What is the primary purpose of a chest drainage system attached to a chest tube?

What is the primary purpose of a chest drainage system attached to a chest tube?

• A. To re-establish negative pleural pressure
• B. To drain cerebrospinal fluid
• C. To monitor blood glucose
• D. To measure arterial blood gas levels

Answer: (A)

The main idea here is restoring the negative pressure in the pleural space so the lung can re-expand. A chest tube connected to a drainage system removes air or fluid from the pleural space, allowing intrapleural pressure to become negative again. The water-seal and suction components help ensure one-way flow and prevent air from re-entering, which supports the lung's expansion and improves ventilation. The other options describe activities unrelated to chest drainage—cerebrospinal fluid drainage, blood glucose monitoring, or arterial blood gas measurement.

The main idea here is restoring the negative pressure in the pleural space so the lung can re-expand. A chest tube connected to a drainage system removes air or fluid from the pleural space, allowing intrapleural pressure to become negative again. The water-seal and suction components help ensure one-way flow and prevent air from re-entering, which supports the lung's expansion and improves ventilation. The other options describe activities unrelated to chest drainage—cerebrospinal fluid drainage, blood glucose monitoring, or arterial blood gas measurement.