A patient has a pneumothorax, what kind of pressure is lost in the chest cavity?

A patient has a pneumothorax, what kind of pressure is lost in the chest cavity?

• A. Positive pressure
• B. Atmospheric pressure
• C. Intrapulmonary pressure
• D. Negative pressure

Answer: (D)

Intrapleural pressure in the pleural space is normally negative, which keeps the lung stretched and attached to the chest wall. A pneumothorax allows air to enter that space, so the intrapleural pressure becomes less negative or even positive, eliminating that suction. With the negative pressure lost, the lung collapses or partially collapses. So the pressure being lost is the negative intrapleural pressure.

Intrapleural pressure in the pleural space is normally negative, which keeps the lung stretched and attached to the chest wall. A pneumothorax allows air to enter that space, so the intrapleural pressure becomes less negative or even positive, eliminating that suction. With the negative pressure lost, the lung collapses or partially collapses. So the pressure being lost is the negative intrapleural pressure.