Congenital Stridor

AHARSH, VIBRATING SOUND OF variable pitch, stridor implies partial airway obstruction resulting in turbulent airflow through a narrowed segment of airway.¹ Stridor is characteristically heard on inspiration, suggesting airway obstruction above the glottis in either the larynx or the pharynx.² Infants with upper-airway obstruction typically demonstrate prolonged inspiration.³ Expiratory stridor suggests lower-airway obstruction in the intrathoracic tracheobronchial tree.² Stridor may also manifest as biphasic (both inspiratory and expiratory), usually indicating midtracheal lesions.⁴