To restore the chest to its normal condition, what must be removed?

• A. Air
• B. Air and Tissue
• C. Air and Fluid
• D. Fluid and Pus

Answer: (C)

Restoring normal chest function requires clearing the pleural space of what prevents the lung from expanding. A chest tube is placed to drain contents from that space, including both air and fluid. Air in the pleural space (pneumothorax) causes lung collapse, while fluid (pleural effusion, hemothorax) compresses the lung. Removing both allows the lung to re-expand and negative intrapleural pressure to be re-established. If only air or only fluid is removed, the other still blocks full expansion. Pus can indicate infection, but the fundamental reason to drain is to eliminate both air and fluid so the chest returns to normal.