Registered Nurse (RN) Respiratory Practice Exam

The absence of fluctuation of water in the water seal chamber of a chest tube system typically indicates that there may be a problem that needs to be investigated. One key reason for this finding is that the lung may have re-expanded, which means that the pleural space has filled sufficiently with air or fluid, leading to stabilization of pressure and consequently, no further fluctuation in the chamber. This can be a very positive sign, as it suggests that the therapeutic goal of the chest tube (i.e., allowing the lung to re-expand) may have been achieved.

Additionally, a kink in the tubing can obstruct the normal flow of fluid and air, which would also prevent fluctuation. This situation would require prompt assessment and potential intervention to ensure proper function of the chest tube system.

In contrast, it is not typically expected for there to be no fluctuation if the tube is functioning properly and the lung has not re-expanded. While a system malfunction (which could cause this finding) is possible, it is generally less common than the potential for lung re-expansion or issues with the tubing. An air leak would typically present with continuous bubbling rather than cessation of fluctuation, indicating that option aligns less with the presented scenario.