What is the primary purpose of chest tubes in medical treatment?

The primary purpose of chest tubes in medical treatment is to re-establish negative pressure in the pleural space. When the pleural space becomes filled with air, fluid, or blood, the normal negative pressure that allows the lungs to expand properly is disrupted. This can lead to complications such as pneumothorax or pleural effusion, where the lung may collapse or be unable to expand fully.

Inserting a chest tube helps to remove excess air, fluid, or blood from this space, effectively restoring the negative pressure necessary for lung re-expansion. By doing so, the chest tube not only facilitates the lungs' ability to function normally but also helps with overall respiratory mechanics and gas exchange. This is why the answer regarding the re-establishment of negative pressure is crucial in understanding the role chest tubes play in patient care.