1-13. TENSION PNEUMOTHORAX
Tension pneumothorax, a complication of hemothorax and pneumothorax, is a
type of pneumothorax in which the intra-pleural pressure is greater than the
atmospheric pressure. A leak in the lung has occurred, and that leak has failed to seal
when the lung collapsed. With every breath the casualty takes, air continuously leaks
out of the lung into the chest cavity. The lung collapses more with every breath until
finally the lung is a small ball, perhaps two or three inches in diameter. If this condition
is not corrected, it will be fatal.
Figure 1-4. Tension pneumothorax.
a. Characteristics of Tension Pneumothorax.
(1) The margins or edges of the tear in the pleura are positioned to form a
one-way valve. This valve permits air to enter the pleural sac during inspiration
(breathing in) but prevents air from escaping during expiration (breathing out) so that
each excursion (breath) tends to increase the pressure in the chest. This causes the
other lung and the heart to be compressed.
Additionally, the heart and mediastinum are pushed away from the
(3) Ventilation (air in lungs is exchanged with atmospheric air) and
circulation are impaired.