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Clinical Evaluation of the Safety of High-Vacuum Chest Drainage

High-vacuum chest drainage has long been considered dangerous because of possible suction injury to the lungs. I discovered that this is a misconception caused by mixing up vacuum pressure and suction force generated by vacuum pressure.1 High vacuum pressure itself is harmless unless it generates an excessive suction force. For example, if a closed-end chest tube without any side hole is inserted into the chest cavity and connected to an extremely high vacuum pressure, nothing happens. If we puncture the tube with a fine needle, however, the air in the chest cavity is sucked out by the chest tube and the lungs come into direct contact with the chest tube. The force pulling the lungs toward the chest tube is generated by vacuum pressure inside the tube through the needle hole. This suction force is referred to as suction force per hole (SFH). The SFH is a function of the opening area (A) and vacuum pressure ( P).