Atelectasis (collapse)

1. ATELECTASIS
(COLLAPSE)
RESPIRATORY SYSTEM

2. ATELECTASIS
• Defined as the
– “Collapse of pulmonary parenchyma”
– Loss of lung volume
• Caused by inadequate expansion of airspaces.
• Results in shunting of inadequately oxygenated
blood from pulmonary arteries into veins
• Giving rise to a ventilation-perfusion imbalance
and hypoxia.

3. ATELECTASIS
• Could be due to
– Incomplete expansion of a lung or part of a lung
in the newborn
• Primary atelectasis OR Neonatal atelectasis
– The collapse of previously inflated lung
• Secondary atelectasis OR Acquired
atelectasis

4. ATELECTASIS
Secondary atelectasis / Acquired atelectasis
According to the underlying mechanism
Three forms
1. Resorption Atelectasis
2. Compression Atelectasis
3. Contraction Atelectasis

5. ATELECTASIS
• Resorption Atelectasis

6. RESORPTION ATELECTASIS
• Due to obstruction that prevents air from
reaching distal airways.
• Air already present gradually absorbed-
alveolar collapse follows.
• Depending on the level of obstruction,
–an entire lung,
–a complete lobe,
–or one or more segments may be involved.

7. RESORPTION ATELECTASIS
• Common cause; obstruction of a
bronchus by a mucous or mucopurulent
plug in;
–Postoperative states
–Bronchial asthma
–Bronchiectasis
–Chronic bronchitis
–Or the aspiration of foreign bodies,
particularly in children.

8. COMPRESSION ATELECTASIS

9. COMPRESSION ATELECTASIS; Also c/a
passive or relaxation atelectasis
Pleural effusions:
–congestive heart failure (CHF), neoplastic
effusions, tuberculosis
• Basal atelectasis; resulting from the
elevated position of the diaphragm in;
• bedridden patients, patients with ascites,
and patients during and after surgery.

10. CONTRACTION ATELECTASIS

11. CONTRACTION ATELECTASIS
–Local or generalized fibrotic
changes in the lung or pleura may
prevent full expansion

12. ATELECTASIS
• Atelectasis (except that caused by
contraction)
–is potentially reversible due to collapse
lung parenchyma can be re-expanded
–and should be treated promptly to prevent
hypoxemia and superimposed infection of
the collapsed lung.

13. Pulmonary Edema

14. Left Heart Failure and
Pulmonary Edema
• LVF occurs when the left ventricle fails to function as
an effective forward pump, causing a back-pressure
of blood into the pulmonary circulation
• May be caused by a variety of forms of heart disease
including ischemic, valvular, and hypertensive heart
disease
• Untreated, significant LVF culminates in pulmonary
edema

15. Left Heart Failure and
Pulmonary Edema
• Signs and symptoms
– Severe respiratory distress
– Severe apprehension, agitation, confusion
– Cyanosis (if severe)
– Diaphoresis
– Adventitious lung sounds
– JVD
– Abnormal vital signs

16. Left Heart Failure and
Pulmonary Edema
• Signs and symptoms
– Severe respiratory distress
– Severe apprehension, agitation, confusion
– Cyanosis (if severe)
– Diaphoresis
– Adventitious lung sounds
– JVD
– Abnormal vital signs

17. Acute Pulmonary Edema
• May be CARDIAC or NON-CARDIAC in origin.
• Results from conditions such as:
– Increased pulmonary capillary pressure
– Increased pulmonary capillary permeability
– Decreased oncotic pressure
– Lymphatic insufficiency
– mixed or unknown mechanisms