RT Book, Section A1 Mapelli, Elisa A1 Sabhaney, Vikram A2 Tintinalli, Judith E. A2 Stapczynski, J. Stephan A2 Ma, O. John A2 Yealy, Donald M. A2 Meckler, Garth D. A2 Cline, David M. SR Print(0) ID 1121496846 T1 Stridor and Drooling in Infants and Children T2 Tintinalli’s Emergency Medicine: A Comprehensive Study Guide, 8e YR 2016 FD 2016 PB McGraw-Hill Education PP New York, NY SN 9780071794763 LK accessmedicine.mhmedical.com/content.aspx?aid=1121496846 RD 2024/03/29 AB Stridor is a high-pitched, harsh sound produced by turbulent airflow through a partially obstructed airway. Both inspiratory and expiratory stridor are associated with airway obstruction. As air is forced through a narrow tube, it undergoes a decrease in pressure (the Venturi effect). The decrease in lateral pressure causes the airway walls to collapse and vibrate, generating stridor. Airway resistance is inversely proportional to the fourth power of the airway radius. This translates into a 16-fold increase in resistance when the radius is reduced by half. Even 1 mm of edema in the normal pediatric subglottis reduces its cross-sectional area by >50%. A small amount of inflammation can result in significant airway obstruction in children.