Respiratory System: Atelectasis

Atelectasis

Collapse or incomplete expansion of a lung or a portion of a lung, leading to decreased gas exchange and hypoxia

 

Can be caused by:

• airway obstruction
• compression of the lung
• â surfactant à difficulty expanding the lung

When the alveoli do not  have air, they collapse and shrivel up ~ natural recoil of lung tissue

Ventilation and perfusion are affected à impaired oxygenation

 

Signs and Symptoms:

• â expansion on the affected side
• â breath sounds on the affected side
• tachycardia, tachypnea, dyspnea
• hypoxia, cyanosis
• respiratory distress

Obstructive Atelectasis:

• air distal to the obstruction diffuses into the circulation and is not replaced à collapse
• severity ~ location of obstruction and extent of collapse; if the region is not reinflated quickly it will become necrotic and permanently damaged
• obstruction can be ~ tumors, mucous, aspirated object
• S/S: trachea/mediastinum shifts toward affected side and unaffected lung overinflates

Compression Atelectasis:

• an external mass e.g. tumor puts pressure on the lung, preventing air from reaching that region
• air or fluid in the pleural cavity can also compress the lung and separate the pleura à inability of the lung to expand
• S/S: trachea/mediastinum shifts toward the unaffected side; fever, infection