You may identify a tension pneumothorax as follows:

For awake patients

Universal features of tension pneumothorax are chest pain and respiratory compromise [1], neither of which are discriminatory of course.

Low oxygen saturations may be an early feature; hypotension tends to be late. Both may have other causes.

Lateralising the pneumothorax may not be straight forward. Listen for decreased breath sounds on the affected side, and it may be better to listen in the axillae rather than over the anterior chest wall.

Note the classical signs of hyper-resonance and tracheal deviation are soft.

Bedside chest ultrasound is being increasingly used in the diagnosis of pneumothorax and has a high sensitivity

For ventilated patients

Fig 2: Ventilator

Early reliable signs are:

  • Decrease in oxygen saturations  – this is likely to be prompt
  • Decrease in BP
  • Tachycardia

Look, too, for raised ventilation pressure (greater than 40) and ensure that you’ve set the ventilator pressure alarm settings  appropriately (image above).

Lateralising signs are the same as for awake patients.

If your patient is not critical (we have not defined that; use common sense), then you may have time to perform an urgent bedside thoracic ultrasound scan (USS). However, this should not delay emergent treatment in a deteriorating patient. This should help you:

  • Confirm or refute the diagnosis
  • Confirm the side of pneumothorax
  • Rule in or out other diagnoses

Learning Bite

X-ray imaging is not recommended for the diagnosis of a tension pneumothorax – if there are suspicions, proceed with decompression and image afterwards.