Which finding indicates air is trapped in the lower airways?

• A. Rales
• B. Pleural rub
• C. Wheezes
• D. Rhonchi

Answer: (C)

Air is trapped in the lower airways when the small airways (bronchioles) are narrowed or blocked, so air must squeeze through tight passages as it moves. That turbulent flow through constricted bronchioles creates a high-pitched, musical sound called a wheeze, which is most noticeable during expiration when the airways are smallest. This distinguishes it from other breath sounds: crackles (rales) come from popping open of fluid-filled or collapsed small airways, rhonchi are coarse, rattling sounds from secretions in larger airways, and a pleural rub is a grating sound from irritated pleural surfaces rubbing together. So the presence of a wheeze is the finding that indicates air is trapped in the lower airways.