When to apply water seal to a chest tube (Chest Tube)

From the Guidelines

A chest tube should be placed on water seal when the patient's lung has re-expanded, air leak has resolved, and drainage has decreased, as indicated by the most recent and highest quality study 1.

Key Considerations

• The decision to apply water seal to a chest tube depends on the patient's clinical circumstances, including the resolution of air leaks and the re-expansion of the lung.
• According to the BTS guidelines for the management of spontaneous pneumothorax 1, suction should not be applied directly after tube insertion, but can be added after 48 hours for persistent air leak or failure of a pneumothorax to re-expand.
• High volume, low pressure (–10 to –20 cm H2O) suction systems are recommended, and patients requiring suction should only be managed on lung units where there is specialist medical and nursing experience.

Transitioning to Water Seal

• To transition to water seal, disconnect the suction tubing from the drainage system while keeping the chest tube connected to the water seal chamber.
• The water seal chamber should remain intact with the water level at the recommended mark (usually 2 cm).
• Monitor the patient closely for 24 hours after transitioning to water seal, watching for signs of pneumothorax recurrence such as increased shortness of breath, chest pain, decreased oxygen saturation, or bubbling in the water seal chamber.

Removing the Chest Tube

• If the patient remains stable without evidence of air leak or re-accumulation of fluid on chest X-ray during this observation period, the chest tube can be removed.
• Water seal serves as an intermediate step between active suction and tube removal, allowing clinicians to ensure the underlying lung problem has resolved before completely removing the chest drainage system, as supported by the American College of Chest Physicians Delphi consensus statement 1 and the BTS guidelines 1.

From the Research

Chest Tube Management

• The application of water seal to a chest tube is a topic of interest in the medical field, with various studies investigating its efficacy and safety 2, 3, 4, 5, 6.
• According to a study published in 2017, changing chest tubes from wall suction to water seal after 12 hours of wall suction is a safe alternative to using wall suctioning until removal of the tubes 2.
• Another study from 2005 found that keeping chest tubes on water seal is safe for most patients with an air leak and a pneumothorax, but if the leak or pneumothorax is large, then subcutaneous emphysema or an expanding symptomatic pneumothorax is more likely 3.

Air Leaks and Water Seal

• Water seal is superior to wall suction for stopping air leaks after pulmonary resection, with most patients being able to have their chest tubes removed by postoperative day 3 5.
• A prospective randomized trial published in 2001 found that placing chest tubes on water seal is superior to wall suction for stopping air leaks after pulmonary resection, but water seal does not stop expiratory leaks that are 4/7 or greater 6.
• The use of water seal for air leaks is also supported by a study published in 2005, which found that water seal is the best setting for chest tubes and that a pneumothorax is not a contraindication to leaving tubes on seal 4.

Clinical Considerations

• The decision to apply water seal to a chest tube should be based on individual patient factors, such as the size of the air leak and the presence of a pneumothorax 3, 4, 6.
• Patients with large air leaks or pneumothoraces may require suction instead of water seal to prevent complications such as subcutaneous emphysema or an expanding symptomatic pneumothorax 3, 4, 6.