单选题 A client with a pneumothorax receives a chest tube attached to a Pleur-evac. The nurse notices that the fluid of the second chamber of the Pleur-evac isn't bubbling. Which nursing assumption would be most invalid?
A. The tubing from the client to the chamber is blocked.
B. There is a leak somewhere in the tubing system.
C. The client's affected lung has reexpanded.
D. The tubing needs to be cleared of fluid.

【正确答案】 B

【答案解析】Bubbling in the second chamber of a Pleur-evac system signifies that air is moving from the collection chamber to the water seal chamber. It's normal for bubbling to occur during inspiration, but continuous bubbling signifies a leak in the closed system. Absence of bubbling in the second chamber signifies a block in the system. It can also mean that the affected lung has reexpanded.