A chest tube (thoracostomy tube) is a flexible, hollow device inserted through the chest wall into the pleural space (the area between the lung and the inner chest wall). Its function is to create a one-way drainage system to remove accumulated air, fluid, or blood. This evacuation re-establishes negative pressure within the chest cavity, allowing a collapsed or compressed lung to fully re-expand. The tube connects to a closed chest drainage system (CDS) that maintains this pressure gradient and uses a water seal to prevent backflow.
Managing the Chest Drainage System During Movement
Routine clamping of a chest tube for transport is not recommended. When moving a patient, the chest tube system must remain intact, and the drainage unit must always stay below the level of the patient’s chest. This dependent position uses gravity to ensure fluid drains away from the lung and maintains the water seal.
During transport, if the system is connected to wall suction, it is disconnected and placed on a water seal. The water seal allows air and fluid to exit the chest cavity but prevents re-entry. The patient’s breathing movements are often enough to push out residual air or fluid through this seal.
If the patient has a continuous air leak and cannot tolerate being off suction, a portable suction device may be used during movement. All connections must be checked and secured to prevent accidental disconnection. The drainage unit should be secured upright to a transport cart or bed frame to avoid tipping and compromising the water seal.
Risks Associated with Routine Chest Tube Clamping
Routine clamping of a chest tube is avoided because it creates a sealed, closed system that poses a significant physiological risk. If the lung is still leaking air or fluid into the pleural space, clamping prevents this material from escaping. The trapped air or fluid then builds up pressure within the chest cavity.
This rapid pressure buildup can lead to the life-threatening condition known as tension pneumothorax or tension hydrothorax. As pressure increases, it pushes chest structures—including the heart, major blood vessels, and the trachea—away from the affected side. This displacement is called a mediastinal shift.
The shift causes kinking of large veins, such as the vena cava, severely compromising blood return to the heart. The resulting drop in cardiac output and systemic blood pressure can lead to circulatory collapse and death if the pressure is not immediately relieved. Therefore, occluding the tube for a non-emergent reason like transport eliminates the safety valve and can quickly cause a catastrophic medical emergency.
Specific Situations Requiring Temporary Clamping
Despite the dangers, a chest tube may be temporarily clamped in a few specific, brief instances under strict medical supervision. One reason is to momentarily check for the location of a persistent air leak. The tube is clamped for a few seconds at various points along the tubing to isolate whether the leak originates from the patient, a connection, or the drainage unit.
Temporary clamping is necessary when the chest drainage unit needs to be changed, such as when the collection chamber is full or damaged. The tube is clamped only for the short time required to quickly disconnect the old unit and securely connect the new, sterile one. Clamping may also be performed as part of a physician-ordered trial period before tube removal. This trial involves clamping the tube for a specific duration (often four to six hours) to assess if the patient’s lung remains fully expanded without active drainage. This procedure is done only after an air leak has resolved to confirm the patient can tolerate removal. Any temporary clamping must use rubber-tipped clamps and be immediately reversed if the patient shows signs of respiratory distress.
Emergency Management of System Disconnection or Damage
If the chest tube accidentally disconnects from the drainage system, immediate action is required to prevent air from rushing into the pleural space. If the tube end is uncontaminated, the system should be reconnected immediately after cleaning the ends with an antiseptic wipe. If the tube end is contaminated or connection is delayed, the priority is to create a temporary water seal.
To establish this seal, the end of the chest tube should be quickly submerged about one to two inches below the surface of a container of sterile water or saline, which should always be kept at the bedside. This maneuver allows air to escape from the chest but prevents outside air from being sucked back in, effectively mimicking the safety function of the drainage unit’s water seal chamber. The tube must remain submerged until a new, sterile drainage unit is attached.
If the chest tube accidentally comes completely out, immediately cover the insertion site with a gloved hand. Then, apply a sterile occlusive dressing, such as petroleum gauze. This dressing must be taped on three sides, leaving one side untaped to allow any trapped air to escape from the chest cavity. This three-sided dressing prevents the development of a tension pneumothorax while medical assistance is secured.