What is the first chamber of the chest tube collection system?

• A. Water seal chamber
• B. Drainage collection chamber
• C. Suction chamber
• D. Occlusive dressing

Answer: (B)

The first chamber is the drainage collection chamber. This compartment is the initial reservoir where fluid draining from the pleural space—such as blood or serous fluid—collects after it leaves the chest tube. It provides a place to measure and monitor the amount of drainage over time. The other chambers serve different roles: the water-seal chamber acts as a one-way valve to prevent air from moving back into the chest while allowing air from the pleural space to escape, and the suction chamber delivers negative pressure to enhance drainage. The occlusive dressing is used to seal the chest tube insertion site externally, not part of the internal drainage sequence.