What is a tension pneumothorax?
A tension pneumothorax is a special form of pneumothorax and is a life-threatening injury to the lung. In contrast to a collapsed lung (pneumothorax), a tension pneumothorax also involves a kind of valve mechanism in which more and more air accumulates in the thorax, which cannot be breathed out. This leads to an increasing pressure increase within the thorax and a displacement of the mediastinum (center of the thorax, which mainly contains the heart and its inflowing and outflowing blood vessels), endangering the cardiovascular system. The most frequent causes of a tension pneumothorax are traumatic influences, such as traffic accidents.
Causes
The causes of a tension pneumothorax are the same as those of a pneumothorax. The reason is that, due to unfortunate circumstances, any pneumothorax can develop into a tension pneumothorax. The lungs are each enclosed by a thin skin, the pleura visceralis.
Together with the pleura (pleura parietalis), which surrounds the ribs, they form the so-called “pleural gap”, which contains a small amount of fluid and is under pressure. You can imagine it like two panes of glass which are wet and stick together. If air enters the gap for certain reasons, the negative pressure disappears and the respective lung, which is only kept open by the negative pressure, collapses.
This event is called pneumothorax. In a tension pneumothorax, air enters the pleural gap with each inhalation. When breathing out, however, this air cannot escape again due to a kind of valve mechanism, whereupon the air accumulates.
The reason for this is that the entry point has been displaced, for example by lung tissue. The main causes of a pneumothorax and thus also of a tension pneumothorax are traumatic events such as stab or gunshot injuries, broken ribs, contusions and excess pressure in the lungs, for example due to overpressure ventilation or during diving. A spontaneous pneumothorax, for example when lifting heavy objects, is also possible. In addition, some medical interventions can result in an injury to the pleural gap and thus in a pneumothorax caused by the doctor.
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