understanding pneumothorax

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Thoracic System Pathology

An open, traumatic wound leading to pneumothorax: the air can come from either an injured lung, the outside, or both. Think about how respiration occurs- the diaphragm retracts, causing negative pressure. In order to balance the pressure, the lungs would normally fill with air. However, in someone with a "sucking chest wound", that negative pressure can cause air from the outside to enter the thoracic cavity or a large amount of air to leak out of the lung.

A tension pneumo occurs when the air inside the chest cavity accumulates faster than it is removed, thus leading to lung collapse, shifting of the mediastinum towards the unaffected side, and impaired bloodflow. Theoretically, any pneumo could become a tension pneumo. Probably (and this is just my conjecture) a spontaneous pneumo is rarely going to become a tension pneumo because the injury to the lung is generally small. Of the ruptured (and non ruptured) blebs I've watched surgeons remove, many are smaller than a marble, although they may be multiple and "clustered". It's more likely that a severe injury with a sucking chest wound would accumulate air in the pleural space faster than it can be removed and cause more severe problems.

We frequently see patients for pleurodesis following spontaneous pneumo. They have all been younger than 30, male, very tall, and skinny. When a patient has a spontaneous pneumo, recurrence rate is pretty high. These patients not only get a chest tube to evacuate the pneumo, but at some point will come to the OR where the surgeon uses either a talc spray or mechanical methods that will lead to the lung adhering to the chest wall in hopes of not having it happen again.