PNEUMOTHORAX

condition in which air accumulates in the pleural sac, causing it to expand and thus compress the underlying lung, which may then collapse. (The pleural sac is a cavity formed by the two pleural membranes that line the thoracic cavity and cover the lungs.) Traumatic pneumothorax is the accumulation of air caused by penetrating wounds (knife stabbing, gunshot) or other injuries to the chest wall, after which air is sucked through the opening and into the pleural sac. Spontaneous pneumothorax is the passage of air into the pleural sac from an abnormal connection created between the pleura and the bronchial system as a result of tuberculosis or some other lung disease. The symptoms of spontaneous pneumothorax are a sharp pain in one side of the chest and shortness of breath. Artificial pneumothorax, which now is of strictly historical interest, was achieved by injecting air into the sac by means of a needle inserted into the chest wall. This procedure was used in the treatment of tuberculosis; the injected air served to compress the underlying lung and thus stop its movement, giving it time to heal free of the stress of breathing.