Which findings on a post-thoracic-surgery chest X-ray indicate a properly functioning chest tube?

• A. Lung expansion on affected side, persistent pleural space drainage through the tube, and the tube tip in the pleural space as intended.
• B. Lung collapse on affected side.
• C. Tube tip outside the pleural space.
• D. No drainage through the tube.

Answer: (A)

The main idea tested is how to recognize a properly functioning chest tube on a post-thoracic-surgery chest X-ray. A functioning chest tube should be actively draining and allow the lung to re-expand, with the tube tip correctly positioned in the pleural space.

The best choice shows three compatible signs: the lung on the affected side has expanded, indicating the pleural space has been adequately evacuated and the lung can re-expand; there is persistent drainage of the pleural space through the tube, showing ongoing removal of air or fluid; and the tube tip remains in the pleural space as intended, confirming correct placement. Together, these findings demonstrate the tube is in the right place, actively doing its job, and the lung has re-expanded as expected after surgery.

Why the other options don’t fit: lung collapse would suggest the chest tube isn’t effectively evacuating the space or there’s a continue of air or fluid, indicating dysfunction; a tube tip outside the pleural space means malposition and inability to drain the pleural cavity; no drainage through the tube implies blockage or nonfunctioning drainage, not a functioning system.