Imaging Acute Airway Obstruction in Infants and Children

Acute airway obstruction is much more common in infants and children than in adults because of their unique anatomic and physiologic features. Even in young patients with partial airway occlusion, symptoms can be severe and potentially life-threatening. Factors that predispose children to airway compromise include the orientation of their larynx, the narrow caliber of their trachea, and their weak intercostal muscles. Because the clinical manifestations of acute airway obstruction are often nonspecific, clinicians often rely on the findings at imaging to establish a diagnosis. Several key anatomic features of the pediatric airway make it particularly susceptible to respiratory distress, and the imaging recommendations for children suspected of having acute airway obstruction are presented. Although cross-sectional imaging may be helpful, the diagnosis can often be established by using radiographs alone. Radiographs of the chest and upper airway should be routinely acquired; however, for the child who is in severe distress, a single lateral radiographic view may be all that is necessary. The purpose of this article is to provide an imaging approach to acquired causes of acute airway obstruction in children, including (a) abnormalities affecting the upper portion of the airway, such as croup, acute epiglottitis, retropharyngeal infection, and foreign bodies, and (b) abnormalities affecting the lower portion of the airway, such as asthma, bronchiolitis, and foreign bodies. It is essential that the radiologist recognize key imaging findings and understand the pathophysiologic features of acute airway obstruction because in most cases, when the cause is identified, the condition responds well to prompt management.