Which of the following is a primary indication for chest tube placement in adults?

• A. Chronic cough
• B. Uncomplicated small pleural effusion without symptoms
• C. Routine preoperative prophylaxis
• D. Pneumothorax

Answer: (D)

Evacuating air from the pleural space to allow the lung to re-expand is the main goal of chest tube therapy. When air accumulates in the pleural space (a pneumothorax), the lung can collapse and breathing becomes impaired. In adults, the presence of a pneumothorax—especially if it is large, symptomatic, or causing respiratory distress or hemodynamic instability (tension physiology)—is the primary situation that warrants chest tube placement. In an emergency like tension pneumothorax, immediate decompression is needed, followed by chest tube insertion to re-expand the lung and prevent further deterioration.

The other options don’t fit as indications because they don’t involve a clinically significant air or fluid collection in the pleural space requiring drainage. A chronic cough isn’t related to pleural drainage. An uncomplicated small pleural effusion without symptoms can often be observed or treated conservatively rather than drained. Routine preoperative prophylaxis is a general perioperative consideration and not an indication to place a chest tube.

So, the reason this option is best is that a pneumothorax directly creates a space that needs to be evacuated to restore lung expansion, which is the core purpose of a chest tube.