High risk and low prevalence diseases: Acute chest syndrome in sickle cell disease

Introduction: Acute chest syndrome (ACS) in sickle cell disease (SCD) is a serious condition that carries with it a high rate of morbidity and mortality. Objective: This review highlights the pearls and pitfalls of ACS in SCD, including diagnosis and management in the emergency department (ED) based on current evidence. Discussion: ACS is defined by respiratory symptoms and/or fever and a new radiodensity on chest imaging in a patient with SCD. There are a variety of inciting causes, including infectious and non-infectious etiologies. Although ACS is more common in those with homozygous SCD, clinicians should consider ACS in all SCD patients, as ACS is a leading cause of death in SCD. Patients typically present with or develop respiratory symptoms including fever, cough, chest pain, and shortness of breath, which can progress to respiratory failure requiring mechanical ventilation in 20% of adult patients. However, the initial presentation can vary. While the first line imaging modality is classically chest radiograph, lung ultrasound has demonstrated promise. Further imaging to include computed tomography may be necessary. Management focuses on analgesia, oxygen supplementation, incentive spirometry, bronchodilators, rehydration, antibiotics, consideration for transfusion, and specialist consultation. Empiric antibiotics that cover atypical pathogens are necessary along with measures to increase oxygen-carrying capacity in those with hypoxemia such as simple transfusion or exchange transfusion. Conclusions: An understanding of ACS can assist emergency clinicians in diagnosing and managing this potentially deadly disease.