Which condition involves a collapsed lung with unilateral chest rise and decreased breath sounds on one side?

• A. COPD
• B. Anaphylaxis
• C. Hyperventilation syndrome
• D. Spontaneous pneumothorax

Answer: (D)

Recognizing a spontaneous pneumothorax is about identifying a collapsed lung on one side. When air leaks into the pleural space, the lung on the affected side cannot fully expand, so that side of the chest may rise less with each breath. The decreased expansion leads to diminished or absent breath sounds on that side. Patients often report sudden chest pain with shortness of breath. On exam you may also find hyperresonance to percussion on the affected side due to air in the pleural space.

In the field, the focus is on supporting oxygen and monitoring while transporting. Provide high-flow oxygen and reassess frequently. If signs of tension pneumothorax appear—rapid deterioration, hypotension, distended neck veins, or tracheal deviation—treat as an emergency per protocol, because it requires immediate decompression.

The other conditions listed don’t typically present with a sudden unilateral collapse and one-sided reduction in breath sounds. COPD is a chronic, diffuse lung disease with abnormal breath sounds and hyperinflation rather than a new, unilateral collapse; anaphylaxis causes airway swelling and generalized symptoms; hyperventilation syndrome usually presents with rapid breathing but without a new unilateral lack of breath sounds.