What type of lung sound indicates upper airway obstruction?

Stridor is a high-pitched, wheezing sound caused by disrupted airflow in the upper airway, typically indicating an obstruction. It often occurs during inhalation and can be associated with conditions such as croup, epiglottitis, or foreign body aspiration. The presence of stridor is key in assessing respiratory distress, particularly in pediatric patients, and signifies that there is a narrowing or blockage in the airway that needs immediate attention.

In contrast, wheezes are associated with lower airway conditions, such as asthma or bronchospasm, and are usually indicative of inflammation or constriction in the bronchi. Rales, also known as crackles, are abnormal lung sounds generated by the movement of fluid in the alveoli and are typically associated with pneumonia or heart failure. Coarse crackles are more pronounced and often denote larger airways filled with fluid or mucus.

Recognizing stridor as a sign of upper airway obstruction is critical in emergency situations for prompt intervention.