THORACIC Section 2: Atelectasis Flashcards
Result of complete obstruction of an airway
No new air can enter and any air that is already there is eventually absorbed leaving a collapsed section of lung.
Obstructive (Absorptive)
Give the causes of obstructive atelectasis
Obstructing neoplasms
mucous plugging in asthmatics or critically ill patients
foreign body aspiration.
Results from direct mass effect on the lung.
Compressive (Relaxation IPassive)
Results from direct mass effect on the lung.
Compressive (Relaxation IPassive)
Causes of Compressive atelectasis
Most classically seen adjacent to a pleural effusion.
Could also be seen from adjacent compression of lung from a mass, hiatal hernia, or a large bleb — anything directly pushing on the lung.
Results from scarring/fibrosis which fails to allow the lung to collapse completely.
Fibrotic atelectasis (Cicatrization)
Most common causes of cicatrization atelectasis
Most classic is TB , but scarring from radiation, other infections, or really any other cause of fibrosis can do this.
Results from a loss of surface tension/inadequate pleural adherence of alveolar walls - from a surfactant deficiency
Adhesive atelectasis
Causes of Adhesive atelectasis
RDS (pre mature infants),
ARDS (more diffuse pattern),
in the setting of pulmonary embolism (loss of blood flow / lack of CO2 disrupts integrity of surfactant).
Direct Signs of Atelectasis
Displacement & Crowding (DireCt)
Displacement of the fissures - is considered one of the most dependable signs.
Crowding of vessels and bronchi in the atelectatic area - considered one of the earliest signs.
Indirect Signs of Atelectasis
SHADOW
Under most conditions, the word “Shadow” wouldmakeyouthink of Lamont Cranston (hypnotist and master detective)
— but in the case of Atelectasis, “Shadow” refers to the opacified (collapsed lung).
SHIFT
The shift refers to the movement of structures as they are “pulled” towards thesiteofvolumeloss. Remember,
space occupying things (tumors, pneumonia, pleural effusion, etc…) push things away. Atelectasis is a volume losing process - so it pulls (examples - pulling the right hilar point above the left, shifting the mediastinum, etc…).
What type of atelectasis favors diaphragmatic and mediastinal displacement?
Acute atelectasis
What type of atelectasis tends to favor compensatory overinflation of non-atelectatic lung?
Chronic atelectasis
shape that the minor fissure in cases of RUL collapse resulting from a central obstructing mass.
S Sign of Golden
What lobe?
Lobar atelectasis:
Classic look is increased density at the right heart border with loss of that border (shadow and silhouette).
The lateral will show anterior density over the heart (as the RML is anterior)
Right middle lobe atelectasis
Chronic collapse of the RML is classically described with Mycobacterium avum infection in an elderly women who is too proper to cough (Lady Windermere syndrome).
Right Middle Lobe Syndrome
Lobar atelectasis
Classic look is increased density at the right heart border similar to collapse of the RML.
Right lower lobe atelectasis
the mediastinal vessels are pulled to the right creating a triangle of opacity to the right of the trachea
Superior Triangle Sign
Lobar atelectasis:
Loss of visualization of the right hemidiaphraam
and right heart border
RLL + RML collapse
LUL atelectasis hints:
- non-visualization of the aortic knob.
- non specific peaking of the diaphragm from upward traction
- Luftsuchel Sign
Lobar atelectasis:
Flattened appearance of the contours o f the hilum and heart border.
LLL atelectasis
Flat Waist Sign
