Evaluation of the upper airway.

The evaluation of infants and children with upper airway obstruction always involves a history and physical examination, which in many cases allow a diagnosis to be made. Assessment of severity and response to treatment relies on subjective parameters. Flow-volume loop analysis is a rapid, simple and effective method of evaluating patients with upper airway obstruction non-invasively. Imaging studies are complementary to endoscopy, and include plain radiography as well as computed tomography and magnetic resonance imaging, with the latter two being increasingly used in the evaluation of the paediatric airway. The ultimate diagnostic test for evaluation of upper airway obstruction, however, is flexible endoscopy.