical Literature Search and Analysis System ( MEDLINE ) and Latin American and Caribbean Literature in Health Sciences (LILACS ) , where the following descriptors were used for the search: “Sickle Cell Anemia” AND“Acute Chest Syndrome”. Using the descriptors, 451 articles were found. The inclusion criteria were: articles published between 2019 and 2024, available in full and free of charge; and the exclusion criteria were repeated articles, paid articles, and methods with an emphasis on literature review. Through the established criteria, 20 studies were included in the final sample. Acute chest syndrome is characterized by fever and/or respiratory symptoms with pulmonary infiltrates, which can lead to sepsis and cause stroke in patients with sickle cell anemia. In addition, hemolysis increases during sickle cell crises, causing a faster depletion of nitric oxide, which is a potent vasodilator of metabolism and a factor for cardiopulmonary hemodynamics. In this context, ultrasound is recognized as the gold standard in the diagnosis of the syndrome, due to the absence of radiation, with high accuracy, sensitivity, and specificity. Changes in lung function in acute chest syndrome cause variations in the levels of inflammatory markers that can help to recognize the condition and treat it more effectively, such as phosphatidylserine, a specific type of phospholipid that is essential in cell membranes, serum ferritin, which increases in an attempt to compensate for the increase in hemolysis, and IL-6, which reflects the recruitment of monocytes and other innate immune cells in the lungs. In view of the intense hemolysis, red blood cell transfusions can be seen as a protective factor for acute chest syndrome and can even be considered the definitive therapy for the syndrome, as it improves the supply of oxygen to the tissues, increases the overall level of hemoglobin and reduces the fraction of sickle-shaped red blood cells. This allows the patient to have relief from respiratory symptoms more quickly. Therefore, acute chest syndrome in patients with sickle cell anemia requires appropriate interventions and should be treated as rare diseases in health units, whether in the basic health unit or in emergency care, in order to ensure adequate treatment without delays. Thus, the management that should be carried out is analgesia, hydration, antibiotic therapy, bronchodilators, ventilation, which may be invasive or non-invasive, oxygen and blood transfusion.