• Clinical science



Atelectasis is a loss of lung volume that may be caused by a variety of ventilation disorders, for instance, bronchial injury or an obstructive mass such as a tumor. It may be categorized as obstructive, nonobstructive, postoperative, or rounded. Clinical features depend on the severity and extent of atelectasis, ranging from no symptoms to respiratory distress. Physical examination reveals a dull note on percussion and diminished breathing sounds over the affected area. On x-ray, the atelectatic section of the lung appears condensed and, due to decreased lung volume, may extend to the surrounding tissue. This effect can lead to an elevated diaphragm and mediastinal shift to the affected side. Treatment depends on the underlying cause. Complications of atelectasis include pneumonia or, depending on the extent of disease, respiratory failure.



Clinical features



  • Arterial blood gas analysis: hypoxemia, potentially low PaCO2, and respiratory alkalosis
  • Chest x-ray and CT: evidence of lobar collapse
    • Direct signs: displacement of fissures and homogeneous opacification of the collapsed lobe
    • Indirect signs
      • Elevation of ipsilateral diaphragm
      • Displacement of the hilum and mediastinal structures towards the affected side
      • Loss of volume in the affected side of the chest
      • Increased lucency and overinflation of the unaffected lung; silhouetting of the diaphragm or the heart border
  • Bronchoscopy (diagnostic and therapeutic): A biopsy may be performed if the etiology is uncertain despite imaging (e.g., to exclude malignancy) and mucus plugs can be removed.



The risk of atelectasis after surgery can be avoided by prescribing opioids in doses that are sufficient for pain relief, as well as encouraging the use of incentive spirometry. At the same time, opioids should be used with caution due to their suppression on coughing. Smoking should be avoided 6–8 weeks prior to surgery.




We list the most important complications. The selection is not exhaustive.

Prevention of post-operative atelectasis

  • Preoperative measures
    • Smoking cessation prior to elective surgery (6–8 weeks)
    • Physical therapy (e.g, breathing and aerobic exercises)
    • Treatment of poorly controlled asthma, symptomatic COPD, and respiratory chest infections.
  • Intraoperative ventilation with PEEP