Chest Tube for a Collapsed Lung
Releasing Trapped Air and Blood So the Lung Can Expand
Why Does a Lung Collapse?
On television, a chest tube scene looks dramatic. A patient gasps. A sharp instrument enters the chest. Air rushes out. The patient improves. While simplified, the physiology behind that moment is very real. When air escapes from the lung and becomes trapped in the space between the lung and the chest wall, it is called a pneumothorax. Air belongs inside the lung’s air sacs. It does not belong in the pleural space, the thin potential space that normally contains only a trace amount of lubricating fluid.
Under normal conditions, the chest operates on negative intrathoracic pressure. This is a subtle vacuum effect that keeps the lungs expanded against the chest wall. When a person inhales, the diaphragm moves downward, the chest wall expands, pressure inside the chest drops, and air flows into the lungs. That pressure difference is what holds the lungs open. If air leaks into the pleural space, the vacuum is lost. Pressure builds where it should not, and the elastic lung tissue recoils inward. Instead of expanding, it collapses.
When Does It Become Dangerous?
A small pneumothorax may cause mild shortness of breath and can sometimes be observed. But if air continues to accumulate and cannot escape, pressure inside the chest rises with each breath. Eventually, that pressure can collapse the lung completely and begin pushing the mediastinum, the central structures of the chest, toward the opposite side.
When this pressure compresses the heart and large blood vessels, blood cannot return properly to the heart. Blood pressure falls. Oxygen drops. This is called a tension pneumothorax, and it is a true emergency. Trauma adds complexity. A fractured rib can puncture lung tissue. Torn vessels can spill blood into the chest, called a hemothorax. When both air and blood are present, it is a hemopneumothorax. In each case, the problem is trapped pressure. That pressure must be relieved.
What Is a Chest Tube?
A chest tube is a sterile, flexible plastic tube placed into the pleural space to evacuate air, blood, or fluid. It is not aggressive theater. It is a pressure relief system. Its purpose is to restore normal chest mechanics by allowing what should not be there to drain out.
The tube connects to a sealed drainage system that may include suction. This system acts as a one way valve. Air and fluid can leave the chest, but outside air cannot re enter. As abnormal pressure falls, the negative intrathoracic pressure is restored. The lung, which naturally wants to expand when pressure is normalized, re-inflates. The tube does not heal the injury itself. It corrects the physics so healing can occur.
Where Does It Go?
Chest tube placement requires careful attention to anatomy. It is typically inserted along the mid axillary line, between the fourth and fifth ribs. Beneath each rib runs an intercostal artery, vein, and nerve. Placement must avoid these structures. On the right side, the liver lies just below the diaphragm. On the left, the spleen sits nearby. Knowledge of anatomy is not optional.
After sterile preparation and local anesthesia, a small incision is made. Blunt dissection is used to carefully separate tissue layers until the pleural cavity is entered. A finger is often used to confirm entry into the space before the tube is advanced. Once positioned, the tube is secured with sutures and connected to the drainage system. Placement is deliberate, controlled, and often confirmed with imaging (usually X-ray).
What Are the Risks?
This is not a casual procedure. Bleeding, infection, and injury to surrounding structures are real risks. Improper placement could damage blood vessels, abdominal organs, or the lung itself. Even correct placement can be uncomfortable and requires close monitoring.
That is why timing matters. A chest tube is placed when the physiology demands it, not for spectacle. When performed for the right indication, it can reverse life threatening pressure within minutes. In emergency medicine, restoring oxygen and circulation often begins by restoring the physics of the chest.
THE BOTTOM LINE
• A chest tube removes trapped air or blood from the chest so the lung can expand
• It treats emergencies like pneumothorax, tension pneumothorax, and hemothorax
• It is powerful, precise, and used when pressure inside the chest cannot wait
By Dr. Karim Ali, Emergency Physician