Marcelo Figueroa Casas 

The pleural cavity is a virtual space; When air accumulates inside it, pneumothoracic syndrome develops. Air enters the pleura spontaneously, or after a diagnostic or therapeutic maneuver, or by trauma or during birth.


Under normal conditions the pressure in the pleural space is lower than atmospheric as a consequence of the forces of elastic recoil and the thoracic wall. When air enters the cavity, the lung collapses and a pneumothorax occurs. Can be:

Spontaneous is the most common and is caused by the following pathologies:

Subpleural bubbles. The tension within the lungs is greatest at the apex, so that the dormancy of bubbles in that area predisposes them to rupture. This type of pneumothorax is the most frequent, and predominates in males, between 20 and 30 years of age.

Emphysema. This disease is the second leading cause of spontaneous pneumothorax. Localized and diffuse bullous emphysema can cause it, although the former is the most common. It prevails in men over 40 years old.

Exceptionally, a pneumothorax occurs in tuberculosis, bronchial asthma, honeycomb lung, pulmonary infarction, congenital cysts and pneumoconiosis.

Traumatic . Most are caused by car accidents, but they can also result from shock waves, falls from a certain height, direct blow to the chest, injuries with sharp objects.

Other causes include iatrogenic trauma such as subclavian puncture, external cardiac massage, thoracentesis, improper removal of a drainage tube, and mechanical ventilation.

Of the newborn . It is observed as a complication of hyaline membrane disease, inhalation of amniotic fluid, bronchopulmonary malformation and persistent pulmonary dysfunction in premature infants.

Diagnostic and therapeutic . It is not currently used in practice.

Symptoms and signs

Pain is a characteristic symptom. It is located in the infected hemithorax, although it is sometimes referred to the abdomen or to the other hemithorax. It is generally severe and is exacerbated by coughing and breathing; however, it is missing in 15% of all cases.

Dyspnea is the symptom that most often follows pain. It is related to the volume of the pneumothorax, the speed of its production and the functional capacity of the lung parenchyma. It is not found in 25% of cases.

In 15% of cases there is a dry cough.

Cyanosis, lipothymia, and hyperthermia are occasionally seen, and there is often immobility of the affected hemithorax. On palpation, there is a decrease in vocal vibrations and less excursion of the bases. Percussion shows hypersonousness or bloat, while auscultation reveals decreased or abolished respiratory sound. In special circumstances a murmur is heard.

Study methodology

Chest radiology . In frontal films, the most frequent signs are the following: hyperclarity, absence of a bronchovascular pattern, lung collapse, visualization of the visceral pleura, and occasionally small volume effusions. In turn, X-rays on forced inspiration and expiration are useful for diagnosing small pneumothoraces.


Hypertensive pneumothorax . Occasionally the communication that is established between the lung and the pleura acts as a valve allowing the entry of air during inspiration and preventing the exit during expiration. The pressure in the pleural cavity exceeds the atmospheric one causing mediastinal displacement and interfering with thoracic venous return. The clinical picture is manifested by increasing diasnea, tachycardia, cyanosis, and collapse if the pleural cavity is not drained. The chest radiograph shows signs of pneumothorax with mediastinal deviation towards the healthy side.

Total pneumothorax . It is one in which the lung collapse is not blocked by adhesions between both pleural sheets.

Partial pneumothorax . There are flanges between the visceral and parietal pleura that prevent total lung collapse.

Bilateral pneumothorax . It alternates when the posterior pneumothorax occurs after the anterior one disappears. It is simultaneous when both pleural chambers coexist at some point in evolution, although they do not occur at the same time.