Acute chest syndrome

Did You Know?

• Acute chest syndrome is an indication for exchange transfusion.
• Bronchodilators may be useful but have not been well studied.
• Chronic complications from recurring acute chest syndrome include cor pulmonale, pulmonary hypertension, chronic sickle lung disease, and restrictive pulmonary function.

Various Etiologies

Acute chest syndrome is often precipitated by a lung infection, whose inflammation and loss of oxygen saturation promote further sickling of red cells, worsening pulmonary and systemic hypoxemia, sickling, and vaso-occlusion. Other possible causes include bone marrow fat embolism, atelectasis, pulmonary edema, or sickle cell aggregation in the intrapulmonary vasculature. A precipitous drop in hemoglobin well below the patient's baseline may help distinguish acute chest syndrome from other conditions.

Diagnosis

Diagnosis is complicated by the syndrome's similarity to pneumonia, as both can show a new lung opacification on chest x-ray. Common features include fevers, low blood oxygen levels, increased respiratory rate, chest pain, and cough. The diagnostic workup typically involves chest x-ray, complete blood count, reticulocyte count, ECG, and blood and sputum cultures; additional tests such as CT scan may be needed to exclude heart attack or other pulmonary pathology.