What is the purpose of keeping the chest tube end in sterile water or seal if the tube becomes disconnected?

• A. To sterilize the end
• B. To measure air leak
• C. To maintain a seal and prevent air from entering the pleural space
• D. To secure the tube in place

Answer: (C)

Keeping the chest tube end in sterile water or a seal creates an underwater seal that serves as a one-way barrier. Air from the pleural space can escape through the water, but air from the atmosphere cannot flow back into the chest. This prevents atmospheric air from entering the pleural space if the tube becomes disconnected, reducing the risk of a pneumothorax or progression to a tension pneumothorax. It also maintains sterility of the exposed end until the system is reconnected.