What is the difference between placing a chest tube (chest drainage tube) to water seal versus clamping it?

From the Guidelines

Water seal is the preferred method over clamping for managing chest tubes, as it allows air to exit the pleural space while preventing air from entering, thereby facilitating lung re-expansion and monitoring for air leaks. This approach is supported by guidelines that emphasize the importance of avoiding clamping in most situations due to the risk of tension pneumothorax, a potentially life-threatening condition, as noted in the BTS guidelines for the management of pleural infection in children 1. Clamping a chest tube should only be considered in specific circumstances, such as during a trial clamp to check for resolution of an air leak prior to removal, or briefly during transport or when changing drainage systems. It is crucial to immediately unclamp the tube if the patient develops symptoms such as shortness of breath, chest pain, or oxygen desaturation during a trial clamp. The decision between water seal and clamping should be based on the clinical situation, the reason for chest tube placement, and the presence or absence of an air leak, with water seal being the safer option as it maintains negative pressure for proper lung expansion 1. Key considerations include:

• The risk of converting simple pneumothoraces into life-threatening tension pneumothoraces by clamping a bubbling chest drain 1.
• The importance of keeping the underwater seal bottle below the level of the patient’s chest at all times to ensure proper drainage and prevent complications 1.
• The need for a unidirectional flow drainage system, such as an underwater seal bottle, to allow air or fluid to escape from the chest while preventing atmospheric air from entering 1.

From the Research

Chest Tube Management

• The decision to use a chest tube to water seal or clamping depends on various factors, including the patient's condition and the underlying cause of the pneumothorax or pleural effusion 2, 3.
• A drain-clamping test before tube withdrawal is generally not advocated, as it may not accurately predict the risk of complications such as pneumothorax or air leak 2.
• However, a study found that clamping trials prior to thoracostomy tube removal were associated with fewer pleural drainage procedures and no increased risk of tension pneumothorax 4.

Air Leaks and Pleural Space Effects

• Active air leaks can be distinguished from pleural space effects using a digital chest drain system that provides continuous air flow and pleural pressure checks 5.
• Pleural space effects are characterized by a high differential pleural pressure, but mainly due to a lower mean inspiratory pressure, and are often related to surgical pleurodesis procedures or wide lung resections 5.
• Air leaks can be treated with various techniques, including pneumoperitoneum and autologous blood patch, which have been shown to be effective in obliterating pleural space and stopping air leaks 6.

Chest Tube Removal

• The optimal timing for tube removal is still a matter of controversy, but the use of digital drainage systems can facilitate informed and prudent decision-making 2.
• A study found that clamping trials prior to thoracostomy tube removal were safe and associated with less likelihood of a subsequent pleural drainage procedure 4.
• Chest tube removal should be guided by clinical judgment and careful monitoring of the patient's condition, including the presence of air leaks or pleural space effects 3, 5.