Question

A small child swallows a chicken bone. The bone perforates the wall of the esophagus in the distal third (closest to the stomach), but no other structures. Air is seen by x-ray in the mediastinum and crepitus can be felt in the neck. There is also a pneumothorax in the left pleural cavity.

How does air get into the mediastinum? How does air get into the neck? How does air get into the pleural cavity to cause a pneumothorax?

Answer 1

The mediastinum sits between the lungs. It contains the heart, thymus gland, and part of the esophagus and trachea The distal part of the oseophagus is part of mediastinum, so the bone of the chicken would have pierced the tissue layer of oseophagus causing the leak of air and getting air trapped in this area, this condition is often refered to as Pneumomediastinum

. The sources for free air in the neck are numerous, it could be form the head, by direct opening of potential fascia spaces, dissection within the fascia spaces, sinuses, etc, in this particular case it could from the mediastinum, Air released during injury seeks an escape route from the lungs so from the mediastinal area, it rises to the neck, where it becomes trapped under the skin.

Pneumothorax refers to the accumulation of air in the pleural cavity, the wound or the tissue injury in the lung acts as a flap valve, allowing air to enter the pleural space during inspiration but not allowing it to escape during expiration, as a result air accumulates in pleural cavity