Final answer:
The nurse should document the finding of constant bubbling in the suction control chamber of a chest tube, as it is a normal indication of proper function in maintaining negative pressure in the chest cavity for a patient with pneumothorax.
Step-by-step explanation:
When a nurse observes constant bubbling in the suction control chamber of a patient with a chest tube, it indicates that the system is working to remove air from the pleural space and maintain negative pressure within the chest cavity, which is necessary for proper lung expansion after a pneumothorax caused by blunt trauma. Documenting the finding is the appropriate nursing action in this case, as constant bubbling in the suction control chamber is expected when the suction is active and functioning correctly. It is a normal finding and not an indication of a system malfunction or a patient emergency that would necessitate immediate removal of the chest tube or activation of a Rapid Response Team.