Which statement accurately describes a dry suction chest drainage system?

• A. It uses a water column to seal the pleural space.
• B. It uses a built-in regulator to set suction without a water column.
• C. It cannot regulate suction.
• D. It requires connection to external power.

Answer: (B)

Dry suction chest drainage systems regulate suction with a built-in regulator and do not rely on a water column. The regulator sets and maintains a precise negative pressure, so you get a stable suction level without needing to fill or monitor a water-filled column. This is why the description of using a built-in regulator to set suction without a water column is the accurate one.

In contrast, systems that use a water column rely on fluid height to generate and regulate suction, which can fluctuate with bubble activity or fluid changes. Also, these devices can’t claim to regulate suction automatically, and they don’t require external electrical power—they typically draw energy from wall suction to operate while the internal regulator maintains the set pressure.