Pneumothorax

A tall, thin young man suddenly grabs his chest and can't breathe — breath sounds are absent on one side only. Is this a simple pneumothorax that can be observed, or a tension pneumothorax where the clock is ticking?

A pneumothorax occurs when air enters the pleural space, collapsing the lung partially or completely. There are three types the NCLEX tests: spontaneous (often in tall, thin males or those with COPD, no trauma), traumatic (rib fracture, central line placement, mechanical ventilation), and tension — the life-threatening emergency. In tension pneumothorax, air enters the pleural space on inspiration but cannot escape on expiration, creating a one-way valve effect. Pressure builds rapidly, pushing the mediastinum toward the unaffected side, compressing the heart and great vessels, causing obstructive shock. Assessment findings progress predictably: absent breath sounds on the affected side, tracheal deviation away from the affected side (late and ominous), hypotension, tachycardia, jugular vein distension, and subcutaneous emphysema (crepitus under the skin). A simple pneumothorax shows decreased breath sounds, dyspnea, pleuritic chest pain, and hyperresonance on percussion. Chest X-ray confirms simple pneumothorax, but tension pneumothorax is a clinical diagnosis — you do not wait for imaging. Emergency treatment for tension pneumothorax is needle decompression at the second intercostal space, midclavicular line on the affected side, followed by chest tube insertion. Small spontaneous pneumothoraces may resolve with observation and supplemental oxygen, which accelerates reabsorption of pleural air.

Key Distinctions

Don't confuse tension pneumothorax (tracheal deviation AWAY from affected side, absent breath sounds, hypotension) with hemothorax (dullness on percussion, blood in chest). Students mix up tracheal deviation direction — it shifts AWAY from the tension side because pressure pushes structures over. Hyperresonance means air trapping (pneumothorax); dullness means fluid (effusion or hemothorax).

Clinical Pearl

Absent breath sounds + tracheal deviation + hypotension = tension pneumothorax. Don't wait for the X-ray — this triad means needle decompression NOW.