investigations

Last reviewed 08/2021

The diagnosis of pneumothorax is usually confirmed by imaging techniques

  • chest radiology:
    • presence of a white visceral pleural line separated from the parietal pleura and chest wall by a collection of gas, resulting in a loss of lung markings in this space is a hallmark of the condition
    • standard erect PA chest x-ray
      • inspiratory films are recommended for the initial diagnosis of pneumothorax
      • expiratory films are not thought to confer additional benefit in the routine assessment of pneumothorax
    • lateral x-ray
      • may provide additional information when a suspected pneumothorax is not confirmed by a PA chest film. However, they are no longer used routinely in everyday clinical practice
    • supine and lateral decubitus x-rays
      • useful for trauma patients who cannot be safely moved, less sensitive than erect PA x-rays for the diagnosis
    • chest films may need to be repeated within a short period to assess change in the size of the pneumothorax
  • ultrasound
    • specific features on ultrasound scanning are diagnostic of pneumothorax but is mainly used in the management of supine trauma patients
  • CT
    • recommended for uncertain or complex cases
    • regarded as the gold standard in the detection of small pneumothoraces and in size estimation
    • useful in differentiating a pneumothorax from large bullae (1,2)

In addition to imaging, arterial blood gases will show hypoxia

  • hypoxaemia is greater in cases of SSP
  • not required if the oxygen saturations are adequate (>92%) on breathing (1)

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