Chapter 15_ The Lung: Atelectasis

Question 1

What is an Atelectasis?

Answer 1

Atelectasis refers either to incomplete expansion of the lungs (neonatal atelectasis) or to the

• *collapse of previously inflated lung**, producing areas of relatively airless pulmonary
• *parenchyma.**

Question 2

Describe Acquired Atelectasis.

Answer 2

Acquired atelectasis, encountered principally in adults.

Divided into three:

• resorption (or obstruction),
• compression, and
• contraction atelectasis

Question 3

Answer 3

FIGURE 15-2 Various forms of acquired atelectasis. Dashed lines indicate normal lung
volume.

Question 4

Describe Resorption atelectasis.

Answer 4

Resorption atelectasis is the consequence of complete obstruction of an airway, which in time
leads to resorption of the oxygen trapped in the dependent alveoli, without impairment of blood
flow through the affected alveolar walls.

Since lung volume is diminished, the mediastinum shifts toward the atelectatic lung.

Question 5

Resorption atelectasis is caused principally by :

Answer 5

excessive secretions (e.g., mucus plugs) or exudates within smaller bronchi and is therefore most often found in:

• bronchial asthma,
• chronic bronchitis,
• bronchiectasis,
• postoperative states,
• aspiration of foreign bodies and, rarely, bronchial neoplasms.

Question 6

What is compression atelectasis?

Answer 6

Compression atelectasis results whenever the pleural
cavity is partially or completely filled by fluid exudate, tumor, blood, or air (the last-mentioned
constituting pneumothorax) or, with tension pneumothorax, when air pressure impinges on and
threatens the function of the lung and mediastinum, especially the major vessels.

With
compressive atelectasis, the mediastinum shifts away from the affected lung.

Question 7

Describe Contraction Atelectasis.

Answer 7

Contraction
atelectasis occurs when local or generalized fibrotic changes in the lung or pleura prevent full
expansion.

Question 8

Atelectasis is irreversible.

T or F

Answer 8

False

Significant atelectasis reduces oxygenation and predisposes to infection.

Because the
collapsed lung parenchyma can be re-expanded, atelectasis is a reversible disorder (except
that caused by contraction).

Question 9

All Atelectasis are irreversible except Contraction?

T or F

Answer 9

False

atelectasis is a reversible disorder (except
that caused by contraction).
Atelectasis (Collapse)