How do chest tubes (thoracostomy tubes) function?

From the Guidelines

Chest tubes function by creating a one-way drainage system that maintains negative pressure in the pleural cavity, allowing for the removal of air, blood, or fluid from the pleural space surrounding the lungs, and enabling the lungs to fully expand. They work by connecting the pleural space to a collection system that prevents backflow using either a water seal or one-way valve mechanism 1. When inserted through the chest wall, the tube is typically placed in the upper chest for air removal (pneumothorax) and in the lower chest for fluid drainage (hemothorax or pleural effusion) 1. The drainage system usually consists of chambers that collect fluid, maintain the water seal, and regulate suction pressure (typically -10 to -20 cm H2O).

Key considerations for chest tube management include:

• Maintenance of patency to prevent complications associated with retained blood, with techniques such as manual "milking" or "stripping" of the tubes, or the use of technologies for active chest tube clearance 1
• Pain management during placement, typically involving local anesthesia (1-2% lidocaine) and sometimes conscious sedation
• Regular assessment of tube function, drainage characteristics, and patient symptoms to prevent complications such as infection, tube dislodgement, or blockage
• The use of small (10-14 F) chest tube systems initially, with the option to replace with a larger tube if necessary, and the consideration of catheter over guidewire systems (Seldinger technique) for initial use 1

Overall, the effective management of chest tubes is critical to preventing complications and improving patient outcomes, and should be guided by evidence-based best practices and regular assessment of tube function and patient symptoms 1.

From the Research

Function of Chest Tubes

Chest tubes, also known as thoracostomy tubes, are medical devices used to drain accumulated air or fluid from the pleural cavity 2, 3, 4, 5, 6. The primary function of chest tubes is to:

• Evacuate abnormal fluid and air from the pleural space
• Remove air in the case of pneumothorax
• Drain fluid such as pleural effusion, blood, chyle, or pus

Types of Chest Tubes

There are different types of chest tubes available, including:

• Small-bore chest tubes (≤14F) recommended for spontaneous pneumothorax and pleural effusions 2
• Large-bore chest tubes useful for very large air leaks and post-ineffective trial with small-bore drains 2
• Indwelling pleural catheters (IPC) for malignant pleural effusions 2

Chest Tube Insertion and Management

Chest tube insertion should be guided by imaging, such as bedside ultrasonography or computed tomography 2, 5. The insertion technique may involve blunt dissection or the Seldinger technique 2. All chest tubes are connected to a drainage system device, which may include:

• Flutter valve
• Underwater seal
• Electronic systems
• Vacuum bottles 2, 4
• The drainage system allows for one-way movement of air and liquid from the pleural cavity 4

Complications and Care

Common complications of chest tubes include pain, drain blockage, and accidental dislodgment 2. More serious complications may include organ injury, hemothorax, infections, and re-expansion pulmonary edema 2. Proper care and management of chest tubes are essential to prevent complications and ensure effective drainage 4, 5.