Pneumothorax vs Collapsed Lung

Key Terminology

• Collapsed Lung: Often used non-technically to refer to pneumothorax, but medically should be used for atelectasis.
• Atelectasis: Loss of aeration of the lung due to caving in of the air spaces.
  • Different from consolidation, where air spaces are filled with substances like pneumonia or pulmonary edema.
• Pneumothorax: Presence of air in the pleural space between the visceral and parietal pleura, not necessarily indicative of lung aeration state.

Main Points

• Collapsed lung (atelectasis) and pneumothorax are mutually exclusive terms.
  • A lung can collapse with or without pneumothorax.
  • Pneumothorax can occur with or without lung collapse.

Examples and Cases

• Case 1: Complete opacification of the left hemithorax with bronchial cutoff sign

  • Mucus plug causing collapse of the left lung.
  • Mediastinum shifted towards the opacity, indicating isolated lung collapse without significant pleural effusion.

• Case 2: Complete white-out with trachea shifted contralaterally

  • Indicates lung collapse along with large pleural effusion.
  • Hard to see delineation; lung likely collapsed around the hilum.

• Case 3: Pneumothorax with near complete right lung collapse

  • Visceral pleura visible; lung mostly collapsed, small part aerated.

• Case 4: Pneumothorax without significant lung collapse

  • Thin visceral pleura line visible; lung still 90% or more aerated, not called a collapsed lung.

Summary

• Collapsed Lung (Atelectasis): Two cases shown where this isn't due to a pneumothorax (mucus plug and pleural effusion).
• Pneumothorax: Two cases shown, one with a collapsed lung and one without.

Conclusion

• Important to differentiate terms accurately in medical contexts.
• Questions can be addressed in the comments.