Atelectasis:  Is an incomplete expansion of lobules (clusters of alveoli) or lung segments may result in partial or complete lung collapse.  The collapsed tissue, unable to perform gas exchange, allows unoxygenated blood to pass through it unchanged, producing hypoxemia (deficient oxygenation of the blood).  Atelectasis can be present at birth (incomplete expansion of the lungs), or during adulthood (from a  collapsed lung).  It may be chronic or acute.  It occurs to some degree in many patients undergoing upper abdominal or thoracic surgery.  Prognosis depends on prompt removal of any airway obstruction, relief of hypoxia, and reexpansion of the collapsed lobule(s) or lung(s).

Cause:  Atelectasis may be the result from:
Bronchial occlusion by mucus plugs (common problem  with  -Chronic obstructive pulmonary disease patient)
Cystic fibrosis
Heavy smoking
Occlusion by foreign bodies 
Bronchogenic carcinoma
Inflammatory lung disease
Idiopathic respiratory distress syndrome of the newborn (hyaline membrane disease)
Oxygen toxicity
Pulmonary edema
Prolong immobility
CNS depression such as ; drug overdose
Any condition that inhibits full lung expansion or makes deep breathing painful, such as; rib fractures, obesity, an abdominal surgical incisions


Symptoms varies with the degree of hypoxia

Dyspnea (labored or difficulty breathing), may be mild and subside without treatment if atelectasis involves only a small area of the lung. Severe if massive collapse occurs




Decreased breath sounds

Dull sound on percussion if a large portion of the lung is collapsed

Peripheral circulatory collapse


Substernal or intercostal retraction

Compensatory hyperinflation of unaffected areas of the lung

Mediastinal shift to the affected side


Incentive spirometry

Chest percussion

Postural drainage

Frequent coughing and deep-breathing exercise

If these measures fail, bronchoscopy may help remove secretions

Humidity and bronchodilators can improve mucociliary clearance and dilate airways and are sometimes used with a nebulizer

Atelectasis secondary to an obstructing neoplasm may require surgery or radiation therapy.

Postoperative thoracic or abdominal surgery patients require analgesics to facilitate deep breathing, which minimizes the risk of atelectasis

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