Last reviewed 08/2021

A tension pneumothorax develops when there is an oblique opening into the visceral pleura which acts as a flap valve. Air enters into the pleural cavity during inspiration but cannot escape during expiration.

Pressure within the pleural cavity increases progressively leading to haemodynamic compromise (due to impaired venous return and decreased cardiac output), collapsing of the lung and shifting of the mediastinum to the opposite side.

This is a medical emergency requiring urgent decompression. Untreated, the patient may die within minutes hence a high index of suspicion is required in order to make the correct diagnosis and to manage it effectively.

Most frequent situations where tension pneumothorax arises are:

  • ventilated patients on ICU
  • trauma patients.
  • resuscitation patients (CPR).
  • lung disease, especially acute presentations of asthma and
  • chronic obstructive pulmonary disease.
  • blocked, clamped or displaced chest drains.
  • patients receiving non-invasive ventilation (NIV).
  • miscellaneous group, for example patients undergoing hyperbaric oxygen treatment (2)