The three general types of injury resulting from lung overexpansion are air embolism, pneumothorax, and ___

• A. tissue emphysema
• B. sinus squeeze
• C. decompression sickness
• D. barotrauma

Answer: (A)

Lung overexpansion injuries happen when air inside the lungs expands during ascent or while holding breath, causing alveoli to rupture. When that rupture occurs, air can escape into different parts of the body. It can enter the bloodstream and cause an air embolism, or leak into the pleural space causing a pneumothorax. It can also track into tissue planes, producing tissue emphysema—air in the tissues such as under the skin or in the mediastinum. This tissue emphysema is the correct third injury because it specifically describes air that has escaped into the body's tissues due to alveolar rupture, completing the trio with air embolism and pneumothorax. Sinus squeeze is a sinus-specific barotrauma, decompression sickness stems from inert gas bubbles forming in tissues from rapid ascent, and barotrauma is a general term rather than the specific third injury in this context.