What is the highest priority nursing action when a client's chest tube has dislodged?

When a client's chest tube has dislodged, the highest priority nursing action is to apply a petroleum gauze dressing over the site. This intervention is critical because it helps prevent air from entering the pleural space, which can lead to a tension pneumothorax. The petroleum gauze creates an airtight seal that can help maintain negative pressure in the pleural cavity, which is essential for lung re-expansion and overall respiratory function.

Ensuring the integrity of the pleural space is vital in this situation, as any introduction of air can lead to severe respiratory distress and compromise the client's oxygenation. This dressing acts as a temporary solution until a more definitive treatment, such as reinserting a new chest tube, can be performed.

Applying oxygen via a non-rebreather mask and positioning the client may support oxygenation and comfort but do not address the immediate risk of air entering the pleural space. While preparing to reinsert a new chest tube is a necessary step, it would typically follow the urgent application of a dressing to manage the risk of pneumothorax. Thus, the immediate action required in the case of a dislodged chest tube is to ensure that the site is covered to protect the integrity of the pleural space.