Which of the following can cause decreased breath sounds? 1. Air ...

[burchfield96]

Which of the following can cause decreased breath sounds? 1. Air or fluid in the pleural space 2. Hyperinflation of lung tissue 3. Mucus plugging of the airways 4. Shallow or slow breathing
 
  a. 2 and 4 only
  b. 1, 2, and 3 only
  c. 1, 2, 3, and 4
  d. 2, 3, and 4 only

Question 2

Inspiratory crackles in patients without excess secretions are most commonly associated with which of the following?
 
  a. Reduced chest-wall sound transmission
  b. Airways popping open during inspiration
  c. Complete obstruction of the upper airway
  d. Mucosal edema or inflammation

[Beatricemm]

Answer to Question 1

ANS: C
Airways plugged with mucus and hyperinflated lung tissue attenuate sounds through the lungs. Air or fluid in the pleural space and obesity also reduce sound transmission through the chest wall.

Answer to Question 2

ANS: B
Crackles also may be heard in patients without excess secretions. These crackles occur when col-lapsed airways pop open during inspiration. Airway collapse or closure can occur in peripheral bronchioles or in larger, more proximal bronchi.