How does a three-chamber system differ from a single-chamber gravity drainage system?

• A. Three-chamber system uses only manual gravity drainage without suction control.
• B. Three-chamber has collection, water-seal, and suction control; single-chamber gravity relies on gravity drainage without active suction control.
• C. Single-chamber has suction control; three-chamber does not.
• D. They are identical in function.

Answer: (B)

The main idea is how suction and sealing are handled. A three-chamber chest drainage setup adds a dedicated suction-control chamber and a separate water-seal chamber, giving you active, adjustable negative pressure to aid drainage and to keep air from flowing back into the pleural space. The seven components: collection chamber to gather fluid or air, a water-seal chamber that acts as a one-way valve to prevent backflow, and a suction-control chamber that connects to wall suction to regulate how much negative pressure is transmitted to the chest.

In contrast, a single-chamber gravity drainage system relies on gravity for drainage and does not have a separate suction-control chamber. It lacks that active pressure regulation, so the drainage rate is mostly passive and depends on the height of the collection bottle and the patient’s condition. The water-seal concept can still be present, but there isn’t an adjustable suction mechanism to boost or fine-tune drainage when needed.

So, the key difference is the presence of an adjustable suction-control chamber plus the separate water-seal in the three-chamber system, enabling regulated negative pressure, whereas the gravity-based single-chamber system provides passive drainage without that suction control.