Which sign indicates that a client’s chest drainage tube is functioning correctly?

Fluid level fluctuations with breathing indicate that a client's chest drainage tube is functioning correctly because this demonstrates the presence of normal respiratory mechanics. When the patient breathes in and out, the changes in intrathoracic pressure cause tidal fluctuations in the water seal or manometer, reflecting the patient's respiratory effort. This movement is expected as it confirms that the drainage system is effectively allowing air or fluid to escape from the pleural space while simultaneously maintaining an air-tight seal against the entry of outside air.

Persistent bubbling in the suction chamber, while it might occur in certain situations, can signify a leak in the system rather than proper functioning, especially if it occurs continuously and is not just transient. Sensations of discomfort from the patient may indicate complications or improper placement, so their absence alone does not verify functionality. A static fluid level in the collection chamber could suggest that there is no drainage occurring, which would indicate a malfunction or blockage in the system. Thus, fluctuations in the fluid level with breathing events are the primary indicator of correct functioning in a chest drainage system.