Atelectasis

Question 1

Atelectasis?

Answer 1

Localized structural collapse of part of the lung -> impedes expansion

Question 2

What happens if there is no lung expansion?

Answer 2

Air cannot enter the lungs and no gas exchange occurs

Question 3

Name the 3 types of atelectasis.

Answer 3

1. Obstructive/Resorptive/Absorptive Atelectasis
2. Compression atelectasis
3. Contraction atelectasis

Question 4

Obstructive/Resorptive Atelectasis?

Answer 4

Eg. Mucus causing an obstruction for air entry/exit -> air is trapped within the alveoli -> air is absorbed into the capillaries causing a local collapse

Question 5

Compression atelectasis?

Answer 5

Eg. Tumor applies pressure against alveoli and prevents expansion -> external pressure pushes air out of the alveoli -> local collapse

Question 6

Contraction atelectasis?

Answer 6

respiratory system damaged and during healing fibrotic change occurs that decreases the ability of the lung to expand and limits lung volume

Question 7

Which type of atelectasis is due to scar tissue?

Answer 7

Contraction atelectasis

Question 8

Manifestations of atelectasis.

Answer 8

• minor may be asymptomatic
• dyspnea
• tachypnea (compensatory) -> increased rests to increase the air in the lungs
• decreased chest expansion -> seen on Px when told to breathe deeply (may be unilateral/unequal expansion, decreased on affected side)
• tracheal shift (seen on X-ray)
• decreased gas exchange -> hypoxemia & hypoxia -> tachycardia (compensatory)

Question 9

Why does a tracheal shift occur in atelectasis?

Answer 9

Trachea shifts because the greater expansion of the unaffected lung applies one-sided pressure to the trachea, causing it to move towards the affected side

Question 10

Diagnostics of Atelectasis

Answer 10

• Px (resp/cardiac)
• Chest xray (asap) [initial detect of atelectasis]
• CT scan [more precise for location and extent of atelectasis]
• Scope airway with bronchoscope (most invasive; can visualize obstruction)

Question 11

Treatment for atelectasis.

Answer 11

• depends on the cause (fix obstruction or compression)

- respiratory support for the time being

Question 12

Is atelectasis reversible?

Answer 12

Yes, as long as surfactant remains in between layers of lung tissue

Question 13

Surfactant?

Answer 13

Surfactant is secreted by T2 alveolar cells into the alveolar space to decrease surface tension within the alveoli